About pj

Now (mostly) retired, I'm pursing electronics and computing just for the fun of it! I'm a computer scientist and engineer who has worked for AMD, Hewlett Packard and Siemens. I also taught hardware and software development at Case Western Reserve University, Tufts University and Princeton. Hopefully, you will find the information on this site to be helpful. Educators and students are particularly welcome!

In the house: V3 Sound YAMMEX XXL

Posted on November 2, 2022 by pj

Thought I would post a quick note about the new unit under test — the V3 Sound YAMMEX XXL tone module. The YAMMEX is a member of the V3 Sound XXL family of tone modules. They all share the same triangular shape and are light as a feather:

V3 Sound YAMMEX XXL expansion tone module

The lump-in-the-middle power supply is roughly the same weight!

You might have seen and heard Piano Man Chuck demonstrate the V3 Sound Grand Piano XXL module. [Piano Man Chuck is a V3 Sound dealer, BTW.] Well, the YAMMEX has the same sound set as the Grand Piano XXL. The main differences are:

The MIDI bank and program change layouts are different: Grand Piano XXL for general use as an expander, YAMMEX XXL as a Genos/PSR expander.
Grand Piano XXL is supported by the V3 Sound Control app; the YAMMEX XXL is not.
Grand Piano XXL is supported by two different MIDI Designer templates; the YAMMEX is not.
YAMMEX XXL voices are selected using custom Genos/PSR user voices.

YAMMEX XXL arrives from the factory with a USB flash drive containing the custom user voices (VCE files) needed to select voices through Genos/PSR. It’s all described in the YAMMEX XXL manual. [Henceforth, “Yammex” means “YAMMEX XXL”.]

I found a Yammex on ebay at a price that was impossible to refuse. It would be a shame to confine Yammex to Genos duty alone, so I studied the heck out of its MIDI implementation. I also examined the VCE files available from the V3 Sound Web site. Hmmm, looks like it’s a simple matter of uttering the appropriate Bank Select MSB, Bank Select LSB and Program Change messages. We can do that!

An inquiry to V3 Sound about compatibility was answered quickly, but implied that Yammex was only for Genos/MIDI. If you know MIDI and your controller’s capabilities, and if you don’t mind a little work, Yammex definitely can do more than Genos/PSR.

I was sorely tempted by the V3 Sound XXL series because it is based on the Dream S.A.S. SAM5716B synthesis chip. After hearing the SAM2635 and its GM/GS sound set, I wanted to hear what a high-end Dream chip could do with 3GBytes of professionally produced instrument samples. Cut to the chase, V3 Sound do not disappoint especially at the price I paid.

The box arrives. I open the shipping carton and what the? The Yammex box is in fine shape, but is covered in round “Demo” labels. I instantly smell “Sweetwater”. And there’s candy, and a Sweetwater “Thank You” card. The ebay seller is Jeff’s Music Gear. After a Google, I discover that Jeff’s Music Gear is Sweetwater’s ebay consignment shop! Nice to know that I was in good hands all along.

OK, then, plug everything up using Yamaha MODX as a controller. (See my article about Yamaha MODX Zone Master.) Ooops, no flashing MIDI light and no sound. I’m already composing a message to Jeff’s when I remember this note in the Yammex manual:

No sound? The YAMMEX XXL sound expander only creates a tone when you call up a sound from the V3 folder in your keyboard’s display. Just connecting it to your keyboard is not enough.

They aren’t kidding! I select a voice through the MODX Zone Master screen and suddenly the MIDI light starts flashing and Yammex starts talking. Delete the message to Jeff’s.

One other note from the manual is helpful during bring up:

Testing MIDI connections and settings. After connecting your MIDI cable and making sure your MIDI settings are correct, select a V3 User Voice. The MIDI LED on the YAMMEX XXL should now blink with every keystroke.

I find this behavior to be a dubious design decision. The purpose of a MIDI light is to indicate MIDI reception under any condition. While troubleshooting, I connected the Yammex THRU port to MIDI-OX on a PC and verified MIDI operation. Most of V3 customers will not be that savvy…

I’ve just begun auditioning sounds and already I’m pleased. I like and prefer the Bösendorfer Imperial 290 (Vienna) over the Steinway Model D (Hamburg). I fell in love with Bösendorfer when I first touched one in 1980. The electric pianos are good although too clean and polite. The organ samples are damned good. There are two flavors: No Leslie and Leslie sampled in. Sans-Leslie voices are meant to be dirtied up by an external pedal. I’ll try the Electro-Harmonix Lester K for spin and throw some overdrive on the EPs, too.

I like the Oberheim pads — another love. The classical strings are solid. That’s as far as I’ve gotten into the sound set. I’m looking forward to hearing the rest.

As to the supplied USB flash drive, the previous customer zorched the factory VCE files. I found an X6A file instead which I recognize as a Yamaha MOXF dump file. I guess the previous customer tried Yammex with MOXF and was disappointed. Fortunately, V3 Sound provide the Genos/PSR VCE files on their Web site. The supplied drive is only 64MB. [Not really a complaint.]

Experiments to come? Once I get my faves down to 8, 16 voices or so, I’ll configure the Arturia Keylab Essential. The extra knobs and sliders will come in handy. Also, I will whip up a simplified MIDI Designer template for the Yammex. The existing templates are comprehensive — yet overwhelming. I’m thinking about a UI similar to Korg Module. Those Korg folks are definitely on to something. Simplicity is king. MIDI Designer (with StreamByter) on iPad should give me splits and layers — maybe even a wireless Bluetooth interface to Yammex? Finally, Dream multi-FX.

Review: Korg Module General 128

Posted on October 27, 2022 by pj

Korg have released a new expansion pack for Korg Module — General 128.

General 128 is one of those expansions where you say “Why didn’t they release this on Day One?” Essentially, General 128 is a 108MB General MIDI sound set minus drums.

Most of us will not sequence MIDI tunes using Korg Module. However, General 128 covers all of the bases, making Korg Module generally useful in a flash. As GM sound sets go, all of the voices are reasonably pleasant and usable enough.

The only real knock on voice quality is their rather plain sonics. The effect programming is very ordinary. Once suitably dressed, individual voices are brought to life. For example, throw a little tremolo on that electric piano. Having a small memory footprint, one shouldn’t expect many (any?) velocity-switched multi-samples. To my ears, most of the voices are very “uni-dimensional” single level multi-samples which just get softer or louder with touch.

This isn’t all bad! I stumbled onto Korg’s introductory sale while casting around for new voices to layer within Module. [The introductory sale price, $9.99 USD, is good through Monday, 31 October 2022.] It’s much easier to layer up simple timbres than harmonically rich, dynamic sounds. For example, you wouldn’t use the oboe for an exposed solo, but it does add a reediness to a French horn producing a more WW section-like tone.

Allowing for the sound set limitations (i.e., one velocity layer), my favorite voices are the Acoustic Grand (warm), Electric Piano 1 (What’d I Say), Synth Strings 1 (warm, not too synthetic), French Horn (fanfare-ish), Bassoon (warm double reed), Flute (simple without devolving to Mellotron).

At the introductory price, the General 128 expansion is a no-brainer. In addition to Korg Module, the pack can be used in Korg Gadget Glasgow and as an AUv3 plug-in. General 128 might get me using Korg Gadget — maybe sequence a demo.

Big picture, I’m feeling quite comfortable with my iPad rig these days and I think it’s rehearsal ready. I would use either the Korg Microkey Air or Arturia Keylab Essential 49 depending upon my degree of laziness on any given day.

I tried going wireless with the Arturia Keylab Essential getting good results with the Yamaha MD-BT01 5-pin Bluetooth dongle. Only the MIDI OUT side is connected since the Arturia doesn’t have a 5-pin MIDI IN port. Connects up to Korg Module without problems. I don’t recommend the Yamaha UD-BT01 USB Bluetooth adapter for the Arturia; I get stuck notes.

I’m also getting more confident with the Roland (Boss) Ev-1-WL Bluetooth expression pedal, now that I understand its darned flashing lights and colors.

Yamaha MODX: Zone Master

Posted on October 18, 2022 by pj

If you mix and match your gear over MIDI, you will eventually need to send a program change message. Yesterday, I wanted to audition the sounds in my hacked Akai MPK Mini Play and needed to send a full Bank Select MSB (CC#0), Bank Select LSB (CC#32) and Program Change message sequence to the Akai MPK Mini Play.

Usually I scramble around looking for cables and hook up a MIDI controller like the Arturia Keystep or Keylab Essential. Inevitably, I scratch my head trying to remember how to send a full sequence of bank and program change messages from the controller. Maybe a trip through a PC-based control editor is required. It’s amazing that in this day and age, it is still difficult or impossible to send a full three message sequence in one go! [Grr.]

This time I said “Why not MODX?” and the best solution of all was in front of me.

The trick is to use the MODX Zone Master feature. I don’t intend to deep-dive Zone Master here and recommend the Mastering MONTAGE: Zone Master FAQ on the Yamaha Synth site. The MODX and Montage are enough alike such that the Montage tutorial applies to MODX, too.

The basic concept is simple. When Zone Master is enabled, a part in an MODX Performance can send MIDI messages over the 5-pin MIDI OUT. One needs to configure a few things before setting up a part and zone in a Performance.

For my experiment, I hit the UTILITY button and tapped the MIDI I/O tab under Settings. There, I made two changes:

I changed MIDI IN/OUT to MIDI in order to send MIDI messages through the 5-pin MIDI OUT. If this parameter is USB, you won’t send or see messages on the 5-pin port.
I turned Local Control OFF. If MODX isn’t connected to a powered speaker (or whatever), this step is optional.

Don’t forget to change these settings back to what they were when you’re done. MODX remembers them across power down and you may be surprised to find a silent MODX when you turn it on again.

MODX advanced settings (including Zone Master)

Next, tap the Advanced tab. Turn Zone Master ON. Zone Master is not enabled by default. If you don’t enable Zone Master, you will not see zone-related tabs and parameters when editing the Performance part.

Hit the EXIT button and click CATEGORY. We’re going to create a new, empty Performance. Tap the Init category button. Then tap Init Normal (AWM2). This creates a new empty (AWM2) Performance.

Cursor over to the part and hit the EDIT button. You should see two additional Zone Master tabs that normally aren’t displayed in Part Common Edit (i.e., when Zone Master is disabled). Tap the Zone Settings tab. Make the following changes:

Turn Zone ON.
Set the Transmit Channel to Channel 1 or your heart’s desire.
Turn MIDI Send ON.

Make sure Bank Select and Program Change are enabled (ON). Now you’re ready to send bank and program change messages to the target device. You did connect your target device to the 5-pin MIDI OUT port, right?

For those of you who are building a Performance to be saved and used in the future, check out the Internal Switch (Int SW) parameter. Turn it OFF if you don’t want MODX to send messages to the internal tone generator, that is, make this a locally silent part.

Cursor over to (or tap) the MIDI Bank MSB, MIDI Bank LSB and MIDI Program Number parameters to change values. MODX sends a full three message sequence when the Program Number is changed. So, if you change Bank MSB or LSB, you must send a Program Number to send the full sequence and make the actual patch change in the target device.

MODX bank select and program change example

In the screenshot above, Bank MSB 24, Bank LSB 0, and Program Change 5 selects the 60’s vintage electric piano (Wurli) in the Akai MPK Mini Play tone generator. Oh, you didn’t know the MPK Mini Play had a Wurli variation? Read on, below.

Conveniently, you can send MIDI volume (CC#7) and MIDI pan (CC#10) messages from this same screen. You can mess with local Octave Shift and Transpose. Pitch bend and mod wheel messages go out, too, and you can play away and freely audition sounds in the target device/module.

Overall, I find the MODX Zone Master method an easy way to experiment with a target device or tone module. If you’re a MODX owner, give it a try!

Hacked Akai MPK Mini Play?

In case you missed it, I added 5-pin MIDI to the Akai MPK Mini Play (Mk1) and gained full access to the Dream S.A.S. SAM2635 synthesizer chip within. The mod is fairly simple and relatively risk free as far as mods go. [Please remember that any mod has risk and voids your warranty.]

The MPK Mini Mod is functioning quite well and is stable. Just remember that only one source can send MIDI messages to the SAM2635 at a time, i.e., either the MPK Mini Play host microcomputer or the 5-pin DIN MIDI IN, not both. Messages are not merged and will collide electrically, leaving the SAM2635 confused.

The Dream SAM2635 is a full Roland GS implementation, not just General MIDI. The SAM2635 offers variation sounds including different organs and electric pianos. I really need to write a short run-down and review…

MODX screen capture

Just in case you’ve forgotten the steps to capture a MODX screen, here they are:

Insert A USB flash drive into the USB To DEVICE port on the back panel.
Press and hold the A/D INPUT ON/OFF button.
Press and release the AUDITION button.
Release the A/D INPUT ON/OFF button.

Simple, eh? And so easy to forget. 🙂 The screen shots are written to the USB flash drive in PNG files.

BTW, according to my web stats, my MODX split/layer tutorial remains popular. Take a look if you’re still puzzled about splits and layers. I also have a simple MODX Super Knob example.

“P” is for “piano”: Yamaha P-S500 digital piano

Posted on October 8, 2022 by pj

While we’re distracted with “CK”, “AN”, and whatnot, Yamaha sneaks out a new P-series digital piano in Europe: the Yamaha P-S500.

Natch, you can read all about the P-S500 at Yamaha’s European web site. Physically, it’s a minimalist slab that’s designed primarily for the home or small studio market segments. Cost is about 2,100 Euro and I would expect it to retail for about $2000 USD in the States.

Basic features [courtesy of Yamaha] are:

Compatible with Smart Pianist app installed to a smart device
Stream Lights feature helps you perform even if you can’t read music notation
Enjoy playing along with the 403 preset Songs, covering a wide range of genres from pop music to classical music
Audio To Score function converts your favorite audio songs into piano accompaniment scores
Authentic Yamaha CFX & Bösendorfer Imperial concert grand piano Voices
Virtual Resonance Modeling (VRM)
88-note weighted GHS keyboard
Huge variety of 660 high-quality instrument Voices, including Super Articulation Voices
Built-in Auto Accompaniment features with 370 Styles
Microphone input and automatic Vocal Harmony

Auto-accompaniment, styles, Super Articulation voices? We’ve seen these features in the DGX series, notably, the most recent DGX-670 model. The table below compares the P-S500 against the DGX-670. The DGX-670, by the way, goes for considerably less dough: $850 USD.

                DGX-670           P-S500 
                ----------------- --------------------------------- 
Main piano:     Yamaha CFX        CFX, Bösendorfer Imperial 
VRM:            Yes               Yes 
Key-off sound:  Yes               Yes 
Action:         GHS               GHS 
Piano Room:     Yes               Yes 
PB wheel:       Yes               No 
Dual/layer:     Yes               Yes 
Split:          Yes               Yes 
USB audio:      Play/record       Play/record 
Bluetooth:      Yes               Not built-in (optional)
Amplification:  2 x 6W            2 x (20W + 6W) 
Speakers:       2 x (12cm + 5cm)  2 x (12cm x 6cm oval+2.5cm dome)
Display:        480x272 color     80x16 mono LCD 
Weight          47.2 pounds       48.1 pounds

Here’s the decoder ring for Yamaha acronyms: Virtual Resonance Modeling (VRM), Graded Hammer Standard (GHS), Super Articulation (SA), Cool (velocity switched), Live (stereo), Organ Flute (drawbar organ).

The P-S500 looks to be the upscale, uptown sibling of the DGX-670. At 48 pounds, I don’t think you’ll want to schlep the P-S500 out of the house very often. In terms of styles and voices, the P-S500 is superior:

                          DGX-670  P-S500 
                          -------  ------ 
Total voices              601      660     
    VRM voices            9        13     
    SA voices             49       111     
    Natural voices        11       25     
    Sweet voices          26       27     
    Cool voices           53       47     
    Live voices           68       58     
    Organ Flute voices    0        29 
Total styles              263      370     
    Pro styles            215      328     
    Session styles        19       25     
    Free Play styles      0        3     
    Pianist styles        29       13 
Drum Kits                 29       29

The P-S500 factory voice set includes many of my favorites. If you’re looking for a more than decent, mid-level keyboard with auto-accompaniment and a graded hammer keyboard, the P-S500 is worth a look. Versus a mid-level arranger keyboard, you’re still giving up a pitch bend wheel, multi-pads, style control buttons, MIDI record/edit, etc. If you just want to play and have a good piano experience, I’d go with the P-S500 in a heartbeat. (The DGX-670 is no slouch, either.)

There are many other differences that I’ve glossed over. So, if you’re trying to decide between DGX-670, an arranger or the P-S500, be sure to dig into the manuals and data list files. Yamaha doesn’t always make it easy to compare, especially as to your specific musical goals and use cases.

One enormous difference needs to be emphasized, however. The P-S500 front panel is utterly minimalist. If you want to exploit the P-S500 to its fullest, you must use the P-S500 with the Yamaha Smart Pianist app on a tablet (Apple or Android). In this respect, the P-S500 is more like the CSP series of digital pianos for the home. It’s like a CSP without the furniture. The CSP models have enhanced GH3X or NWX keybeds which improve the piano playing experience. Given that the Smart Pianist is almost a necessity, it’s kind of weird (cheap) to omit built-in Bluetooth.

Yamaha are certainly giving us choices!

A final, electronics nerd comment. While studying the internal design of current arranger, synth and digital piano products, the designs often seem like a deconstructed tablet connected to a keybed, tone generator and MIDI/USB interface. The digital electronics are remarkably similar. With the P-S500 and the CSP series, it’s like Yamaha said “Aw, the heck with it” and moved functionality out of the piano (arranger, synth) chassis into a stock, commercial tablet like iPad or Google Pixel tablet. I don’t think we have seen the end of this approach to instrument design…

Other reviews and comments about digital pianos:

Out Of The Shadows

Posted on October 3, 2022 by pj

I’ve been working on backing and lead instruments for the classic Del Shannon song “Keep Searchin'”.

Yamaha Genos™ is made for this tune. First off, its “ShadowedPop” style is the perfect fit for that old 1950s rock’n’roll vibe. It has just the right amount of swing and attitude.

Next, Genos has very good electric guitars for lead. Want clean Tele or Strat? Genos has them. Genos also has a suite of effects to obtain a complete, authentic guitar tone.

Yamaha arranger styles have “One Touch Settings” which are mini-registrations. Hit an OTS button and Genos will both change song section and bring up an appropriate voice. The Genos “ShadowedPop” style has two OTS mini-registrations that are worth deconstructing to see how the Yamaha sound designers got their Shadows guitar tone: “60sShadowLead” and “ShadowedGuitar”.

Of course, the “shadow” in all of these voice and style names refer to Hank Marvin and The Shadows — one of, or perhaps, THE iconic 1950’s guitar band and sound. The Shadows’ treatment felt absolutely right for the Del Shannon cover. Hank Marvin was perhaps the first English artist to pick up a Fender Strat, usually putting it through a Vox amp.

The PSR “ShadowedGuitar” voice goes back four or five years and is a standard factory preset. If your Yamaha arranger does not have “ShadowedGuitar”, choose a clean, 1960’s vintage guitar preset voice. Change the insert effect to Tempo Echo and set the insert effect send level to 30. Change the effect parameters to:

 Param#  Parameter name       Value 
 ------  -------------------  ------ 
      1  Delay Time           8th 
      2  Feedback Level       +28 
      3  Feedback High Damp   1.0 
      4  L/R Diffusion        +14ms 
      5  Lag                  0ms 
     10  Dry/Wet              D34>W 
     13  EQ Low Frequency     500Hz 
     14  EQ Low Gain          0dB 
     15  EQ High Frequency    4.0kHz 
     16  EQ High Gain         0dB

Reverb is a big part of the 50’s vibe and you’ll need gobs of it on the guitar. Select a hall reverb and set the reverb send level to at least 50. If your arranger has it, I recommend the “Real Medium Hall+” preset. It’s one of Yamaha’s best reverbs, in my opinion.

Only Genos has the “60sShadowLead” voice voice. Fortunately, it’s easy to add a close sound-alike to your instrument. Start with “ShadowedGuitar” or a clean, 1960’s vintage guitar preset. Get into the mixer (or DSP effect page) and change the insert effect to Multi FX Vintage Echo and set the insert effect send level to 127 (if necessary). Then change the effect parameters to:

 Param#  Parameter name       Value 
 ------  -------------------  ------ 
      1  Comp Sustain    2.9 
      2  Wah Switch      Off 
      3  Wah Pedal       0 
      4  Dist Switch     Clean 
      5  Dist Drive      5.0 
      6  Dist EQ         Mid Boost 
      7  Dist Tone       3.5 
      8  Dist Presence   4.3 
      9  Output          110 
     11  Speaker Type    Twin 
     12  LFO Speed       2.103Hz 
     13  Phaser Switch   Off 
     14  Delay Switch    Delay St 
     15  Delay Control   60 
     16  Delay Time      33

We met the Multi FX algorithm once before. This algorithm is like a virtual guitar pedal board:

Compressor -->  Wah --> Distortion --> Phaser --> Delay --> Spkr Sim

The above parameter values dial in The Shadows’ guitar tone.

You’ll need gobs of reverb, again, to complete the scene. Choose the “Real Medium Hall+” preset and set the reverb send to at least 40.

The “60sShadowLead” OTS also configures the chorus system effect. Having listened to the overall tone with and without chorus, this step is optional. (Possibly some other style part may be affected by this change or a change to any other system-level effect including reverb.) Change the chorus type to “Celeste 1” and set the chorus send level to 12. 12 is not especially high, so you can see why this last step is optional; it’s just a little sweetener.

You might consider changing the chorus effect to tremolo (e.g., “E-Piano Tremolo”). Guitarists in the 50s and 60s didn’t have guitar pedals. (Sorry, Edge.) So, folks relied on guitar amp spring reverb and tremolo (often mislabeled “vibrato”) to get space-y effects. I still have the sound of an Ampeg Gemini going through my head. 😎

Select the “E-Piano Tremolo” effect preset, increase the AM Depth to max, and set the chorus send level to 127:

 Param#  Parameter name       Value 
 ------  -------------------  ------ 
      1  LFO Frequency        5.38Hz 
      2  AM Depth             127 
      3  PM Depth             0 
      6  EQ Low Frequency     500Hz 
      7  EQ Low Gain          0dB 
      8  EQ High Frequency    4.0kHz 
      9  EQ High Gain         0dB 
     11  EQ Mid Frequency     2.0kHz 
     12  EQ Mid Gain          0.0dB 
     13  EQ Mid Width         1.0 
     14  LFO Phase Difference +39deg 
     15  Input Mode           Mono 
         Return Level         127

You’re looking for that deep, “Spaghetti Western”, Ennio Morricone effect. Play the lead line an octave down. Have fun!

The EQ parameters in the tremolo algorithm make this a good guitar tone mangler — swept mid EQ with Q (width)! Mid boost or cut is right at hand.

Here are short demos (MP3) on Genos with tremolo and without tremolo. Yamaha Montage and MODX have the same effect algorithms, so you should be able to apply the same techniques on those instruments, too.

Links to a few other posts about chasing tone on Yamaha gear:

Mid-September new products

Posted on September 15, 2022 by pj

Korg dropped two new products for Fall 2022: The Liano digital piano and drumlogue hybrid drum machine

The Liano is about as minimalist as it comes. The Liano is a sleek monolith with just a few simple controls. This keyboard absolutely does not require a user manual! You get the standard eight preset voices (two grands, a Rhodes, an FM EP, harpsichord, pipe organ, electric organ, strings), two effects (reverb and chorus), metronome, two built-in 8cm bass reflex speakers (8 Watts a side), USB-B, and sustain. That’s it.

This board is such a slab, Kubrick could have used it as the monolith in 2001: A Space Odyssey. 🙂 Imagine monkeys dancing around a Liano tipped on its side. You know, Korg, every search engine in the world will auto-correct “liano” to “piano”?

The Liano is super-light 6.0kg (13.2 pounds). The demos sound pretty decent. Aside from being a student piano, I could see using a Liano at choir rehearsals or any occasion requiring portability (six AA batteries). The down-side of the small sound set is that a given preset either fits the musical situation or it doesn’t. This is especially true of the pipe organ (uni-dimensional full pipes) or the electric organ. I hate to slag the Liano’s electric organ as it would be fine in a jazz setting, but forget rock or gospel.

Korg clearly are going head-to-head with Yamaha and Casio in the entry-level piano market. Liano’s minimum advertised price (MAP) is $399 USD.

I’m sure the Interwebs will be filled with drumlogue news. It’s analog! The Korg demos have punch! It accepts ‘logue synth plug-ins! It’s $599 USD MAP.

Both the Liano and drumlogue are pre-order. I hope Korg gets a move on because I an still waiting for the Korg Nu:tekt NTS-2 oscilloscope ($230 USD MAP). Come on, man!

Not from Korg, the Intech Studio Knot is another USB host to MIDI bridge box (AKA stand-alone USB MIDI host). It is tiny and has an $89 pre-order price. (That’s 25% off.) Knot takes power from either USB-C or a DC adapter. External power is critical because some controllers draw enough current to power a small town. (Well, that’s exaggerating.)

The down-side of its tiny size is 3.5mm MIDI IN and OUT ports instead of 5-pin DIN. Yes, you will need 3.5mm to DIN adapters.

Knot is an open source project and supports firmware updates.

If you need a MIDI bridge and have a Raspberry Pi, check out these articles:

All it takes are a few simple Linux commands. Admittedly, a dedicated bridge like the Knot is the better option for gigging.

What if CS and SK had a baby?

Posted on September 12, 2022 by pj

Got a PM from Jan, a long-time reader. Jan found a page on YamahaSynth about the Yamaha MX product line. The page features the phrase “CK — Classic Keyboards”. CK?

I suspect that CK61™ and CK88™ refer to a new line of keyboards, not a refresh of the MX series. I have to agree that the MX product line is in serious need of a refresh; It is based on the geriatric Yamaha Motif XS sound set.

Still, Jan’s comments got me thinking, especially about the early history of Yamaha synths.

The earliest Yamaha synths — SY-1 and SY-2 — Appeared in the mid-1970s. These 3-octave beasts provided a range of factory presets like trumpet, clarinet, guitar, piano, etc. and a small handful of sliders and knobs on a panel to the left of the keybed.

The SY-1 and SY-2 were quickly superceded by the more popular CS series. The CS series had monophonic and polyphonic models covering the range from the highly portable CS-01, through the Concertmate-like CS-5, to the revered altar of synthesis, the CS-80. The CS synths appeared in the late-70s and early-80s.

The Yamaha SK series appeared in roughly the same time-frame and were somewhat eclipsed by the CS synths. I remember playing both CS and SK keyboards in Salt Lake City, wearing out my welcome at local music shops around town. 🙂

Like the beefier end of the CS line, the SK keyboards sported beautiful — and heavy — wooden end-cheeks and cases. Yamaha have always found a way to spotlight their expertise in woodworking!

Sonically, the SK series are an extension of digital organ technology. The SK-30, for example, had three independent sound generators: organ, poly synth and solo synth. The organ has footage tab stops and percussion. The poly synth is split into two subsections: string and poly synth. Each section is 7-note paraphonic. The monophonic solo synth consists of a VCO feeding a wave-shaper that sends a sawtooth or pulse into the VCF and VCA stages. The organ and poly synth sections each have their own timbre shaping circuitry akin to the tone shaping one finds in organ designs of the era.

Why two concurrent product lines, both ostensibly synthesizers? Engineers were fighting analog VCO pitch stability at that time. The SK series had better pitch stability overall than the CS series and offered polyphony to boot. Who knew that analog would be more popular than digital?

So, what if the CS series and the SK series had a baby? “C” from the “CS” series plus “K” from the “SK” series equals “CK”. Yamaha have been known to dip from their historic well for naming. Perhaps the new CK series are a poly/mono hybrid? Just guessing!

TMI

Looking at the service manuals for this old tech is a blast down memory lane. The SK series use several Yamaha proprietary chips from their electronic organ and CS synthesizer product lines.

A number of on-line resources claim that the poly-synth tone generators use FM synthesis. This is incorrect. Specifically, the poly-synth uses YM70400 GOA integrated circuits (IC) based on Yamaha’s Pulse Analog Synthesis System (PASS). The YM70400 (and the other tone generators) receive a serial 4-bit key code from a key scanner/assigner IC. The key codes tell the tone generator(s) which notes to produce and trigger. The SK-30 has dual poly-synth generators which are each 7-note polyphonic, producing 8’/16′ square waves and 4′ sawtooth waves. Each side is routed through analog filters tailored for strings on one side and an EG-controlled VCF on the poly synth side.

The SK-30 organ section consists of a YM62200 top-octave tone generator (TGC) and two YM70200 organ generators, GF1 and GF2. The organ section is 7-note polyphonic. GF1 and GF2 generate sine waves which are sent through the drawbar tabs for mixing and filtering. GF1 and GF2 support all common organ footages and percussion.

All three sections can take advantage of a tremolo/ensemble effect and/or a multi-pin Leslie connector. The effect is a bucket brigade device (BBD) delay/vibrato generator. [The term “Tremolo” is abused here.]

Much is described in the excellent article “Yamaha Symphonic Ensemble SK20”, Electronics & Music Maker, March 1981. Back in the day, electronic music magazines occasionally gave a detailed glimpse inside — sadly lacking in today’s review articles. sandsoftwaresound.net tries to fill that void.

Akai MPK Mini beauty products

Posted on September 7, 2022 by pj

Well, at first, I was going to strip it for parts. Then I changed my mind.

My original plan was to mod and customize an Akai MPK Mini Play (Mk1), making it a stand-alone synthesizer. As to cosmetics, I wanted to jazz it up with colorful knobs and a reverse white-on-black keybed. I would either find replacement keys or I would buy an Akai MPK Mini White Edition (Mk2), bust it down, and swap in the white-on-black keybed.

Hopes were dashed when I discovered the limitations of the MPK Mini Play’s implementation. Akai’s firmware blocks full access to the Dream S.A.S. SAM2635 synthesizer. I made a MIDI IN/OUT mod, letting me communicate with the Dream through 5-pin DIN MIDI. My original goal of a stand-alone synth, though, went down the tubes.

While the mod was playing out, I bought an Akai MPK Mini White Edition (Mk2) on ebay, ostensibly, for parts. BTW, if you’re looking for an MPK Mini, there are scads of them available on ebay for much less than retail. [If you’re OK with used.]

Gratefully, the previous owner had not registered the MPK Mini and I was able to download Akai’s software bundle. I installed MPC Beats — Akai’s MPC-style DAW — and the five expansion packs included in the bundle. I gave MPC Beats a try. Lo and behold, it was a lot of fun! I found the MPK Mini to be a better companion for MPC Beats than the MPK Mini Play. Suddenly, all desire to strip the White Edition was lost.

Now I want to keep using the MPK Mini (Mk2) as an MPC Beats controller and treat the MPK Mini Play as a MIDI module. Time to beautify the White Edition. [Spared from the chopping block.]

As to appearance and use, my one major quibble is the short, skirted knobs on both the MPK Mini and MPK Mini Play. I find these knobs hard to grab — more appropriate for small hands than my mitts.

Adafruit knobs versus original Akai MPK Mini knobs

Short knobs mean short pot shafts. Due to the short potentiometer shafts and the front panel recess around the pots, any old knob will not due. Casting around on the Web, I found two candidate knobs at Adafruit:

Adafruit #5093 Slim rubber rotary encoder knob, 11.5mm by 14.5mm D-shaft
Adafruit #5532 Red micro potentiometer knob (4 pack)

The red knobs are part of a multi-colored family. If red isn’t your fancy, try blue, black, white, cream, green, etc. Individually, both knob types are about $.70 USD per knob — not bad. Adafruit’s shipping is a tad high (one pound weight minimum charge) and you should look around for a few other things to buy in the same order. If you’re thinking about a 5-pin MIDI mod, I suggest the Adafruit MIDI FeatherWing Kit.

First up, is the Adafruit #5093. These knobs are only available in black. They are rubber and have a very nice feel. They only fit D-shaft potentiometers (or encoders) and are not appropriate for knurled or round shafts. The rubber knobs just barely cover the panel holes, but should keep out dust.

Akai knobs (left) versus Adafruit rubber knobs (right)

The pointers are well-placed and hit the min and max positions exactly. The rubber knobs are twice as tall as the factory knobs and are easy to grab. They are just snug enough on the pot shaft and can be removed without much force. I like these knobs and recommend them. Buy ten and get a price break.

I tried a few different Yamaha knobs on the MPK Minis. Forget it. The pointers don’t align with the min and max positions. Avoid knobs where the inner opening or set screw is too high above the bottom. Such knobs will float above the darned short Akai shafts.

Next up, is the Adafruit micro pot knob family. I bought red, black, blue, white and cream. The cream knobs look especially handsome. Unfortunately, cream clashes with the White Edition. Better to go with bright white (which match the sharp keys) or best to go full contrast and a splash of color, red.

The micro pot knobs have a very small set screw. Adafruit recommend a 2mm hex wrench, but the 1.5mm hex wrench in my Craftsman set is the better fit. This set screw is freaking small! Fortunately, the set screw is down low enough to hit the flat face of the rather short D-shaft.

Akai knobs (left) versus Adafruit micro pot knobs (right)

The red knobs look great. The pointers align properly with min and max. The knobs are twice as tall as the factory knobs. The only down-side is the set screw. If you intend to open and close the MPK Mini case frequently, go with the rubber knobs. You will get tired for loosening and tightening the set screws on the micro pot knobs.

New knobs are a quick, inexpensive way to brighten up a front panel from dreary black. Tall knobs are easier to grab, too. There you have it.

MODX+: Glad that’s over!

Posted on September 1, 2022 by pj

Yamaha launched its MODX+ keyboards today. The MODX+ has a few modest improvements over the MODX (Mk1):

1.75GB user waveform memory
Rubberized pitch and mod wheels
New livery (black end-cheeks)
128 tone FM-X polyphony (maximum)

Seamless Sound Switching (SSS) is the same as MODX (limited to 4-part Performances). There are a few on-line videos that are incorrect. The USB audio spec has not changed either.

In case you missed it, Yamaha have a MODX+ Early Adopter Promo Rebate. Register your MODX+ and receive a free FC7 expression pedal and FC5 foot switch. The promotion ends 31 December 2022. That should take some of the sting out of the new prices: $1,499 MAP for the MODX6+ versus $1,399 for the MODX (Mk1). Look for a bundled gig bag, too.

Yamaha are promoting a downloadable Bösendorfer piano. Gotta fill up that expansion memory! Look for new additions to the Montage/MODX+ library in the future. Yamaha IdeaScale participants previewed a new CP-90 piano currently in development. Big multi-samples to drive MODX+ sales.

Anticipatory discussion was filled with wishful thinking and speculation concerning the addition of a second SWP70 tone generator chip and possibly AN-X™ virtual analog synthesis. Judging from the boost in FM-X polyphony, the MODX+ quite likely got the second SWP70.

Speculation about AN-X borders on fantasy. It is based on the premise that an SWP70 is even capable of virtual analog synthesis. Other than Yamaha, does anyone really know what is inside of an SWP70 tone generator?. I don’t.

Adding further doubt for the wet-blanket brigade, I offer the design decisions surrounding the Reface series. The Reface YC and CP are genetic sisters. Both are based on AWM2, both using the SWX08 processor with integrated AWM2 tone generation. Why then, did Yamaha deploy the SSP2 digital signal processor in the Reface CS? Surely, it would have been more cost effective to share the same logic board as Reface YC and CP. Thus, I have my doubts unless SWP70 has some hidden, yet-to-be revealed functional capabilities. Yamaha have the new SSP3 to play with, too.

Given the limitations of the Montage/MODX user interface, including relatively few front panel controls, AN-X on Montage/MODX+ is just putting a bag on the side of a fine product. [Apologies to Tracy Kidder.]

So, I don’t think Yamaha is finished with announcements. There are still CK61™ and CK88™ to account for. Marketing 101 says “Don’t muddy the waters with multiple product launches in a given lane.” Plus, Yamaha marketing is not that big and poor Blake needs to flog the MODX+ while it’s hot. Stay tuned, boys and girls.

Punters are trying to justify the small price increase in terms of component count, etc. Yamaha priced MODX+. Done. If they don’t shift boxes, Yamaha will drop the regional MAP. Currency fluctuation may have more to do with variations in price than component count. Unfortunately, the suits often win.

As to price, one more observation. MODX and MODX+ have crashed the psychological $1,000 USD barrier. Smash it. The MX series is the only sub-$1000 offering. (Reface don’t count with its mini-keys.) There is a big gap between MX and MODX. I don’t think Yamaha can raise prices on the current MX, so maybe something else is coming?

Where to put AN-X™?

Posted on August 26, 2022 by pj

Let’s not miss the forest for the trees…

Wishful thinking abounds — Let’s add an AN-X™ engine to the Yamaha Montage and/or MODX+. From the comments, you would think this is a done deal.

Well, the frenzied demand is certainly there. 🙂 With demand wafts the smell of money. How will Yamaha make money with AN-X?

Occasionally I see a forum comment that is so spot-on, it bears repeating. This comment comes from CyberGene on the Musicplayer Keyboard Corner:

The more I think about it (and knowing Yamaha of course, as well as owning and selling a MODX for being too awkward to work with) I have no high hopes for this hypothetical AN-X being integrated into anything intuitive and easy to use. 🙂 Most certainly it would need to be preprogrammed in advance rather then having a good hands on interface for real time manipulation. Yeah, you can route the knobs and faders to it as usual but still — I just think they should make a YC/CP type of instrument where they add the entire reface CS panel and engine. 😉 Why not add it to the YC73/88, so that it becomes a Nord Stage competitor. Call it a YCS73/88, bingo!

Amen. Could you imagine programming or controlling an AN-X engine within the context of the current Montage (MODX) user interface (UI)? Kill me now.

If Yamaha learned one thing from the YC and CP stage instruments, it’s “stage instruments with a focused user interface and engine (drawbar organ, piano, whatever) are desirable and sell.” [Ka-ching.]

Yamaha marketing folks are players as well as business people. The right way to do analog is to put the engine in a box that it is studded with knobs, buttons and analog controllers. Analog synthesis is meant to be interactive. Yamaha marketing surely knows this and the Reface CS — on a small scale –is proof.

So, AN-X on Montage and MODX+? How would that fit within a menu-based UI which many people find too complicated? In the case of MODX+, would you be happy with four sliders, four knobs and a Superknob for control? Would you enjoy menu-diving? [Sound of shrieking noises here.]

So, thanks, CyberGene for your insight. If Yamaha want to do AN-X right, they need to do it in a focused stage instrument. And make money.

Update: Yamaha have filed for a stylized (figurative) trademark in the European Union. See image below.

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