Category Archives: Music

Apple Music Memos: Snap Review

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Just had to give Apple Music Memos a try.

Apple Music Memos records your performance, figures out the tempo and chord progression, and plays back the original audio plus a bass and drum accompaniment. Pretty neat.

After installing Music Memos on my iPad, I went up to the studio, turned on my Yamaha PSR-S950 arranger and launched Music Memos. I decided to try a 4/4 song with a simple chord progression — Van Morrison’s Brown Eyed Girl.

What did I learn? First, Music Memos needs a little time at the beginning of a track to figure out the tempo. It displays a vertical line which presumably shows the downbeat or chord change. If you try to keep good time, it will follow your changes. If…

Well, I ain’t no Hal Blaine when it comes to timekeeping! Turn on the S950’s metronome, set it for 110BPM and try again. Unfortunately, the loud sound of the metronome seemed to throw off the chord recognition, etc. Music Memo provides visual feedback of sound level by sending out waves (like a pebble in a pond) around its record button. I decreased the metronome volume so that it wouldn’t trigger Music Memos’ sound detector. The much louder piano sound still picked up.

The third try was the charm. I played a four bar lead in to give Music Memos a good, solid beat before kicking into the tune. I laid down a basic track by playing a piano chord on each downbeat. The second thing I learned is Music Memos does a good job with chord inversions, but doesn’t always recognize a dominant 7th. It got the root and major/minor triad OK, not the flat 7.

With the basic track in place, you can edit the chord progression and make fix-ups. I couldn’t find a way to straighten out timing which is why I resorted to the metronome method. Music Memos desperately needs a metronome even if it is a silent, visual metronome. Apple shouldn’t have any trouble adding this feature to the app.

Now for the fun part. There are two icons at the bottom of the screen: bass and drums. Tap the icons to turn on the accompaniment. If you hold an icon, Music Memos pops up a chart that let’s you change the overall characteristics of the bass or drum accompaniment. You can choose simple vs. complex, etc. I left the settings on the defaults.

OK, plug in the Boss MicroBR recorder, hit RECORD on the MicroBR, hit PLAY on Music Memos and lay down the organ part. True confession. The rehearsal was nice and loose. With the red light ON, things got yippy. It took six takes to get an acceptable demo track. (Hats off to the Wrecking Crew, again.)

Music Memos can probably do more tricks and it will take a little time and practice to work with it. (Drum accompaniment when laying down the initial track?) Here’s the quick demo track just to give you a taste. Total cheesiness is intentional! Musical Doritos. Cha-cha.

(Re)take the stage

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A good show starts in the dressing room
And work its way to the stage
— “Get Dressed” by George Clinton

With Winter NAMM 2016 just a few weeks away, I started thinking about how Yamaha might position a new synthesizer workstation (rumored to have the name “Montage”).

Motif has had a long run as a stage instrument favored by many professional touring musicians. It makes a good master controller for a backstage rig and has a wealth of great native sounds. The synth- and piano-key actions are extremely playable with good key-to-sound response.

Over the last few years, Nord and more recently Korg have been taking the stage away from Yamaha. The Nord Stage and Electro series are firmly established as gig boards and the Korg Kronos is coming on strong. Korg products seem to be sprouting everywhere on The Late Night with Stephen Colbert thanks to John Batiste — who can really rock ’em.

I doubt if Yamaha is willing to surrender the stage. This news may disappoint those players who are hoping for a mind-blowing (virtual) analog synthesizer. As a business-person, I would say, “Hmm, we made good money on the stage and in the studio with Motif. Let’s build on that success. Besides, there are plenty of ’boutique’ vendors who make great instruments, like Dave Smith.” Yamaha even granted the name “Sequential” back to Dave Smith.

Yamaha may see the Nord Stage and Korg Kronos as their primary competition for the stage in the synth workstation space. Both instruments combine multiple synthesis techniques into a single integrated package:

  • Wavetable synthesis including sample playback
  • Analog synthesis
  • Frequency Modulation (FM) synthesis
  • Acoustic and electric piano emulation
  • B3 and combo organ emulation

So, which pieces are missing in the current Motif XF? Are you thinking “Reface” yet?

Let’s look at these aspects in turn.

Wavetable synthesis and sample playback

More than a few Internet posters slag AWM (Advanced Wave Memory). I suspect that many of these people would like real analog or modeled analog instead. That’s OK by me because they probably need those sounds for their music. However, there is a wide customer base who need “traditional” instruments (brass, strings, woodwinds, etc.) where sample-playback still rules. AWM is a very successful sample-playback engine and I don’t see Yamaha abandoning AWM.

Yamaha have a new tone generation engine, the SWP70 . The SWP70 is already at work in the PSR-S970 and PSR-S770 arranger workstations . The SWP70 is more than a sample-playback engine as it also performs programmable digital signal processing for effects and more. The S970 implements Motif-quality sounds and effects including Virtual Circuit Modeling (VCM) and the Real Distortion effects that were added to Motif XF in the v1.5 update.

Other posters feel that an SSD is essential for sample streaming. SSD is only one approach, however, and that approach requires a SATA interface for sample I/O. SSD is not necessarily the cheapest design nor does it minimize latency. Yamaha deconstructed the SSD functionality, threw away the SATA interface cost and latency, implemented an Open NAND Flash Interface (ONFI), and embedded sample data caching into the SWP70. The SWP70 has all of the extensibility of NAND flash without the cost of the SATA controller and without SATA bus latency.

As demonstrated by the S970 and S770, the SWP70 is ready to roll for sample-playback and effects processing.

Analog synthesis and FM synthesis

I contend that the Reface products are a field test for SWP70-based synthesis methods that are not tested by the S970 and S770. I have not yet seen absolute evidence that Reface keyboards use the SWP70, but my suspicion is strong.

The Reface CS and Reface DX demonstrate analog physical modeling and 4-operator FM sound synthesis, probably using the SWP70. Please remember that the SWP70 is not just sample-playback; there are digital signal processors in there. These DSP units can be programmed for effects (reverb, etc.) or sound generation. A computer is a computer whether it is an x86 architecture machine or an embedded DSP. Both the Reface CS and Reface DX implement VCM effects, too.

Two more general points about the Reface line. First, the Reface keyboards use an ARM architecture (FM3) processor for control and user interface. This is a major departure from past Yamaha practice. Next, all four keyboards operate on battery power (six “AA” batteries). Low power operation is a significant engineering accomplishment and means that the SWP70 could be deployed in a wide range of portable products — not true of the previous generation SWP51L tone generator.

Acoustic and electric piano emulation

Yamaha demonstrated its commitment to the stage when it introduced the CP1 stage piano and its siblings. The CP1 was well-received.

The CP1 is a bit of a breakthrough product technically. The acoustic piano is implemented mainly through sample-playback. The CP1 physical wave memory is only 128 MBytes. Yamaha eventually released the CP1 acoustic piano samples for Motif XF as part of the Motif XF Premium Collection. We should expect a CP1-level piano or better in the new workstation.

Yamaha “got away” with so few samples overall because the CP1 electric pianos are implemented using Spectral Component Modeling (SCM). “SCM” covers a family of technologies including spectral modeling synthesis (SMS). SMS replaces gobs of samples with computation (AKA “modeling”). SMS eliminates the nasty sonic artifacts due to velocity switched sample-playback because, well, there aren’t any samples, just lots of computations to be performed very quickly.

The Reface CP uses SCM to implement its electric pianos. The Reface CP sounds great. (See my Reface CP snap review.) The Reface CP re-introduces Formulated Digital Sound Processing (FDSP) to model the electric piano pickup. I expect to see SCM electric pianos and a subset of FDSP in the new workstation.

B3 and combo organ emulation

B3 emulation has never been Motif’s strong suit. Nord, in particular, excel at B3 and rotary speaker emulation. Hopefully, Yamaha have addressed this defficiency by incorporating the Reface YC technology into their new workstation.

The Reface YC provides a live front panel that lets a player control the B3 drawbars, percussion, vibrato and rotary speaker on the fly. The ability to play the bars, etc. is essential to B3 technique. A few important improvements include a rotary speaker brake (STOP) position as well as SLOW and FAST, a vibrato/chorus section, and a full percussion section. Hopefully, the vibrato/chorus section emulates the Hammond vibrato/chorus scanner — an effect that is lacking in the Motif (and Tyros/PSR, for that matter).

The Reface YC implements B3 tonewheels through AWM. Is sample-playback better than Nord’s modeling? Of course, a lot rides on rotary speaker simulation, too. I can’t wait to find out. So far, I haven’t been able to find a Reface YC to try one out! If Yamaha wants to take the stage, again, it needs to nail this one.

The bottom line

Yamaha surely have the basic technology to make a machine for stage performers. Hopefully, they have implemented a user interface that is easy to learn, responsive and fun to play — kind of like the live front panels in the Reface series.

The Tyros and the new S770/S970 arrangers sport large displays. The S770 and S970 wide-screens are really nice. Lately, Yamaha have placed greater emphasis on skeuomorphic user interfaces with virtual knobs, sliders, etc. Whether Yamaha goes for a touch panel, only Yamaha knows at this point. It would be kind of cool to have virtual Reface front panels with finger-tweaking controls. But, would it be playable?

Sixteen days to go to Winter NAMM 2016 …

If you liked this article, you might enjoy:

New Yamaha workstation at NAMM 2016?
Reface YC and DX teardowns
The SWP70 tone generator
PSR-S770 and S970 internal architecture
Reface CP: Yes, I played one!

Copyright (c) 2016 Paul J. Drongowski

New Yamaha workstation at NAMM 2016?

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True gearheads are already making predictions and plans for 2016 Winter NAMM, January 21-24, 2016. Winter NAMM rumors abound including “Montage,” the rumored name for the rumored new Yamaha synthesizer workstation.

See the list of new waveforms in the Montage and read my initial review of the Montage8. Update: May 10, 2016.

Find the latest links, pictures, rumors and facts here . Update: January 21, 2016.

Check out some new thoughts about the rumored workstation and preliminary comments . Update: January 18, 2016.

Many folks — myself included — anticipate the release of a new Yamaha synthesizer workstation at the next NAMM. Much has been made of the registered trademark “Montage.” I don’t really care too much about what they call it, as I care about what it will do.

Last month, I posted two articles about the new Yamaha tone generation chip called “SWP70”:

This chip made its first appearance in the new PSR-S770 and PSR-S970 arranger workstations. Lest anyone scoff, the S770 and S970 produce Motif-caliber sounds including the REAL DISTORTION effects added to the Motif XF by the v1.5 update. The previous tone generator (SWP51L) is used throughout the mid- and upper-range Yamaha keyboard products including Clavinova, MOX/MOXF, Motif XS/XF, and Tyros 4/5. The number of tone generator chips varies by product specification and, most notably, sets the maximum available polyphony. A new tone generator chip is a pretty big deal since it will have an impact on all mid- and high-grade electronic instruments across product lines.

My earlier article about the SWP70 is written from the perspective of a computer architect and is way too nerdy for normal people. 🙂 Let me break it down.

Musicians using VST plug-ins within a PC-based DAW are familiar with the concept of sample streaming. In the quest for greater realism and articulation, sample libraries have become huge. These libraries simply cannot fit into fast random access memory (RAM) for playback. As a work-around, a software instrument reads samples from a drive-based library on demand and only a small part of the entire library is resident in RAM at any given time. The process is often called “sample streaming” because the software instrument streams in the samples on demand from a large fast secondary memory like a Solid-State Drive (SSD). The Korg Kronos workstation caught everyone’s attention because it incorporates an x86-based software system that streams samples from an SSD. (For Kronos-related articles, look here and here.)

The SWP70 combines streaming with tone generation. It does not, however, use an SSD for storage. Rather, it subsumes the functionality of the SSD. A moment to explain…

An SSD consists of three major subsystems: SATA controller, temporary storage cache (RAM) and one or more NAND flash memory chips. The NAND flash memory chips typically adhere to the Open NAND Flash Interface (ONFI) standard. This allows expansion and standardized configurability. The SATA controller exchanges commands and data with a computer using the SATA bus protocol. The temporary storage cache holds data which is pre-read (cached) from the NAND flash chips. Caching is required because random access read to NAND flash is too slow; sequential paged access is much faster. Data must be prefetched in order to achieve anything like SATA 1 (2 or 3) transfer speed.

The SWP70 subsumes the SSD functionality. It has its own memory controller and has a side memory port to its own RAM for caching samples. The SWP70 reads samples from its ONFI-compatible NAND flash memory bus and stores the samples in its cache. The tone generation circuitry reads the samples from the cache when it needs them. The SWP70 solution is, effectively, sample streaming without the added cost and latency of SATA bus transfers. The samples coming into the SWP70 from flash are compressed, by the way, and the SWP70 decompresses them.

The SWP70 will very likely make an appearance in the new Yamaha synthesizer workstation. The S770 and S970 do not make full use of the SWP70, so we have yet to see what this chip is fully capable of. We can definitely expect:

  • Much larger wave memory (4GBytes minimum)
  • Greater polyphony (256 voices or more)
  • More simultaneous DSP effects (32 units or more)
  • The demise of the expensive expansion flash DIMMs

I would simply love it if the new workstation implemented some form of Super Articulation 2 voices (now supported by Tyros 5). The raw resources are there.

User-installed expansion memory may be a thing of the past. The current DIMMs plug into a two channel, full parallel memory interface. That interface is gone and the SWP70 communicates with flash NAND through an ONFI-compatible interface. The Motif and Tyros follow-ons will likely reserve space for user samples and expansion packs in built-in flash memory just like the new mid-range PSRs.

What does Yamaha intend to do with all of this polyphony? Current high-end models like the Tyros 5 use two tone generation chips. Yamaha could replace both chips with a single SWP70 and pocket the savings.

Another possibility is to provide advanced features for musical composition that combine MIDI and audio phrases. Here is a list of technologies covered by recent Yamaha patents and patent applications:

  • Beat detection and tracking
  • Chord detection
  • Synchronized playback of MIDI and audio
  • Combined audio/MIDI accompaniment (time-stretch and pitch-shift)
  • Object-oriented phrase-based composition on a time-line
  • Accompaniment generation from chord chart
  • Display musical score synchronized with audio accompaniment
  • Phrase analysis and selection (via similarity index)
  • Near ultra-sonic communication of control information
  • Search for rhythm pattern similar to reference pattern

A few of these technologies are covered by more than one patent — recurring themes, if you will. I could imagine a screen-based composition system that combines audio and MIDI phrases which are automatically selected from a database. The phrases are transparently time-stretched and pitch-shifted. Some of the compositional aids may be implemented in the workstation while others are tablet-based. The tablet communicates with the workstation over near ultra-sonic sound (no wires, no Bluetooth, no wi-fi, no time lag).

Sample-based tone generators already perform pitch-shifting. That’s how a single sample is stretched across multiple keys. A musical phrase can be pitch-shifted in the same way. As to time-stretching, stay tuned.

Some of these features, like accompaniment generation from a textual chord chart, are more likely to appear in a future arranger workstation product. Making product-specific predictions is a risky business, especially if you want to get it right!

Yamaha — the business — is keenly interested in growth and expanding markets. Management sees opportunity in growth markets like China. The need to combine audio phrases with MIDI is driven by non-Western music: time signatures other than 3/4 or 4/4, different scales, different playing techniques and articulations. These concerns are perhaps more relevant to the arranger product lines. However, phrase-based composition that manipulates and warps audio and MIDI transparently is a basic feature of many DAWs. (Think “Ableton Live.”)

One final theme seems to recur. Yamaha appear to be interested in analyzing and accompanying non-keyboard instruments. The market for guitar-driven accompaniment is much wider and deeper than today’s arranger workstations and is a lucrative target.

Here are links to a few earlier articles, including speculation about the new Yamaha synthesizer workstation:

These articles link to further background information. Of course, we’ll know a lot more once Winter NAMM 2016 is underway!

All site content Copyright © Paul J. Drongowski unless otherwise indicated.

Copy PSR DSP effects (part 4)

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This is part 4 of a series of articles about DSP effects for electric pianos and other electrified instruments like guitar. The first three articles are:

This article covers two more techniques that should help you create and apply DSP effects to PSR/Tyros voices.

Beg, borrow and steal

As Picasso once said, “When there’s anything to steal, I steal.” I’m not encouraging larcency or piracy, but when there’s a good effect in an OTS or voice, copy and paste is the way to go.

I like writing these blog posts because they encourage me to learn more about PSR/Tyros features that I might have ignored or overlooked. Such is the case with the section titled “Disabling Automatic Selection of Voice Sets” in the Reference Manual. This features gives us a way to selectively copy certain aspects of a voice to another (new) voice.

This feature is like a “mini-freeze” that applies solely to VOICE SET, not entire registrations. Navigate to:

    FUNCTION > [E] REGIST SEQUENCE/FREEZE/VOICE SET

then TAB over to the VOICE SET page. There are four buttons at the bottom of the page controlling, respectively, four aspects of voice loading when a voice is selected:

    VOICE
    EFFECT
    EQ
    HARMONY/ECHO

When a button is ON, the corresponding voice parameter settings are loaded automatically from the selected voice. When a button is OFF, the corresponding voice parameters settings are not loaded.

So, if we set the button for EFFECT to OFF, we essentially “freeze” the current effect settings. When we load a new voice, the effects remain the same. This gives us a poor man’s copy and paste between voices.

Let’s say that we like the distortion effect on the “Clavi” voice and want to apply it to “VintageEP”. First, I load the Clavi voice to call up the DSP effect. Then, I navigate to the VOICE SET page (as described above) and turn the EFFECT button OFF. This freezes the effect part of the voice programming. Then, I select the VintageEP voice. Voila, the VintageEP voice plays using the distortion effect that was frozen.

Stop! Wait a minute!

Once you save the VintageEP voice to the USB drive or an OTS button, be sure to unfreeze the EFFECT aspect of voice loading. If you don’t do this, you will surely wonder why all of the voices you load are distorted!

Hey, where’s the loot?

The built-in voices are the most obvious source of inspiration for new basic voice plus effect combinations. Yamaha need to maintain backward compatible voices, however, and the older voices such as the electric pianos may not use the latest and greatest effects (e.g., REAL DISTORTION). The guitar voices tend to turn over more quickly and adopt the latest effects.

Backward compatibility is less of an issue for the OTS voices within styles. You are more likely to find new and interesting effects under the OTS buttons. Take the built-in “WahClavi” voice, for example. The built-in voice uses the old CLAVI TC.WAH effect. The “WahClavi” voice in the JazzFunk style, on the other hand, uses the new REAL DISTORTION multi-effect MLT CR WAH (Multi FX Crunch Wah).

The following table is a list of OTS voices showing the parent style and DSP effect. Follow this map to find buried treasure!

Voice            Style          S950 effect   Tyros 5 effect
---------------  -------------  ------------  -------------------------------
GrungeGuitar     JazzFunk       AMP1 HEAVY    British Combo Heavy
OverdriveWah     JazzFunk       MLT CR WAH    Multi FX Crunch Wah
VintageAmp       Soul           V_DIST SOLID  V_Dist Solid
Slapback         MotorCity      V_DIST ROCA   V_Dist Roca
SingleCoilClean  Live8Beat      CMP+OD+TDLY4  Compressor+Overdrive+TempoDelay4
JazzClean        KoolShuffle    V_DST JZ CLN  V_DistJz Cln
StageLead        HardRock       MLT DS SOLO   Multi FX Distortion Solo
EarlyLead        FunkPopRock    TEMPO AT.WAH  Tempo At.Wah+
MetalMaster      ContempRock    ST AMP DS     Small Stereo Distortion
ElectroAcoustic  AcousticRock   AMP1 CLASSIC  British Combo Classic
BluesyNight      70sGlamPiano   ST AMP VT     Small Stereo Vintage Amp
PureVintage      60sRock&Roll   MLT OLD DLY   Multi FX Oldies Delay

VintageEP        SoulBrothers   AMP1 CLASSIC  British Combo Classic
WahClavi         JazzFunk       MLT CR WAH    Multi FX Crunch Wah
SuitcaseEP       Live8Beat      CELESTE2      Celeste 2
ElectricPiano    FunkyGospel    EP AUTOPAN    EP Autopan
CP80             FunkPopRock    T_PHASER1     T Phaser 1
JazzVibes        DetroitPop2    VIBE VIBRATE  Vibe Vibrato
VintageEP        60sPopRock     EP TREMOLO    EP Tremolo

HoldItFast       LiveSoulBand   DIST SOFT2    Distortion Soft 2
WhiterBars       Soul           V_DIST CLS S  V_Dist Cls S
WhiterBarsFast   GospelSwing    ST AMP CLEAN  St Amp Clean
CurvedBars       MotorCity      ST 3BAND EQ   St 3Band EQ
EvenBars         FunkyGospel    ST 3BAND EQ   St 3Band EQ
AllBarsPhase     FunkPopRock    PHASER2       Phaser 2
ClassicBars      BluesRock      ST AMP CLEAN  St Amp Clean
Organ-a-Gogo     70sDisco2      V_DIST TWIN   V_Dist Twin
R&B Tremolo      60sVintageRock DIST HARD2    Distortion Hard 2
OrganFlutes      60sPopRock     AMP2 CLEAN    British Legend Clean
OrganFlutes      6-8SlowRock    ROTARY SP1    Dual Rot BRT

GrowlSax         SoulBrothers   V_DST S+DLY   V Distortion Soft + Delay
GrowlSax         MotorCity      V_DST H+DLY   V Distortion Hard + Delay
RockSax          LiveSoulBand   DST+DELAY1    Distortion + Delay 1
RockSax          HardRock       ST AMP CLEAN  St Amp Clean
Harmonica        6-8Soul        TEMPO AT.WAH  Tempo At.Wah+

Use the poor man’s copy and paste method to mix and match a basic voice sound with a DSP effect. The treasure map demonstrates how the Yamaha style programmers make use of the workstation’s sonic resources. There’s a lot to learn here!

Dry/Wet mix

I like to change voices by hitting the OTS buttons while jamming along with a tune. I have created more than 50 styles with customized OTS buttons to cover my current repetoire. The OTS buttons select the voice and effect combinations that are the most approprtiate for specific tunes (appropriate to my ears anyway).

Unfortunately, the kind of OTS voice and effect informaton that can be stored is limited by the S950’s operating system. (See the Voice Effect, Voice Set, and Mixing Console sections of the Parameter Chart in the Data List manual for the exact details.) An OTS button remembers:

  • DSP effect type (insertion type)
  • DSP ON/OFF
  • DSP variation ON/OFF
  • DSP variation value
  • DSP depth

for the RIGHT1, RIGHT2 and LEFT parts.

If you cast your mind back to Part 1, you know that there are a lot of parameters behind each effect. These parameters cannot be directly captured in an OTS button, which is why they must be stored in a USER EFFECT memory location as described in Part 2. You do get a fly-speck of tweakability by modifying the DSP variation value. Unfortunately, the parameter type is fixed.

The OTS restrictions are relieved or eliminated in the PSR-S970. Again, please see the Parameter Chart in the Data List manual.

Fortunately, OTS remembers DSP depth. The DSP depth controls the “dry/wet” mix, that is, the amount of uneffected (dry) and effected (wet) signal that is mixed together and sent further along (usually to the system-level chorus and/or reverb blocks).

Let’s say that you added a heavy distortion sound to the “SuitcaseEP” voice and you want to reduce the amount of distortion without changing the tone. (Guitar distortion is often waaaay too much for electric piano.) Simply dial down the DSP depth. This increases the amount of dry (clean) electric piano sound and decreases the amount of wet (distorted) electric piano sound. Voila, an electric piano with a bit of grit, not a fuzzed out shredder’s delight.

Here are the parameters for the DISTORTION presets DIST SOFT1 and DIST SOFT2.

                       DIST SOFT1  DIST SOFT2
                       ----------  ----------
    Drive                 16           7
    Amp Type             Tube        Combo
    LPF Cutoff          4.5 KHz     3.6 KHz
    Output Level          64          82
    Dry/Wet              D44>W      D<W63
    Edge (Clip Curve)     49          40

The built-in preset “Clavi” voice uses DIST SOFT1 to get its biting tone. Note that the DIST SOFT1 dry/wet mix has more dry signal than wet and that the DIST SOFT2 dry/wet mix has more wet signal than dry.

Here’s where things are cool, confusing, or both. The S950 seems to know when a DSP effect has a predefined dry/wet mix parameter. The parameter value tracks the DSP depth knob in the Mixing Console. Cool. The DSP depth knob is calibrated from 0 to 127 while the dry/wet parameter is calibrated from full dry (D63>W) to full wet (D<W63). Confusing. Internally, a 50-50 dry/wet mix (D=W) is represented by the value 64. The dry/wet mix is 50-50 (D=W) when the mixing console DSP depth knob is set to 64; the knob determines the internal value. (Pan gets munged in a similar way.)

As an exercise, I suggest applying the distortion effect in the built-in “Clavi” voice to “SuitcaseEP.” Then, use the DSP depth (dry/wet mix) to dial back (or dial up!) the distortion to taste.

A loose end

Some of you probably noticed that I didn’t say much about the “Wah Pedal” parameter belonging to the REAL DISTORTION multi-effect algorithm. This parameter can be swept by an XG “assignable controller.”

I didn’t say much about the “Wah Pedal” parameter because I was hoping to find a way to control this parameter from either the expression pedal input or an external MIDI controller. It may be possible to set up external control if a controller can utter the right SysEx mumbo-jumbo to set up an XG assignable controller. The process looks beastly and not very practical.

However, the S970 and Tyros 5 are capable of sweeping the wah pedal parameter. Please see the reference manual concerning “Footswitch / Foot Controller Settings”.

Multi-effects for electric piano (Part 3)

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This is part 3 of a multi-part series about PSR/Tyros effects for electric piano.

PSR effects for electric piano (Part 1) presents a basic approach to grunging up an electric piano sound with distortion (amp simulation). Editing and saving PSR effects (Part 2) describes how to save a custom PSR/Tyros effect to USER EFFECT memory. In this part, I’ll cover the REAL DISTORTION multi FX algorithm.

If you’re a real gear-head, you probably heard about the new Yamaha Reface mini keyboards including the Reface CP, which is rich in electric pianos. (See my snap-review of the Reface CP.) Aside from good samples, it’s the effects that make the Reface CP a winner. The Reface CP has an effects chain driven by the basic EP voice:

              Tremolo       Chorus       Digital Delay
   Drive -->     X     -->     X    -->         X       -->  Reverb
                Wah         Phaser        Analog Delay

Switches select between Tremolo and Wah (or pass-through), between Chorus and Phaser (or pass-through), and between Digital Delay and Analog Delay (or pass-through). Thus, either Tremolo or Wah is active, but not both at the same time, etc. Each effect has one or two knobs that control the most basic parameters:

  • Drive: Amount of distortion (including none)
  • Tremolo/Wah: Depth and Rate
  • Chorus/Phaser: Depth and Speed
  • Digital Delay/Analog Delay: Depth and Time
  • Reverb: Depth (including none at all)

The front panel controls let you tailor your sound, e.g., maybe a little distortion (Drive) followed by Tremolo and some Reverb.

This article shows you how to make a similar effects chain on your PSR/Tyros. I assume that reverb is applied by the PSR/Tyros REVERB effect block, so I won’t discuss reverb here.

If you have a late-model Yamaha arranger workstation (PSR-S950 or later, Tyros 5 or later), Yamaha have already done much of the work for you. These workstations are equipped with REAL DISTORTION effects. One of the REAL DISTORTION effect types is a multi-effect. On the PSR-S950, look for the effect presets called “MLT DS SOLO,” etc. The “MLT” stands for “MULTI.”

A little product family history. The REAL DISTORTION effects first appeared in the Version 1.5 Motif XF upgrade. Yep, these are among the latest effects in the Motif series. Yamaha implemented all of these effects in the Tyros 5 and about half of these effects in the S950. Yamaha added the rest of the REAL DISTORTION effects to the S970. Fortunately, S950 owners have the versatile “Multi FX” algorithm (effect type).

If you don’t have REAL DISTORTION effects, you’re not totally out of luck. Look in the Data List manual and find combination effects (distortion plus delay, etc.) and use them instead. You won’t have as many effect stages, but the approach still applies.

The REAL DISTORTION MLT effect chain is quite complete:

                                                  Vibe       Chorus
Compressor --> Wah --> Distortion --> Speaker --> Phaser --> Flanger
                                                  Tremolo    Delay
                                                             Echo

The effect chain is really intended for guitar, but hey, people in the sixties and seventies put electric pianos through stomp boxes and guitar amps.

There are six REAL DISTORTION multi-effect presets: MLT DS SOLO, MLT DS BASIC, MLT OD CHO, MLT CR WAH, MLT OLD DLY, and VINTAGE ECHO. Use these as starting points for your experiments. I suggest starting with VINTAGE ECHO as it is the cleanest of the lot. Do what guitarists do — dive in and tweak.

Here is a list of the parameters and the allowed values. See the full information in the REAL DIST section of the Data List manual.

#   Parameter      Display
--  -------------  ---------------------------------------------
1   Comp. Sustain  Off, 0.1 - 10.0
2   Wah Sw         Off, Wah Pedal, Auto+Full, Auto+Mid,
                   Auto+Light, Auto-Full, Auto-Mid, Auto-Light
3   Wah Pedal      0-127
4   Dist Sw        Off, Overdrive, Distortion1, Distortion2,
                   Clean, Crunch, Higain, Modern
5   Dist Drive     0.0-10.0
6   Dist EQ        High Boost, Mid Boost, Mid Cut 1, Mid Cut 2,
                   Mid Cut 3, Low Cut 1, Low Cut 2, High Cut,
                   High/Low
7   Dist Tone      0.0-10.0
8   Dist Presence  0.0-10.0
9   Output         0-127
10
11  SP Type        Off, Stack, Twin, Tweed, Oldies, Modern, Mean,
                   Soft, Small, Dip1, Dip2, Metal, Light
12  LFO Speed      0.1Hz . 9.925Hz (table#27)
13  Phaser Sw      Off, Standard, Wide, Vibe, Tremolo
14  Delay Sw       Off, Delay M, Echo1 M, Echo2 M, Chorus M,
                   Dl Chorus M, Flanger1 M, Flanger2 M,
                   Flanger3 M, Delay St, Echo1 St, Echo2 St, 
                   Chorus St, Dl Chorus St, Flanger1 St, 
                   Flanger2 St, Flanger3 St
15  Delay Ctrl     0-127
16  Delay Time     0-127

The parameters look overwhelming, so let’s break things down.

There are six “switches” that turn effects on and off. In a few case, the switches also select the flavor of the effect when it is turned on. For example, “Dist Sw” turns off the effect in the chain or turns on one of the seven available distortion types (Overdrive, Distortion1, etc.) In addition to switches, there are effect-specific knobs. “Dist Drive,” “Dist EQ”, “Dist Tone” and “Dist Presence,” for example, change the sonic characteristics of the distortion effect.

The “Delay Sw” acts like one of the switches on the Reface CP. “Delay Sw” disables the effect stage, or it turns on a delay, echo, chorus or flanger effect. Some effects are mono (M) and some effects are stereo (St). The “Phaser Sw” switch disables the stage (off) or it turns on a phaser (type: standard, wide, vibe) or tremolo effect.

The Low Frequency Oscillator (LFO) Speed parameter controls the effects that need modulation: phaser, chorus, flanger, tremolo, etc. You need to dial in the appropriate LFO frequency for the modulation effect type.

Wow, that’s a lot of choices! Here is a table of the parameter values for each preset.

    MSB/LSB --->  95/32     95/33     95/34     95/35     95/36     95/37
#  Parameter     DS SOLO   DS BASIC   OD CHO    CR WAH   OLD DLY   VINT ECHO
-- ------------- --------  --------  --------  --------  --------  ---------
1  Comp. Sustain   3.6       3.2       3.6       3.6       4.0       3.6
2  Wah Sw          Off       Off       Off     Auto+Mid    Off       Off
3  Wah Pedal        0         0         0         0         0         0
4  Dist Sw       Distort1  Distort1 Overdrive   Crunch    Clean     Clean
5  Dist Drive      5.0       4.1       3.8       5.0       5.0       6.6
6  Dist EQ       Hi Boost  MidBoost  MidCut2   LowCut1   Hi Boost  MidBoost
7  Dist Tone       2.4       5.6       5.6       4.2       3.0       4.6
8  Dist Presence   4.8       5.6       5.0       5.2       5.6       5.0
9  Output           55        60       102        95       121       113
10
11 SP Type        Twin      Stack     Tweed     Stack     Oldies    Twin
12 LFO Speed      0.1Hz     0.1Hz     0.1Hz    1.167Hz    0.1Hz    0.142Hz
13 Phaser Sw       Off       Off       Off       Off       Off      Off
14 Delay Sw      Echo1 St  Delay St  ChorusSt  Delay M   Delay M   Echo1 M
15 Delay Ctrl       40        26        20        13        24       20
16 Delay Time       48         2        46        36        20        6

These parameter values should give you some starting points for exploration.

If you’re not a guitarist, terms like “presence” may not be meaningful to you. Here are a few helpful definitions taken from Yamaha documentation.

  • Drive: Determines the extent to which the sound is distorted.
  • LFO Speed: Frequency of delay modulation (chorus, flanger), Modulation frequency (tremolo), Frequency of phase modulation (phaser), Frequency at which wah filter is controlled (wah)
  • Delay Time: Determines the delay of the sound in absolute time.
  • Output: Determines the level of the signal output from the effect block.
  • Presence: This parameter of the Guitar Amp effect controls high frequencies.
  • SP Type: Selects the type of speaker simulation.

Why start with VINTAGE ECHO? This preset adds a modest amount of compression and sends the signal through the Clean guitar amp model. The Clean model does not dirty up the sound too much. Rock guitarists — especially guys with mullets — like a lot of distortion. Electric piano, not so much. The Mid Boost adds guts to the midrange frequencies making an EP sound fuller, with guts. Finally, the distorted signal is sent into a Twin speaker model and then a light echo. The Twin model sounds like it would be Fender Twin-ish and similar to the kind of speaker used with a Rhodes EP.

I’ll close with an example USER EFFECT that I called “DirtyChorus.” The chain starts out with compression and a little bit of overdrive and mid-range boost. The distorted signal goes into a nice stereo chorus. I copped the chorus paremeters from the MLT OD CHO preset. I tried different speaker models and liked the sound of the Mean speaker type. Finally, I dialed up the output level to compensate for the low amount of overdrive. 

    Comp Sus       5.0
    Wah Sw         Off
    Wah Pedal      0
    Dist Sw        Overdrive
    Dist Drive     1.4
    Dist EQ        Mid Boost
    Dist Tone      3.2
    Dist Presence  1.3
    Output         120
    SP Type        Mean
    LFO Speed      0.1Hz
    Phaser Sw      Off
    Delay Sw       Chorus St
    Delay Control  20
    Delay Time     46

Dist Drive can be increased before the distortion sounds guitar-ish. Generally, the output level must be lowered when more drive is applied. Clipping-induced distortion is not pretty. Of course, if you like that sort of thing, please carry on.

PSR effects for electric piano (Part 1)
Editing and saving PSR effects (Part 2)
Multi-effects for electric piano (Part 3)
Copy PSR DSP effects (part 4)

All site content is Copyright © Paul J. Drongowski unless otherwise indicated.

PSR effects for electric piano (Part 1)

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A common complaint about the electric pianos on the Yamaha PSR arranger workstations is their lack of “guts” or “grit.” The voice samples are reasonably good, but the effects programming is vanilla and way too polite, especially for rock and soul styles. Here is a table showing the default DSP effect for some of the electric piano voices in the PSR-S950:

    PSR-S950 voice  Category     Effect
    --------------  ----------   -----------------------
    SparkleStack    CHORUS       CHORUS3
    SweetDX         CHORUS       CHORUS3
    BalladDX        CHORUS       ENS DETUNE1
    DX Dynamics     CHORUS       CHORUS2
    BalladBells     CHORUS       CHORUS3
    SuitcaseEP      CHORUS       CELESTE2
    VintageEP       TREMOLO      EP TREMOLO    [DSP off]
    CP80            CHORUS       CHORUS3
    StageEP         CHORUS       CELESTE2
    SmoothTine      SPATIAL      EP AUTO PAN
    ElectricPiano   SPATIAL      EP AUTO PAN   [DSP off]
    Clavi           DISTORTION   DIST SOFT1
    WahClavi        WAH TCH/PDL  CLAVI TC.WAH
    PhaseClavi      PHASER       EP PHASER2

You can see that most of the voices use a chorus effect. In two cases, the DSP effect is turned off by default. (You need to turn it on using the [DSP] front panel button.) The Clavinet voices are a little more fun and use distortion, wah and phaser.

Chorus does not add much “heft” to a voice and it doesn’t add grit. Compression, mid-range boost (EQ) and overdrive are better choices when you need a punchy and/or grungy electric piano sound.

Let’s take a look at the effects programming for a few electric piano voices on the Yamaha MOX synthesizer workstation. The basic voices drive two insert effects connected in series:

    MOX voice             Insert A     Insert B
    --------------------  -----------  -----------
    Crunchy Comp          MltBndComp   CompDistDly
    Vintage Case          AmpSim 2     Auto Pan
    Chorus Hard           ClassicComp  SPX Chorus
    Drive EP AS1          AmpSim 2     Auto Pan
    Natural Wurli         AmpSim 1     Tremolo
    Wurli Distortion AS1  Tremolo      CompDistDly

On the MOX, every voice uses compression, amp simulation or distortion, even the voices employing the evergreen tremolo, pan and chorus effects.

At this point, PSR users tend to throw up their hands and say, “Well, that’s the Motif series!” and back away. Yamaha — bless them — share technology between workstation products. Quite often, you can find the equivalent PSR effect algorithm for an MOX (MOXF) or Motif algorithm.

Consider the MOX “AmpSim2” algorithm. This algorithm shares the same parameters as the PSR “DISTORTION AMP SIM2” algorithm. Here is a table showing the corresponence between MOX and PSR.

    MOX parameter  PSR parameter  MOX value
    -------------  -------------  ---------
    Preset         n/a            Stack1
    AmpType        AMP Type       Tube
    OverDr         Drive          16
    OutLvl         Output Level   70
    LPF            LPF Cutoff     6.3KHz
    Dry/Wet        Dry/Wet        D<W30

The parameter values given here are taken from the MOX “Drive EP AS1” voice. Bring up a PSR voice like “VintageEP,” edit its DSP effect and replace the tremolo effect with “AMP SIM2.” Plug in these values, listen and tweak!

My second example is taken from the MOX “Natural Wurli” voice. The MOX effect algorithm name is “Amp Sim1”. The equivalent PSR effect algorithm is “DISTORTION V_DIST WARM” and its siblings. Here is the equivalency table:

    MOX parameter  PSR parameter  MOX value
    -------------  -------------  ---------
    Preset         n/a            Stack2
    OverDr         Overdrive      2%
    Device         Device         Vintage tube
    Speaker        Speaker        Stack
    Presence       Presence       +10
    OutLvl         Output Level   53%
    Dry/Wet        Dry/Wet        D<W1

Again, change the PSR DSP effect to “V_DIST WARM” and plug in the values. Then, tweak away.

The final example is a multi-effect taken from the MOX “Wurli Distortion AS1” voice. The MOX effect algorithm is “CompDistDly” that is a compressor, distortion and delay effect chain. The equivalency table is:

    MOX parameter  PSR parameter         MOX value
    -------------  --------------------  ---------
    Preset         n/a                   Hard1
    OverDr         Overdrive             15%
    Device         Vin_tube              Vintage tube
    Speaker        Stack                 Stack
    Presence       Presence              +10
    DelayL         Delay Time L          307.3ms
    DelayR         Delay Time R          271.7ms
    FBTime         Delay Feedback Time   306.6ms
    FBLevel        Delay Feedback Level  +31
    FBHiDmp        Feedback High Dump    0.8
    OutLvl         Output Level          22%
    DlyMix         Delay Mix             0
    Compress       n/a                   -29dB
    Dry/Wet        Dry/Wet               D<W12

The almost equivalent PSR effect algorithm is “DISTORTION+ V_DST H+DLY”. The PSR algorithm is missing the compression component (parameter). If you want compression, then consider one of the other PSR distortion algorithms with mono delay.

Keep thinking “multi FX.” I’m going to visit the REAl DISTORTION multi FX algorithm in a future post.

Some of the MOX voices use VCM effects. I didn’t deconstruct the voices with VCM effects because my S950 doesn’t have them. However, if you have VCM effects, for heaven’s sake, use them!

Learn how to save your new creation in Editing and Saving PSR Effects (Part 2).

PSR effects for electric piano (Part 1)
Editing and saving PSR effects (Part 2)
Multi-effects for electric piano (Part 3)
Copy PSR DSP effects (part 4)

Chord Tracker revealed

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I am using the Yamaha Chord Tracker app to figure out the chords to some tunes. Chord Tracker analyzes the music in an MP3/audio file and displays a chord chart. This is great for learning new tunes and working out arrangements.

Chord Tracker can do much, much more! Yamaha really needs to produce a manual for this app to reveal all of these functions. Here are some useful tips including how to send a MIDI file for a transcribed song to your Yamaha PSR/Tyros arranger for playback.

First off, you can change the chords in the chord chart. If you don’t like a chord, just tap the chord and select a new one. Chord Tracker does a pretty decent job of identifying chords in “simple” music. For example, it did a great job with Hot Chocolate’s “Every 1’s A Winner.” (My guilty pleasure.) It didn’t do such a good job with Groovy Waters downtempo “Wicked Game.” The jazz chords (Dm/Eb, come on, man) threw Chord Tracker off. No problem, just edit the chord chart.

Here’s a crazy idea. Use a DAW to produce a three minute song with one or two chords at the beginning. Transcribe the song with Chord Tracker. When you need to create a new song from scratch, edit the new chords. Presto, a chord chart editor.

Next, you can send the chord progression to your PSR/Tyros. The Yamaha web site touts wireless connection, but you can send the song file via wired USB. I transferred the chord progression to my S950 using the Apple Camera Connection kit. (My iPad is a gen 4 running iOS9, BTW.)

The Yamaha web page for Chord Tracker states that Chord Tracker is compatible with the currently listed “Related Products.” That is true. However, Chord Tracker worked successfully with the S950 (not listed). So, even though you don’t own the latest and greatest, please give this capability a try.

On the iPad side, you need to establish a connection from Chord Tracker to your keyboard. Plug in the Camera Connection Kit and USB cable first. Then select your instrument in the Connection box on Chord Tracker’s main screen.

Choose an audio song to transcribe to a chord chart and turn Chord Tracker loose. Once you have a chord chart, tap the upload icon, i.e., that square box with an arrow shooting upward. Then tap the “Send to Instrument” button. Chord Tracker pops up a dialog in which you can enter/change the name of the song file to be created on the arranger workstation. Tap SEND and Chord Tracker sends the song file to the arranger.

Chord Tracker stores the song file in the arranger’s internal drive. It creates a directory named “ChordTracker” and stores the song file in this directory. Any other song file that you create this way is stored in the “ChordTracker” directory.

Press the SONG SELECT button on the arranger to find and select the song file. Navigate to the USER tab of the internal drive and then press the corresponding button for the “ChordTracker” directory. Then press the corresponding button for the song file itself, e.g., “every1s”, which is the name that I gave to the “Every 1’s A Winner” song file.

Press the play button. The arranger will play back the song using the currently selected style and section. Now have fun changing the style, section, tempo and so forth. You can change the style, section, etc. in real time while the song plays, making it easy to tune the song to your sonic wishes.

Of course, you can dive into SONG CREATOR and tweak away. The System Exclusive TAB reveals much of the magic behind the scenes.

Chord Tracker generates three MIDI metadata records for time signature, key signature and tempo, followed by three System Exclusive messages:

    F0 7E 7F 09 01 F7             GM reset
    F0 43 10 4C 00 00 7E 00 F7    XG system ON
    F0 43 60 7A F7                Accompaniment start

The preamble is followed by a slew of Yamaha System Exclusive messages for the chord changes:

    F0 43 7E 02 34 00 34 7F F7    Chord control (F maj/F)
    F0 43 7E 00 08 7F F7          Section control (MAIN A ON)
    F0 43 7E 02 23 00 23 7F F7    Chord control (Eb maj/Eb)

Chord Tracker does not generate the Yamaha proprietary CdS1 chunk in the MIDI file. All playback is controlled by metadata and System Exclusive messages.

We can expect to see more of these kinds of features from Yamaha. They have a US patent (number 9,142,203) for a formatted chord chart and accompaniment generator. The generator is driven by a simple, free form text chord chart.

All site content is Copyright © P.J. Drongowski unless otherwise indicated.

Innards of Krome and Kronos

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Plenty of discussion about Korg Kronos and x86 on the Keyboard Magazine forum, so it’s time to study up on Korg architecture and formulate an opinion.

Before diving in, I should say that I try to get my information from primary sources (e.g., service manuals) and to not rely on Internet “truthiness.” The Web is filled with people who want to believe something whether they are informed or not. Thanks, Stephen Colbert, for the notion of truthiness!

Not all service manuals are readily available (at no cost!), making the narrative a bit sparse. Nonetheless…

Korg have two distinct paths which have led to the current Kronos and Krome. My simplified take on the first thread of Korg workstation history is, starting from Triton:

  • Triton family begat the
  • M3 which begat the
  • M50 which begat the
  • Krome.

The second major historical thread is the multi-faceted OASYS which begat the Kronos series. Along side all of this “begatting,” Korg developed its professional arranger workstations, e.g., the PA80, PA500, etc. leading to the current PA900 and PA4x. The arranger workstations are kin to the Triton, M-series, and Krome, and share much of the underlying hardware technology.

Let’s take the Krome first because it is the most similar to Yamaha and Roland architecture.

The Korg Triton LE was released in 2002 and is a stripped down version (no sampling, no ribbon controller, smaller display, etc.) of the classic Triton. Its embedded CPU is a Renesas SH7043A, the same choice as Roland and Yamaha in that era. The embedded CPU handles all of the user interface (UI) processing and communicates with the keyboard, knobs, LCD and so forth. Samples are generated by a Korg proprietary tone generator chip designated “TGL96” or MB87F1710-PFV-G-BND. The TGL external clock frequency is 24.576MHz. The tone generator has a dedeicated memory channel to 32MBytes of wave ROM. Overall, the Triton LE internal architecture is similar to corresponding Yamaha and Roland products.

The TR61 was released in 2006 and resembles the Triton LE. It has more physical wave ROM (64 MBytes), USB-to-PC communication and an SD card slot. The embedded CPU is a Renesas SH7043A which, again, handles the UI components. The Korg proprietary tone generator chip is designated “TGL96” or MB87F170-PFV-S. Although the parts list uses the same identifier as the LE, this chip is probably just a slightly updated model in the same TGL family.

Korg marketing called its Triton-era synthesis “HI,” or “Hyper Integrated” synthesis. The PA80 arranger also uses HI synthesis and a Korg MB87F1710-PFV-S TGL96 tone generator. Thus, synths and arrangers using HI synthesis probably contain some variant of the MB87F1710 TGL family.

Skipping ahead to the M3 (released in 2007), the tone generator is designated TG01 or MB87M4080PB-GE1. Korg marketing switched to “Enhanced Definition Synthesis” or “EDS.” This chip is clocked using an external 24.576MHz crystal, yielding an internal clock speed of 98.304MHz. The TG01 has two dedicated memory channels (upper and lower PCM data bus) to wave ROM. The TG01 has a third memory channel to an 8MB DRAM for DSP working storage.

The main CPU in the M3 is a a Freescale MC9328MX1 ARM processor. The ARM is clocked at 196.608MHz. The M3 also uses a Renesas H8 (HD64F3687GFPV) for key scanning. H8s are 16-bit processors that are good for interface and “microcontrol.” The Freescale MC9328MX1 is the first appearance of an ARM processor in Korg synth. Yes, that’s right, folks. Korg have used embedded ARM processors since 2007.

The EXB-RADIAS is a synthesizer/vocoder option board for the M3 that uses Korg MMT (Multiple Modeling Technology). The EXB-RADIUS is no processing slouch, consisting of a Renesas SH7709S CPU and two Texas Instruments TMS320VC5502 DSP processors.

I located a service manual for the PA500 arranger from the same era (2007). The PA500 arranger implements EDS and contains a Korg MB87M4080PB-GE1 tone generator IC. The Freescale MC9328MX1 performs the work of a master embedded CPU (user interface, USB interface, LCD control, keyboard input, MIDI interface, etc.) The ARM core clock is 200MHz — fast enough for control, not fast enough for DSP. The DSP is handled by the MB87M4080PB tone generator.

Completing the early picture, the M50 (released 2008) is a reduced feature version of the M3. The M50 implements EDS and contains a Korg MB87M4080 tone generator.

I could not find a service manual for the Krome. Grainy images of its KLM-3119 motherboard show a Korg MB87M4080 TG01 tone generator and what is probably a TI OMAP ARM processor. Clock frequencies cannot be determined from pictures alone. The designers likely replaced the Freescale processor with the Texas Instruments OMAP. Korg marketing changed the pitch name to “EDS-X (Enhanced Definition Synthesis-eXpanded).” The meaning of “expanded” is not clear although the Krome supports more polyphony than the M50. The Krome employs an internal 4GByte micro SD card for sample storage. The TG01 appears to be driven by two ISSI IS42S16160G 256Mbit DRAMs which are organized 16Mx16bits. Very likely, samples are loaded into these DRAMs by the OMAP on demand. The SD card is relatively slow and continuous streaming from SD to the TG, to me, seems unlikely.

Up to this point in the narrative, we know that Korg have at least two generations of proprietary tone generator chip families:

MB87F1710     Hyper Integrated (HI) synthsis
MB87M4080PB   Enhanced Definition Synthesis (EDS)

Whether EDS-X represents a third generation is open to question. Summarizing further, Korg use ARM processors (low clock rate, low power) to handle UI and control tasks.

A desire for additional synthesis methods led to the Korg OASYS. The OASYS is built around the AOpen MX4GVR-GN micro-ATX motherboard (Intel Socket 478). The motherboard is fitted with an Intel 2.8GHz Pentium 4 processor and a minimum of 1GByte of RAM. The OASYS requires a fair bit of additional logic to handle all of the I/O and user interface including a Renesas H8 and a Texas Instruments embedded DSP. The operating system is a custom version of Linux.

Customers found the OASYS to be too expensive and about 3,000 were sold. Having learned from this experience, Korg developed the lower cost Kronos series. There are three major models in the series, where each model is built around a particular mini-ITX, x86 motherboard:

Kronos Lot A  Intel BLK D510M0      Intel 1.66GHz D510 dual-core Atom
Kronos Lot B  Intel D525MW          Intel 1.80GHz D525 dual-core Atom
Kronos X      Intel D525MW          Intel 1.80GHz D525 dual-core Atom
Kronos 2      ASRock IMB-140D Plus  Intel 1.86GHz D2550 dual-core Atom

The motherboard connects to an SSD memory device via SATA2 and to an ARM processor via USB. The ARM processor handles UI and interfacing duties just like the ARM processor in the Krome. The x86-based motherboard performs synthesis. Thus, the Kronos internal architecture is like the synths in the Krome line except the proprietary tone generator IC is replaced by an x86 motherboard running Linux! This internal organization gives Korg substantial cost savings over the OASYS.

According to Dan Phillips (Korg R&D), “… all synthesis, effects, and audio processing is done within the Intel CPU, and naturally the sequencer and KARMA as well.”

Two types of ARM processors were used: Texas Instruments Sitara AM1806BZWT3 (early models) and Texas Instruments AM1808BZWT3 (later models). I’ll focus on the AM1808. The AM1808 system on a chip (SOC) has an ARM926EJ-S core, 16KB I-cache, 16KB D-cache, 8KB RAM (vector table), 64KB built-in ROM (boot image), 128KB system RAM and a host of built-in interfaces (LCD, USB, SPI, etc.) The wealth of interfacing options makes this kind of ARM SOC ideal for embedded applications. The NEON signal processing extension supports 16-bit fixed point arithmetic including a single-cycle multiply-accumulate (MAC) unit. Hardware floating point is not supported. Although the NEON extension is handy, the heavy DSP is performed by the x86.

ARM core clock speed is a function of core voltage, external crystal frequency and software-level configuration. The external oscillator frequency (24MHz) and core supply voltage (1.2V) point toward a 375MHz core clock speed. In any case, the AM1808’s maximum supported speed is 456MHz. The ARM processor — unlike the high frequency dual-core Atoms — dissipates relatively little heat and does not require a heat sink and/or fan.

At this point, we have accumulated enough information to compare Krome’s synthesis hardware to the Kronos. Krome uses a Korg proprietary tone generator IC (TGL) to synthesize music. The TGL operates at a relatively low clock speed and does not require a heatsink or fan. The size and weight of the TGL are nearly negligible when compared with the mini-ITX motherboard. The Kronos x86 mini-ITX system has a big footprint (6.7in by 6.7in or 170mm by 170mm), needs a heatsink and fan, and weighs 0.61 kilograms (1.4 pounds). The heat generated by the motherboard (20 to 25 watts) must be externally ventilated, thereby complicating the mechanical design of the overall product. Thus, x86 motherboard synthesis comes with a significant system cost. The Intel chipset dissipates the most heat, so even if the extraneous motherboard components are eliminated, thermal design is a significant disadvantage of x86-based synthesis.

Here’s how the complete products stack up (61 key models):

                                    Krome    Kronos 2
                               ----------  ----------
    Synthesis                       EDS-X        HD-1
    Polyphony                      120/60         140
    Power consumption (Watts)          13          60
    Weight (pounds)                  15.9        31.5
    Weight (kilograms)                7.2        14.3

Performance is compared on the basis of sample-based synthesis while disregarding differences in tone quality. The Krome implements only sample-based synthesis, so the basis for comparison on this dimension is limited. As a complete system, the Kronos out-weighs and out-dissipates the Krome two-to-one.

Finally, here are a few words comparing Kronos SSD versus Krome Micro SD for sample storage and transfer. The Kronos SSD is SATA2 with a raw 3Gbit/sec transfer rate. Although the maximum transfer rate is 300MBytes/sec, the 30 GB Toshiba SSD (THNSNB030GBSJ) is specified at:

    Read transfer rate:  180MBytes/sec
    Write transfer rate:  50MBytes/sec

The Class 10 micro SD card is specified at:

    Read transfer rate:   10MBytes/sec
    Write transfer rate:  10MBytes/sec

According to the SD Association, these are minimum speeds and actual devices may operate faster. Further, two different SD bus speeds are rated: 12.5 MB/sec default speed and 25 MB/sec high speed. Without further testing or knowledge of the particular SD card in use, no further conclusions can be drawn properly. One should note, however, that Krome device-to-tone generator bandwidth is significantly lower than Kronos even when best SD performance is assumed.

SD device communication is simpler than SATA. SD is designed for low cost. An SD card interface is a frequent, integrated feature of an ARM SOC. The SD interface favors lower system cost and complexity.

SSD storage devices, on the other hand, are not simple devices. They contain a SATA bus controller, RAM cache and cache controller. Data caching gives SSD its speed advantage over naked flash memory. The SATA interface is part of the Intel NM10 Express Chipset IC on the Intel motherboard. Comparatively speaking, the SD card and bus win on the basis of cost and simplicity.

The complexity of the SATA interface would tend to preclude direct communication from SATA to a proprietary tone generator like the TGL. Cost and simplicity favor “raw” communication between tone generator ICs and RAM/ROM.

Whew! That’s quite a lot of detailed information. To keep things short and focused, I’ll address the suitability of x86 for conventional synthesizer design in another post.

Here is a link to my dive into some old Roland gear. You might also want to read my post about Yamaha MOX internal architecture. There are also three posts (here, here and here) about Yamaha arranger internals.

TC-Helicon Play Electric

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Sometimes the best inexpensive multi-effect stomp box is pitched as a vocal harmony processor.

The built-in effects on the Korg Triton Taktile (TT) are rather plain and unpronounced. So, I cast the net for stomp boxes to beef up the keyboard sounds with reverb, chorus, phaser, flanger, tremolo and the rest of the usual suspects. Something to spice up the guitar sounds is also nice. Vocal harmony processing never entered my mind since I rarely sing.

My first thought was to build a small pedal board of stomp boxes. Based on Internet reviews, I bought a TC-Electronic Hall of Fame (HOF) Reverb pedal. It’s stereo, clean and the preset algorithms are terrific. I love this little red box! Its Toneprint capability is really a gas. Through Toneprint, you can actually add chorus or flanger, making it a good, small, one pedal solution for keyboard effects. I also use the HOF for recording — the algorithms and cleanliness are that good.

Based on that success, my next thought was to add more TC-Electric pedals. TC’s guitar pedals hit the street in the $100 to $150 (USD) range. Thus, you can run up a bill pretty fast covering all of the bases!

Enter the TC-Helicon Play Electric (PE). After finding a very attractive price for the PE at ProAudioStar, I investigated its capabilities. Thanks to smart signal routing, the PE is really like two multi-effect processors in one — one side is a guitar chain and the other side is vocal harmony and effects processing. I’m going to concentrate on the guitar side here as I haven’t explored the vocal harmony processing yet.

The guitar effects chain consists of amp simulation, compression, modulation, delay and reverb. It covers all of the major effect food groups except phaser. What it does cover, it does very well. There are a small number of “greatest hit” algorithms from the Corona Chorus, Vortex Flanger and the HOF — all very usable. The user interface is a breeze and I quickly pulled together presets for chorus, flange, rotor, pan, tremolo and auto filter. The Triton Taktile electric pianos sound great through the PE effects. Thanks to the factory presets, U2 can sound like The Edge (pun intended). The rather lame electric guitars sound huge through the PE presets.

The quality of the rotor effect is a real surpise. Although the Neo Instruments Ventilator doesn’t have anything to fear, the rotor is not bad and it compensates for the TT’s inability to switch between slow and fast rotor speed. (If you can stand the sometimes maddening swirl of rotor-on-rotor violence.) I programmed slow and fast rotor presets in adjacent locations and can switch between fast and slow via the increment and decrement switches on the pedal.

What does the Play Electric give up in favor of lower cost? The individual pedal approach has the advantage of immediacy — lots of knobs and switches to play with. The PE effects are easily tweaked through the UI, but lack the immediacy of front panel knobs. Further, the PE exposes only the most important parameters through the UI, emphasizing convenience over tweaking. The compressor parameters roll up the whole lot of attack, release, etc. into “Amount” and “Makeup” parameters. TC-Helicon offer deeper editing in the much more expensive (and heavier) Voice Live. The Voice Live also has a wider range of effects. From what I’ve heard so far, however, I’m good with the Play Electric.

I look forward to trying the vocal side. The PE does not have MIDI IN for scale detection — it’s all audio, baby. The PE has built-in microphones and will detect scale out of the sonic ether as well as processing the audio signal at the guitar input. I’ll post results after experimenting.

The TC-Helicon Play Electric is normally advertised in the live sound section of on-line and print catalogs. Thus, it’s worth checking out vocal processors when looking for keyboard/guitar effects. You might be surprised at what you’ll find.

There is one alternative to the PE that looks viable for keyboard players. Keyboardists don’t usually chain effects together like a guitar player and often one additional effect through a reverb will do. The Line 6 M5 pedal is the “Swiss Army Knife” of effects. It does one effect at a time and has a very wide range of available effects (much greater than the PE). The M5 has stereo inputs (while the PE is mono). An M5 coupled with the HOF would be a capable duo at a reasonable total cost.

Switching gears a little bit, I don’t know why Keyboard Magazine and other keyboard-oriented publications don’t review effect pedals very often. These pedals are just as vital and useful to keyboard players as they are to guitarists. The Keyboard Magazine guys need to drop by the Guitar Player offices while they are writing their massive annual pedal round-up.

Whither XG?

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Once upon a time, the hardware tone module was king of “desktop music production.” A wide range of options were available from pro-level tone modules to desktop tone generators to ISA/PCI cards. The General MIDI (GM) standard came about in this era because people wanted to have consistent playback across hardware platforms.

Every manufacturer offered one or more modules. Two players — Roland and Yamaha — jumped in big. Each company offered desktop tone modules adhering to their own semi-proprietary extensions of the General MIDI standard. Roland had its GS while Yamaha had its XG.

Then, software plug-ins killed the tone module.

Native, computer-based signal processing became fast enough that hardware tone generation was no longer required.

Roland GS, meanwhile, has gone on relatively hard times. Today, Roland offers two products that are up-front GS: Mobile Studio Canvas and Sound Canvas for iOS. The Mobile Studio Canvas is a pricey little number that streets out at $429 USD. Not exactly cheap. Sound Canvas for iOS is an iOS app supporting Inter-App Audio and Audiobus. Roland claim that the app and its host can act as a tone module through a suitable Core MIDI compatible interface. Mobile Studio Canvas is $19.99 through the Apple App Store.

The Virtual Sound Canvas was a VST- and DXi-compatible, multi-timbral soft synth. Unfortunately, for desktop users, the Roland Virtual Sound Canvas (VSC-MP1) was discontinued.

Yamaha XG is battered, but is still breathing. XG-based hardware tone modules are nearly extinct. (Check ebay…) However, current arrangers from Yamaha offers XG compatibility, even if it’s only the XGlite subset. In fact, XG is the de facto voice architecture on arranger keyboards. Edit a voice on an arranger and you are tweaking XG parameters. Of course, this means that you must have space for an arranger on your desktop. A half-rack 1U tone module is far more compact and desktop-friendly.

“Pro” keyboardists still turn up their noses at GS, XG and arrangers. A large part of this is guilt by association with General MIDI. Beneath it all in Yamaha-land, the synths and the arrangers share hardware technology such as CPUs and tone generation circuits. XG is essentially a wrapper around pro-level samples and tone generation.

XG also lives at the heart of the Yamaha Mobile Music Sequencer (MMS) app. MMS has a software-based XG engine inside. It supports 9 reverb, 4 chorus and 26 variation effects. Yamaha cut down the XGlite sound set to just 42 GM voices plus 42 or so synth voices. In case you’re interested, I’ve documented many of the XG features in MMS here:

Mobile Music Sequencer Reference
Make music with MMS on PSR/TYROS

MMS demonstrates that it’s possible to host XG on an iPad with an ARM processor. Will Yamaha answer Roland’s Sound Canvas for iOS?

Needing an XG-compatible VST soft synth on Windows, I went in search of one and stumbled onto a retro cult. Turns out, there are a whole lot of other people who would like an XG-compatible VSTi on Windows, too.

First, there are enthusiasts who are trying to resurrect the S-YXG50 soft synthesizer on Windows 7 (and earlier). The S-YXG50 uses either a 2MByte or 4MByte wave table, so we’re not talking stellar sound quality. I experimented with S-YXG50 on Windows 7 with no success.

Then, there are enthusiasts who take old daughter boards (DB50XG or DB60XG) and fashion standalone tone modules from them. (Just add a power supply and a MIDI interface.) These daughter boards have a 4MByte wave table. Like XG tone modules, XG daughter boards are scarce as hen’s teeth.

The issue that always rears its head with this old tech is the availability of drivers. You can find the occasional Yamaha-based sound card or SW1000XG, but driver support usually stops with Windows XP (at best).

Finally, another sub-cult has discovered the joys of Yamaha MidRadio. MidRadio is a MIDI player application for Windows 8 (and earlier). It is XGlite compatible with 361 regular voices, 10 drum kits and 2 SFX kits. A few of the regular voices are so-called “panel voices” in the PSR E-series — an added bonus! Wave table size is about 11MBytes. And, guess what? It sounds pretty darned good. Here are links to the list of voices and effects in MidRadio version 7:

List of MidRadio voices and effects

If you try MidRadio, be prepared to use Google translate and be prepared to wade through a Japanese-only user interface.

A few intrepid souls discovered that the MidRadio sound engine (SGP2.DLL) is just a few bricks short of being a VST software instrument (VSTi). They developed a patch which turns the DLL into a VSTi. Yes, the patch works and I can send XG-compliant MIDI from Steinberg Cubase, Ableton Live and VSTHost to SGP2. It plays rather nicely.

In general, I do not recommend this approach. Anytime you download a patch from the Web and execute it, you put the privacy and security of your computer and its information at risk.

Given this enormous red flag, I wish that Yamaha would sell an XG-compatible VSTi for Windows and Mac. There are users waiting for properly a supported, street legal XG plug-in soft synth at a reasonable price. And certainly, we wouldn’t turn down a free one.