Review: Yamaha PSS-A50

Before taking a screwdriver and soldering iron to the A50 (Ahem), I’d better write a short review first. 🙂

The Yamaha PSS series keyboards are inexpensive, entry-level instruments which are super lightweight, battery powered, portable and fun. The PSS line is like a small group of fantasy characters where each character has its own super-powers.

  • PSS-E30: A musical game keyboard for younger kids.
  • PSS-F30: “Honey, I shrunk the arranger” keyboard for people who want to play songs with an accompaniment.
  • PSS-A50: A phrase-based music machine which records and speaks MIDI over USB to your DAW or other computer- or table-based music applications.

Last year, I reviewed the Yamaha PSS-E30 Remie and passed it along to our grandson as a Christmas gift. Remie is suitable for young kids, but even Mom and Dad have fun with the musical games.

Yamaha PSS-A50 keyboard [Click to enlarge]

The PSS-A50 (henceforth “A50”) is aimed at people who want more flexibility than the fixed accompaniment styles in the PSS-F30. The A50 has 138 musical phrases — “arpeggios” in Yamaha-speak — that drive an in-built arpeggiator. Twenty-two arpeggios are drum patterns; the rest of the arpeggios are melodic, covering both instrument-specific riffs (strums, bass lines, chord comps) and general purpose phrases like up/down broken chords, etc.

Experienced Yamaha players have seen these arpeggios before. In fact, the A50 reminds me of the Yamaha Synth Arp & Drum Pad iOS application. Without getting into the details, you select a voice, select an arpeggio (“arp”), enable the arp, hit record, and go. If you check out Yamaha’s YouTube tutorials, you’ll see how easy it is to get started.

At this point, I suggest watching Keen On Keys excellent video. It covers all the basics, a brief teardown, and more. I won’t go into such details here. (This chap did a terrific job!) I learned quite a lot from this video including basic “how to use it” information.

Oh, how I long for such reviews in Electronic Music (once Keyboard mag), once again. Ken Hughes, where are you? After reading one of those old product reviews, you actually knew a little about playing the instrument. Now, pfffft!

The sounds

Let’s get down to brass tacks. Like Remie, you won’t get Yamahas top sounds. Shucks, it’s only $100 USD (street price).

Truth be told, even though I regarded the A50 as a candidate for mod projects, I wasn’t too wild about the sounds that I heard in on-line demos. I was hesitant to buy one. Once I got the A50 under my fingers, however, I warmed up.

Basically, the A50 and Remie samples and synth engine are at the same level. The A50 adds touch sensitivity and that, I suspect, makes the difference. Sure, the piano (for example) is uni-dimensional and you can hear it play the same sample louder or softer depending upon strike velocity. The overall effect is more musical, however. Weird how that works?!

The A50 audio OUT is mono. Reverb seems to be the only system effect. Even Yamaha’s cheapest chip implementations have chorus, so it may take a little MIDI magic to unlock that door. The whole sound can be sweetened by out-board effects like maybe a guitar pedal (e.g., TC Electronic Hall of Fame reverb) or a spatializer. I slung an A50 beat through the Korg Volca Mix stereo width and compression effects and got a rather nice result. The Volca Mix Hi/Lo Cut let me isolate the tops and kick, too. I strongly recommend adding external effects.

The A50 motion effects let you juice up your performances. I’m still exploring the motion effects and I’m glad to have them. The motion effects add a way to vary the sound during performance, avoiding a uni-dimensional sound. You get filter fun, pitch bends, slicing and all sorts of sonic mayhem. A few effect types would be good for Hawaiian pedal steel. 🙂 It would be nice to leave the auto wah ON in order to play two-handed funk — a small quibble.

The A50 size, features and price invite comparison against the Yamaha SHS-300 and SHS-500 Sonogenic. Unless you really want the keytar format, I don’t see the value in the SHS-300 versus the A50. I will bet dollars to donuts that the SHS-300 is based on the same chip and samples as the A50. Personally, phrase recording is more fun and creative than a pretend, low-budget, cheap build keytar. Speaker quality is probably a wash between the two and the A50 puts out 1.5W versus 0.7W.

The A50 against the SHS-500 is another story. The SHS-500 voices are definitely better quality. Although the SHS-500 LINE OUT is mono, you can look to its PHONE OUT for stereo. The SHS-500 has PSR E-series DSP effects, three forms of MIDI (USB, 5-pin, and Bluetooth), a General MIDI sound set (available via MIDI only), and jam mode integration with Chord Tracker. The SHS-500 beats the A50 on sound. On the other hand, I prefer the A50’s speaker versus the SHS-500. Of course, the SHS-500 is mainly for playing and doesn’t have an arpeggiator or recorder.

Build quality

One big factor is build quality. The SHS-500 is a solid instrument. The SHS-300 and A50 are cheap. Even though Yamaha specs call out “37 HQ (High Quality) mini keys” for all three keyboards, only the SHS-500 is up to the same quality as the Yamaha Reface series. Yamaha marketing may claim otherwise, but you can feel the difference. The Reface and SHS-500 will stand up to abuse — the SHS-300 and A50, not so much.

As to A50 build quality, the electronic boards and cabling look up to snuff. EMI shielding is absent. Audio quality on battery power or external USB power adapter is good and is reasonably quiet. Powered by my HP desktop, the A50 is susceptible to digital schmutz and produces loud noise through its audio out. One could put blame on the desktop, but nearly all computer switching power supplies are dreadfully noisy. USB powered instruments need better filtering on USB power rails.

In use

I want to use the A50 as a looper: put down a rhythm line and a bass, then jam. It takes a little bit of practice to make glitch-free loops. I wish the A50 applied “measure quantize” to recordings, that is, trim recordings to a clean measure timing boundary. Right now, you have to turn off recording by feel and hope you get it right.

While horsing around with MIDI (another subject for another day), I noticed that the A50 has four parts, each on its own MIDI channel:

  • Keyboard voice: Live, real time performance (Default: channel 1)
  • Arpeggio sequence: Live, real time arpeggiation (Default: channel 2)
  • Recorded keyboard: Recorded keyboard performance (Default: channel 3)
  • Recorded arpeggio sequence: Recorded arpeggio (Default: channel 4)

Hmmm, this makes me wonder if I can layer up to four parts? So far, I can layer 3 distinct musical parts. The fourth part is still elusive.

The main problem is no overdub. It is possible to record two parts at once: arpeggio plus keyboard performance. Thus, you can lay down a drum pattern (arpeggio) and a bass line (by hand). Then, loop the playback and play over the top. Seems like I should be able to add a live arpeggio to the stack.

Anyhow, I found this video (“Yamaha PSS A50 – Jazz Multi Track”) to be instructive. The trick is to get the arpeggio going, select a different instrument, arm record, and play on the first beat. Here is the procedure:

  1. Select drum voice (e.g., voice 39).
  2. Turn the arpeggiator ON.
  3. Select the arpeggio type (e.g., arpeggio 125).
  4. Hold a key to start the arpeggiator.
  5. Press ARP.HOLD to keep the drum pattern running.
  6. Select a bass voice (e.g., voice 14).
  7. Press REC to arm recording.
  8. Play the bass line over the drum pattern. Start playing in time with the drum pattern.
  9. Press REC to stop recording.
  10. Turn the arpeggiator OFF.
  11. Select a piano voice (e.g., voice 2).
  12. Press SHIFT+PLAY to start a looping playback.
  13. Jam over the playback.
  14. Press STOP to stop playback.

Recording doesn’t start until you begin to play the bass line. That locks the bass to the drum pattern. You need to stop recording just before the next loop iteration begins.

If you need some jazzy chords, try: GM7/E, Fm7/B, FM7/D, Em7/A (also notated as Em9, Bm11, Dm9, Am11).

Doggone it, seems like I should be able to layer live arpeggiator into that mix! I’ll keep trying.

Update: Practice makes perfect. Yes, you can get four lines going. I recorded drum and electric piano following the procedure above. With the recorded parts playing, I started a looping bass arpeggio. Finally, I solo’d over the three running parts. Neat, and as complex as you might want for a little practice jam.

Questions

As I begin to explore the A50 MIDI implementation, there are a number of unanswered questions. First and foremost, can I save and restore recorded MIDI data? Does the A50 respond to SysEx messages for reverb and chorus type? Can I drive the A50 with the old Synth Arp and Drum Pad application and make use of its range of arpeggios? Can I load my own simple backing tracks into the A50’s recorder memory?

The final word

After my initial reluctance, I’m glad that I bought the PSS-A50. Apparently, some folks aren’t so happy as A50s turn up as Open Box items quite frequently. Even though $100 is not much, you can save a few extra bucks if you’re willing to buy an open box item. Given the build quality, you might not want to chance it, tho’.

The A50 does not have a full General MIDI sound set. The sound set is close enough for rock and roll, however. Here is an MP3 of the A50 in action (Traffic’s Feelin’ Alright). Wish I could play that piano solo at the end …

Interested in more PSS-A50 content? Check out these posts:

Copyright © 2021 Paul J. Drongowski

Free DJX-II styles: Version 2

I’m happy to announce version 2 of my DJX-II styles for Yamaha Genos, Tyros and PSR arrangers.

These DJ styles are converted from the original Yamaha DJX-II patterns. If you would like to know more about the conversion process, please see: Mining the Yamaha DJX-II.

These are DJ styles, so they only respond to changes in the root note. The chord progressions are cooked into the patterns (just like intros and endings in regular PSR styles). I tried to find the best mapping from DJX-II patterns to style sections. Therefore, some of the DJXII styles have auto-fill, some do not. Longer “fill” patterns are assigned to the intro and ending sections which can play more than one measure.

Feel free to edit, rearrange and customize the styles in order to make them your own. I recommend Jørgen Sørensen’s excellent tools. Jørgen’s site also has documentation and tutorials about styles and style creation to help you along. Please check it out and support his work!

Click on this link to download the ZIP file.

Version 2 includes all of the files in the first collection. Version 2 adds Drum ‘n’ Bass, Disco, House and Trip Hop styles. The ZIP file includes a README.TXT file which should help you get started with the styles. I have also included PDF notation files for people who read music and want to know about the chord progressions, bass lines, and so forth.

Enjoy! The DJX-II style collection is free.

Copyright © 2021 Paul J. Drongowski

Modal Skulpt SE: Review

True to their word, Modal Electronics are shipping the first Skulpt SE virtual analog modules, and I’ve got one. Initial impressions…

Arrival

The Modal Skulpt SE arrives in a neat brown box, well-protected from the strains of travel through the package delivery system. With the pandemic all about, most of us are buying on-line and good packing is important!

Modal electronics Skulpt SE synthesizer

Inside are the Modal Skulpt SE (henceforth, the “SE”), a “UI combinations” card for a quick start, and a moderately short micro USB cable. If you intend to run on battery power, be prepared with six AA cells. A small rear panel slide switch selects USB or battery power. The switch is good enough, but probably won’t stand up to much abuse.

The bad stuff

The bad stuff isn’t so bad, but the SE and I got off to a slightly rocky start.

The SE has a white cover over the front panel. It took a little bit of doing to remove the white cover. I was afraid of bunging the controls… The white cover is a welcome feature, though, as it will protect the front panel going to and from gigs.

The SE’s keyboard and the edge of the side and rear panels are protected with that quasi-adhesive plastic which is meant to be removed before flight. The plastic protects surfaces during manufacturing and is common practice. The (mostly) clear plastic on the keyboard was obviously meant to be removed.

The thin strip of white protective plastic around the edge of the side/back panel had me fooled. I didn’t realize that it was intended to be removed! Thus, when plugging in, “What the?” I didn’t see any legends above the rear panel connectors. “How do they expect us to know where to plug in?” Well, remove the white protective plastic and it’s good to go. Also, the white plastic strip made for the cover’s tight fit. [Redux: minor cover removal issue above.]

The SE puts on a little light show when power is applied. After first boot, I couldn’t get the SE to produce sounds. I removed power and started again — success!

The build

There are plenty of in-depth reviews on-line and in print, so I’m not going to repeat gory details about 32 oscillators, blah, blah. The MusicRadar and Electronic Musician reviews are the best of the lot. (Oddly, Sound On Sound hasn’t reviewed the Skulpt, even the mark one?)

Every review cites the build as “plastic-ky,” etc. Yes, the chassis is made of plastic, but it feels just as robust as the Yamaha MODX. For $199 USD, this is as good as it gets. Build quality is on par with the Korg Volca series. The controls feel a tad light and wobble a little bit. The knobs (endless encoders) and buttons offer enough resistance and tactile feedback for a $199 price.

The keyboard

Reviews also cast shade of the keyboard. Yes, the keyboard stinks for playing chords and seems to play at a fixed velocity level. However, one needs to set expectations appropriately.

It’s not really a keyboard, in my opinion. It’s a group of sixteen function buttons for the sequencer and tone generator. As far as playing is concerned, it’s a “courtesy keyboard” for testing patches and such. (Thanks to Stephen Fortner for that term of trade.) Other low-cost modules provide a courtesy keyboard, but don’t get slagged by reviewers in the same way. Intended usage and criticism don’t rise to mini-key levels (e.g., microKorg, Reface, Keystep, and a plethora of others).

The sound

Well, with these concerns out of the way, Let’s get to the sound!

Electronic Musician ran a mini-synth shoot-out review last Winter. They pegged the mark one Skulpt as a staid, well-behaved sonic pallette — nothing too aggressive. Out of the box, I agree with their assessment and that’s why I bought the SE! I’m not interested in shredding anyone’s ears. I’m looking for temperate pads and leads. If you want aggressive tone, the SE is not the droid you’re looking for.

However the SE does mete out beautiful pads for chill and other modern styles needing laid-back tone. Some of the factory presets have stunning motion and twinkle — truly wonderful. So, sonically, I’m pleased and feel that $199 is money well-spent.

I connected the SE to MODX via MIDI in order to audition the factory presets and I recommend you doing the same. The courtesy keyboard seems to send a fixed MAX velocity level (something I need to verify) and you cannot bring out the nuance of the built-in presets or the full capability of the hardware. Given the usual vagarities of key touch and velocity curves, I had trouble socking the MODX keys and teasing the same sound as produced through the courtesy keyboard. You might want to keep this in mind if you find and test an SE in a brick and mortar store.

Grabbing notes, you will hear note robbing. Oh, yeah, 4 note polyphony. If you want more, buy a second SE and chain it. Note robbing isn’t a big deal, but one must be aware of limitations when playing live. It is what it is.

None of the reviews had much to say about the Spread control which configures and tunes the oscillators. Spread in the range 0 to 64 sets detune. Above 64, the oscillators are spread by interval: major, minor, major 6th, sus 4th, 5th, 5th oct, oct-+5, oct+-, oct–. The ‘+’ and ‘-‘ seem to apply to wave 1 and wave 2 respectively — something which isn’t documented.

The Skulpt SE examples on Modal’s Soundcloud site portray the SE accurately. These sounds may calm your nerves and help you make up your mind when shopping on-line.

The software

Modal provide a software-based Skulpt SE editor for Windows, MacOS and iOS. They even supply a version that executes as a VST3 plug-in so you can modify SE voices while working within a DAW. Modal Electronics distribute six sets of patches: SE Factory bank, Old Factory bank, Stranger Things, Made by Kyle, Skulpt MPE and Skulpt The Mix. You will find the User Manual PDF on the download page, too.

Current firmware is version 2.1. The MODALapp, AKA “the editor,” handles updates. My unit shipped with 2.1 and is up-to-date. [Hint: Check the firmware version on the MODALapp Settings page.]

MODALapp installed easily and immediately recognized the SE. It’s a very convenient way to audition patches, which I am merrily doing as I write this. 🙂 It will be difficult to decide what to keep and what to toss! Patch changes are snappy and holding a note or chord across a patch change produces interesting results, kinda like turning the power off on your Farfisa, only better.

One small niggle — and I do mean small — is the tiny, unreadable size of a few button legends like ‘+’ and ‘-‘. Modal should make these legends bigger.

MODALapp Skulpt SE patch management

A tip or two. If you click on the patch name, MODALapp opens the patch management page. Everything is reasonably intuitive and drag ‘n’ drop. However, I didn’t immediately suss the meaning of the “Local,” “Skulpt Synthesizer” and “Toolbox” sections of the UI. The manual lays it out clearly:

  • Local are patches stored on your PC.
  • Skulpt Synthesizer are patches stored in the SE.
  • Toolbox are scratch patches — a temporary local holding pen for your favorites.

The Toolbox is a convenient and useful idea. It’s a place to put favorites while you cherry pick the factory patches. I wish more tools had a scratchpad like this one. BTW, the Local patch section is preloaded with the old mark 1 Skulpt patches — no need to import them when getting started.

MODALapp Skulpt SE editor

One gets the true measure of the SE’s depth through MODALapp. The modulation matrix is quite large:

  • 8 sources: LFO1, LFO2, MOD-EG, NOTE, VELO, MODW, EXPR, AFTT
  • 34 destinations: CUTOFF, RESO, MORPH, … DIST, DELAY, TIME

The eight virtual knobs in the lower left corner of the editing screen make connect modulation sources and destinations. All major parameters are available, accessible, and easy to find.

How will I use Skulpt SE?

I want to use Skulpt SE as a portable, complementary sound source for Yamaha MODX, Reface and SHS-500 synths. The SE is bigger than I anticipated and is a little too large for a MODX topper. It may have to ride on a soft pad over a few of the rightmost front panel buttons.

Battery operation will help me complete my portable mobile rig. The SHS-500 is a good mate and connects up via 5-pin MIDI. No issues encountered with SHS-500 and Reface YC although I wish the Reface YC transmits MIDI program change messages.

I hope to give the SE’s MPE capabilities a workout. Right now, my only MPE-capable controller is an Artiphon Orba. The Orba does USB and Bluetooth MIDI, so I need to find a way to get the Orba and Skuplt to talk. (A software bridge?) I wish the major players like Yamaha, Korg, Roland, etc. would make Bluetooth MIDI and USB MIDI as easy to connect as 5-pin.

OK, I’m sold and I’m happily rooting for Modal. Based on my experience with Skulpt SE, I would definitely give one of Modal’s full-size offerings a try such as Cobalt or Argon. Modal Electronics are real.

Copyright © 2021 Paul J. Drongowski

littleBits for audio mods?

Here are a few experiments testing littleBits audio post-processing. In the first few cases, audio is produced by a Yamaha SHS-500 synthesizer fed into the LINE IN of a littleBits Microphone module. Outgoing audio is sent through a littleBits Speaker module connected to an external amplified speaker.

I did not draw the littleBits Power module into every example circuit. If you’re experimenting at home, hey, “One, Two, you know what to do…”

The first circuit filters incoming audio:

          PowerSnap 
|
V
Envelope <-- Button <-- PowerSnap
|
V
Mic --> Filter --> Speaker

The Filter modulation input is driven by a littleBits Envelope module. The (audio) input of the Envelope is connected to a littleBits PowerSnap which supplies a constant +5 Volts to the input of the Envelope. A littleBits Button module is connected to the Envelope’s trigger input. (The second PowerSnap assures a full 5 Volt ON signal through the Button.) The Envelope sweeps from 0 to 5 Volts when the Button is pressed. Of course, the Envelope is shaped by its attack and release settings.

The first circuit operates successfully. The audio is filtered according to the Filter’s cut-off and resonance settings. The Filter quacks (a very scientific term!) when the Button is pushed.

The second circuit replaces the Button with a littleBits Pulse module:

          PowerSnap 
|
V
Envelope <-- Pulse <-- PowerSnap
|
V
Mic --> Filter --> Speaker

The Pulse module repeatedly sends a trigger signal to the Envelope module. The triggers cause the Filter to quack correctly. However, there is an audible click when the Pulse module fires — even if no audio is playing. This noise is unacceptible and I don’t know why it is occurring. Power glitches perhaps?

At this point, I began experimenting with the littleBits Threshold module. The (third) simple test circuit below:

    Power --> Dimmer --> Threshold --> Number

demonstrated that my intuition about the Threshold behavior is correct: when the voltage into the Threshold exceeds the threshold setting, the Threshold turns ON and outputs +5 Volts. When the input voltage falls below the threshold setting, the Threshold output turns OFF (0 Volts).

Testing tip: The Number module has a “Voltage” setting in which Number displays the incoming input voltage. You can use a Number module as an in-circuit volt meter.

Given that, I couldn’t determine why the Threshold was not acting like a gate generator when driven by a littleBits audio signal, i.e., driven by the Microphone module in its “Sound” setting. Turns out, the littleBits Microphone module converts the incoming LINE IN signal into its own notion of audio — a signal centered around 2.5 Volts. I connected a Bargraph (or Number) module to the output of Microphone, and indeed, the Microphone sends 2.5 Volts when the audio is silent.

Arg! Once again bitten by the lack of signal documentation! When the Microphone is in its “Other” setting, it converts the input signal to swing from 0 to 5 Volts. Bad news, however. The Speaker module expects audio in the 2.5 Volt centered, littlebits convention and it distorts like a bandit when driven with the “Other” setting.

The 2.5 Volt convention also explains why some folks have observed only a 2.5 Volt sweep in the Envelope output. All of this has serious implications when mixing audio and control signals in littleBits. I need to think about this for a while…

The fourth test circuit demonstrates filtering of regular line level audio:

                              Powered Speaker 
LINE IN
|
Power --> Proto --> Filter --> Proto
|
Synthesizer
LINE OUT

This circuit filters incoming audio. Fortunately, the 2.5 Volt convention does not preclude a simplified signal chain, that is, a chain omitting the littleBits Microphone and Speaker modules. A filter is a filter is a filter, I guess.

Although the Filter module operates on a “regular” audio signal, the Delay module does not. Substituting the Delay module into the fourth test circuit produces nasty noise and a whine. It will process the audio (you can hear repeats, etc.), but the noise/whine is horrible. Screams like a banshee. Bummer.

Bottomline, the littleBits Filter module has potential as an add-in for a PSS-A50 mod (or any other mod) without Microphone and Speaker modules. The littleBits Delay is simply too noisy by itself; one needs the Microphone and Speaker to perform signal conversion. As to the Filter, I need to explore alternatives for modulation. Experiments with using the Oscillator module as an LFO were underwhelming. So far, I haven’t successfully cobbled together an envelope following or audio-trigger envelope. Stay tuned.

Interested in littleBits synth control signals?

Copyright © 2021 Paul J. Drongowski

PSS modding: A few ideas

I’m still thinking about Yamaha PSS mods, most notably, the PSS-A50. Open box A50s are coming on the market and I get the itch to modify an A50. I don’t want to buy a brand new unit since I will immediately tear into it with a screwdriver, drill, and worse! 🙂 Here’s a few more thoughts.

After looking at the PSS-E30 Remie teardown, that speaker has got to go. Even without the speaker, I don’t think there is enough room for the Korg NTS-1 as I first planned.

littleBits filter module

Second-besties, I’m considering a littleBits solution. Lots of folks mod the Korg Monotron to get access to its filter, but oddly, they don’t consider the littleBits filter module. I did a few preliminary experiments with the filter and delay modules using the Yamaha SHS-500 Sonogenic as a stand-in for the PSS-A50 sound generator. The filter and delay sound great although I need to add an envelope generator to make the filter quack and bark.

My main concerns at this point are:

  • Driving littleBits audio without the Microphone module and the Speaker module. Both modules would take up unnecessary space. I’m just don’t know (yet) if regular headphone levels are strong enough for the littleBits 0 to +5 Volt signaling convention.
  • Physically and electrically securing the littleBits modules to themselves and the A50 chassis.
  • Finding 5 volt power in the A50 in order to supply the litleBits modules.

Of course, there’s the problem of mounting the littleBits modules so that the controls (potentiometers) poke through the A50 speaker grill.

I investigated the PSR-F50 audio and digital electronics. The PSS audio amp is mostly likely different than the F50. So, I need to get the A50 service manual. The service manual should help me find the +5 Volt rail, too.

I took another look at the Yamaha YMW830-V processor pin-out. The YMW830-V is also known as the “SWLL” processor. It is a system-on-a-chip (SOC) containing the CPU, memory, and tone generator. The SWLL has five pins (TRST, TDI, TMS, TMS, TCK, and TDO) for serial input/output — most likely USB. This doesn’t bode well for people who want to add 5-pin MIDI to the A50 (or other SWLL-based keyboards).

Reface YC key scan matrix

The PSS series, the Reface series and the SHS-500 share the same 37-key keybed. The key switch matrices are similar. They all break the key range into groups of six keys. Each keybed is a 6 group by 6 key matrix with a dedicated group to scan the fourth C key. The PSS and Reface/SHS differ in the number of key contacts as the Reface/SHS are velocity sensitive and the PSS is not. The Reface/SHS have two contacts per key and the PSS has one contact per key. The Reface/SHS have a total of twelve sense lines (2 lines per key) while the PSS has only six sense lines.

6×6 must minimize ribbon cable width or something because Yamaha will subdivide 61 keys into upper and lower banks in order to deploy six keys per group with 6 groups per bank maximum. You’ll see this practice in the synth product line, too. Just sayin’.

The Yamaha SHS-500 and Reface series use the same MIDI I/O dongle. I came across this rather nice diagram (below) of the SHS’s MIDI port. It should help you to whip up a custom cable or two. [Click image to enlarge.]

Yamaha SHS-500 MIDI circuit and connector pin-out

Hope these observations help someone out.

Copyright © 2021 Paul J. Drongowski

Combo organ: Top octave emulation

Given the scarcity of combo organ top octave generator ICs, what’s a hack supposed to do? Emulate!

I posed a “bar bet” against myself — can I emulate a top octave generator chip with an Arduino? The Arduino is a bit slow and I wasn’t sure if it would be fast enough for the task. Good thing I didn’t best against it…

If you browse the Web, you’ll find other solutions. I chose Arduino UNO out of laziness — the IDE is already set-up on my PC and the hardware and software are easy to use. Plus, I have UNOs to spare. Ultimately, one can always cobble together a barebones solution consisting of an ATMEGA328P, a 16MHz crystal and a few discrete components, if small size is an issue.

A simple passive volume control

There’s not much ancilliary hardware required. A few jumper wires bring out ground and audio signals from the UNO. I passed the audio through a trim pot volume circuit in order to knock the 5 Volt signal down to something more acceptable for a line level input. The trim pot feeds a Sparkfun 3.5mm phone break-out board which is connected to the LINE IN of a powered speaker.

That’s it for the test rig. The rest is software.

I assigned a “root” pitch to Arduino digital pins D2 to D13:

#define CnatPin 13 
#define BnatPin 12
#define AshpPin 11
#define AnatPin 10
#define GshpPin 9
#define GnatPin 8
#define FshpPin 7
#define FnatPin 6
#define EnatPin 5
#define DshpPin 4
#define DnatPin 3
#define CshpPin 2

Thankfully, the Arduino has just enough available pins to do the job while avoiding pins D1 and D0. D1 (TX) and D0 (RX) carry the serial port signals and it’s best to let them do that job alone.

My basic thought algorithm-wise was to implement 12 divide-down counters (one per root pitch) that decrement during each trip through a non-terminating loop. Each counter is (pre-)loaded with the unique divisor which produces its assigned root pitch. Whenever a counter hits zero, the code flips the corresponding digital output pin. If the loop is fast enough, we should hear an audio frequency square wave at the corresponding digital output. This approach is (probably) similar to the actual guts of the Mostek MK50240 top octave generator chip, except that the MK50240 counters operate in parallel.

Each root pitch needs:

  • A digital output pin
  • A note count variable
  • A divisor
  • A state variable to remember if the output is currently 0 or 1

For the highest pitch, C natural, we need declarations:

    #define CnatPin 13 

byte CnatCount ;

#define CNAT (123)

byte CnatState ;

and count down code to be placed within the loop body:

    if (--CnatCount == 0) { 
digitalWrite(CnatPin, (CnatState ^= 0x01)) ;
CnatCount = CNAT ;
}

These are the basic elements of the solution. The rest of the pitches follow the same pattern.

Now, for the fun — making the loop fast enough to be practical. This was a bit of a journey!

First off, I tried the MK50240 divisor values which require at least 9 bits for representation. Using INT (16-bit) counter variables, everything worked, but the final note frequencies were too low — not much “top” in top octave. I cut the divisor values in two, switched to BYTE (8-bit) counter variables, and doubled the output frequencies. Yes, AVR (Arduino) BYTE arithmetic is roughly twice as fast as INT arithmetic. That was the first lesson learned.

The next lesson had to do with how the counters were stored (register vs. memory). If I were writing the code in assembler language, I would have stored all of the counters in AVR CPU registers. (AVR has 32 CPU registers, after all.) Register storage would provide the fastest counter access and arithmetic. However, this is where C language and the Arduino setup()/loop() structure fight us.

Ultimately, I put all code into setup() and ditched loop(). I declared all twelve counters as register BYTE variables in setup():

    register byte CnatCount ; 
register byte BnatCount ;
register byte AshpCount ;
register byte AnatCount ;
register byte GshpCount ;
register byte GnatCount ;
register byte FshpCount ;
register byte FnatCount ;
register byte EnatCount ;
register byte DshpCount ;
register byte DnatCount ;
register byte CshpCount ;

The compiler allocated the counter variables to AVR CPU registers. This enhancement doubled the output frequencies, again. Now we’re into top octave territory!

The third and final lesson was tuning. The Mostek MK50240 is driven by a crystal-controlled 2000.240 kHz master clock. The emulated “master clock” is determined by the speed of the non-terminating loop (cycling at the so-called “loop frequency”):

    for (;;) { 
if (--CnatCount == 0) {
digitalWrite(CnatPin, (CnatState ^= 0x01)) ;
CnatCount = CNAT ;
}

...

delaySum = delaySum + 1 ;
}

My original plan was to tune all twelve pitches by changing the speed of the non-terminating loop. I discovered that such timing was too sensitive to code generation to be controllable and reliable. The biggest delay that I could add to the non-terminating loop was “delaySum = delaySum + 1 ;“. In the end, I manually tuned the individual note divisors.

A fine point: I chose the divisors to achieve a wide resolution in 8 bits. Eight bits is “close enough for rock and roll,” but not really enough for accurate tuning.

As usual, the path to the solution was zig-zaggy and not straight. Here is a ZIP file with all of the code and my working notes. I included source code for the intermediate experiments so you can re-trace my steps. Have fun!

Copyright © 2021 Paul J. Drongowski

Review: zplane deCoda

A recent thread on the Keyboard Forum (“What was the first song you figured out by ear?”) brought up memories of high school and combo organs. One of the most popular tunes of the time was “Space Rock Part 2” by The Baskerville Hounds. Air play on Ghoulardi was a big boost to its popularity and it really brought people onto the dancefloor. “Space Rock” is pretty much a rip of The Stones’ “2120 South Michigan Avenue,” albeit way up-tempo than the Stones’ version. Sly Stone knocked out his own titled “Buttermilk.” If you’re wanting a modern update, listen to the 2015 Jerry Cortez cover.

The “Space Rock” organ solo was the solo to know as a teen. At the time, I was paying off my Farfisa and didn’t have any money for records, so the old “drop the needle until you got it” method wasn’t for me. My bandmates were always on my back about it and they didn’t accept my “Guys, they’re just jammin'” excuse. I tried to cover the head and then improvise. Oh, well.

I’m pulling together a backing track for “Space Rock/2120” and it seemed like the time to transcribe the solo. Enter zPlane deCoda. In a nutshell, zplace have deployed their time/pitch stretching and DSP expertise to the problem of picking out tunes from audio. (See the Sound On Sound review for more information.) It’s not an audio-to-MIDI converter, so you still need to use your ears and eyes.

First, ya drag (or open) an audio file in deCoda. deCoda gives you two views: a standard (amplitude) waveform view of the audio and a spectrographic plot. The spectrographic plot is like a DAW piano roll. Instead of notes, however, it displays the sonic energy present at each pitch. You can (kind of) see the notes in the song — pitch and duration. I spent most of my time in the spectrographic display.

zplane deCoda in action

Optionally, you can turn on an XY panel (at right in the image above) that lets you focus playback and analysis on a particular “region” of the stereo field and audio frequency spectrum. Thanks to the XY panel, you can eliminate the bass and high-end sibilance. Blobs light up in the XY panel during playback as notes come and go.

deCoda offers a number of playback controls. You can playback at 1/4, 1/2, 3/4 and full speed. You can transpose up and down. You can change the tempo. My recommendation is to get the best mix of key, tempo and XY region before deep diving transcription.

Like Yamaha’s Chord Tracker, deCoda discovers key, tempo, chords and song sections. As mentioned, you can modify deCoda’s decisions. Compared against Chord Tracker, I would give Chord Tracker the edge. (Yamaha have invested a pile ‘o’ cash into music analysis.) Both tools handle simple chords OK, but forget jazz chords (no 11th and 13th chords) or gospel voicings.

After quickly munching “Space Rock”, deCoda had the key right, but half the actual tempo. The Hounds played “Space Rock” at a blistering 156 BPM. deCoda says 78 BPM. That’s OK, but…

One of the coolest deCoda features is the ability to draw notes on top of the spectrographic display. The notes play back through a simple synthesizer (think Casiotone). A mixer controls the relative level of song audio and synthesized tones. Once I got a little more skilled with deCoda, I found myself changing the relative levels quite often in order to A/B the original audio and the drawn notes. I wish deCoda offered a few different synth voices as the simple tones blended with the organ notes making it difficult to sort out the sounds by ear.

With a little practice, you can begin to pick out the notes by sight as well as ear. 1/4 playback is good for checking note start and duration. “Space Rock” is a mono mix and a mess of frequencies with that danged 60’s ring-y reverb. Thus, there are many false positives — places where you think there is an organ note, but it’s actually the frapping guitar. I wish deCoda could color notes according to timbre. Man, that would be quite the time-saver.

To compensate, I found myself playing the notes on keyboard, mainly to check fingering. “Space Rock” is one of those lazy blues tunes where the keyboardist just rocks his or her fingers around in one basic hand position. It’s difficult to read piano roll notes in real-time; I’d love to have even a simple staff viewer.

Now for the “but…”. deCoda can export the notes as a Standard MIDI File (SMF). Very good. deCoda produces MIDI notes that follow the identified tempo. When the SMF is imported into a DAW or notation tool, it arrives with the identified (or tweaked) tempo. Note play back sounds right, but if you change to the correct tempo in the tool, note starts and note durations are off (i.e., half of what they should be). I had to fix the note starts and durations in Sonar, save another SMF and import the modified SMF into Sibelius. Bummer.

I discovered the tempo and note export gotcha downstream. I also found that I wanted to work and play in G Major, not F# Major, AKA “that frapping guitar key.” I had already started a draft in Sibelius and it became a question of how much work I wanted to throw away. It’s better to get these considerations right from the start before export and downstream work.

Speaking of Sibelius, I really longed to have the identified notes in notation form, not piano roll. Under Windows 10, I couldn’t work in Sibelius and deCoda simultaneously. They did not work together — some kind of MIDI or audio system conflict. One or the other tool wouldn’t play when they were both open at the same time. In a few cases, I had to resort to notation paper and pencil to transfer identified notes into Sibelius, exit Sibelius, then re-start deCoda. Painful.

After all is done, I arrived at a decent transcription in Sibelius. (See image below; click to enlarge.) After seeing and playing the solo against a rough backing track, I think deCoda is about an eighth to a quarter note ahead of the beat. I’m not sweating it too much as playing “Space Rock” comes down to feel. However, it might be a factor when an accurate score is needed for chart-driven players.

Space Rock Part 2 (solo)

zplane deCoda is a worthwhile tool. It won’t automatically transcribe, but it is a decent assistant. The note editor and MIDI export are a real boon as I a keep a book of charts for reference. The XY plot is also a worthy mix visualization tool and has been repurposed in zplane peel. I hope that deCoda continues to invest in deCoda as I would love to have timbre coloring. That’s a tough technical problem, but cracking that nut would put zplane way out in front competetively.

Copyright © 2021 Paul J. Drongowski

Combo organ: Top octave generator

So far, we’re taken a short trip through combo organ technology from early days in the 1960s to modern day workstation voices:

I hope you enjoyed those articles! This post fills in the middle bits — how large scale integration changed combo organ design.

Farfisa tone generation circuit

During the 60s, Vox, Farfisa and other manufacturers employed a similar approach to tone generation. Each organ contained twelve tone generation boards one for each semi-tone in the Western well-tempered scale. Each board implemented:

  • An oscillator to produce the a base root tone, and
  • Several (digital) dividers to derive the ancilliary tones one or more octaves below the root tone.

Vox, Farfisa, and so on used discrete components (transistors, resistors, capacitors, etc.) to implement the oscillator and dividers. These boards were dense and busy with many hand-soldered joints. The Farfisa board, for example, contained 12 transistors, 40 resistors, 25 capacitors and a tunable inductor coil. Assembling, testing and debugging a board like that is quite expensive and labor intensive.

Having lived through the transition from discrete semiconductor circuits to small scale integration (SSI) and then large scale integeration (LSI), I can attest to the revolution initiated in the LSI era. (Not to mention the transition to very large scale integration!) LSI and mixed signal components enabled sound generators like the Texas Instruments SN76477 Complex Sound Generator, General Instruments AY-3-8910/8912, and other ICs — and sounds — favored by chip-tune enthusiasts.

LSI revolutionized combo organ design, too. Mostek (and others) introduced top octave tone generator chips. The well-known Mostek MK50240 (PDF datasheet) has inputs for power, ground and master clock:

    Pin#  Name  Purpose 
---- ---- --------------
1 VSS Supply voltage 15V (typical) 11V (min) 16V (max)
2 Clock Clock 2000.240kHz (typical), 2500kHz (max)
3 VDD Ground

The MK50240 generates each of the high frequency root tones:

    Pin#  Note  Divisor 
---- ---- -------
16 CLow 478
4 C# 451
5 D 426
6 D# 402
7 E 379
8 F 358
9 F# 338
10 G 319
11 G# 301
12 A 284
13 A# 268
14 B 253
15 CHigh 239

The MK50240 has twelve dividers which divide the master clock frequency into the root tone frequencies.

Advantages of the MK50240 should be readily apparent! A single MK50240 replaces all twelve oscillators. Even better, the master clock can be generated from a 2000.240 kHz crystal resulting in superior temperature (pitch) stability. Old discrete circuits are notoriously temperature sensitive.

But, wait, there’s more. Thanks to digital LSI, each divider chain can be replaced by an MOS ripple counter. Consider the CMOS CD4024. (Please see the CD4024B functional diagram below.) The CD4024 is a 7-stage ripple counter that divides the incoming clock signal into seven auxilliary tones at each octave below the input frequency.

The nightmare of discrete oscillators and dividers can be replaced by a single MK50240 and 12 CD4024 ripple counters: 13 dual in-line packages (DIPs) and a handful of coupling capacitors for good measure.

Of course, one must still confront the rat’s nest of wires and signal diodes needed for key switching… To get a sense of wiring complexity, I suggest looking at the design of the vintage PAiA Stringz ‘n’ Thingz digital keyboard or PAiA Oz portable mini-organ. Yes, I assembled a Stringz ‘n’ Thingz — without too many bad solder joints, thank goodness. Organ wiring was a nightmare before microcomputer-based key switch scanning and digital control.

With LSI and micro-computers, organ builders collectively breathed a sigh of relief. Unfortunately, ease of design and manufacture came with a penalty — lack of sonic charm. Each of those old-tyme discrete oscillators were slightly out-of-tune with one another. Thus, there’s a subtle richness in the old discrete designs that is missing in full-on digital implementations.

Before leaving the MK50240 behind, I want to mention the PAiA EK-1 top octave experimenter’s kit.

PAiA EK-1 board (component side)
PAiA EK-1 board (trace side)

PAiA was (and is) a terrific resource for experimenters. I built several PAiA kits including the Stringz ‘n’ Thingz and the Gnome synthesizer. I also played with the PAiA EK-1 top octave experimenter’s kit. If you would like to learn more about the Mostek MK50240, check out the PAiA EK-1 instruction booklet. Shame you can’t find many MK50240s today…

Copyright © 2021 Paul J. Drongowski

Arpeggio to style conversion

Let’s get one out of the vault… 🙂

The Motif XS/XF (MOX/MOXF) and Montage (MODX) arpeggios and performances are a great source of inspiration. Unlike Yamaha’s arranger series, the built-in phrase library is rich in urban and chill patterns. For some odd reason, one of the classic XS/MOX performances — “Dresden At Night” — never made the leap to Motif XF. And, it’s missing from Montage/MODX, too.

A PSR Tutorial forum member sought help resurrecting Dresden At Night, albeit a recreation for the PSR-SX700 arranger. I thought I would help out since I wrote a series of articles about MOX performance to style conversion:

The end result of that work is a small collection of PSR (Tyros, Genos) styles based on MOX (Motif XS) performances.

If you would like to try Dresden At Night or experiment with a conversion of your own, download the free ZIP file.

MOX performances have four parts (voices). Each part has up to six musical phrases (arpeggios) associated with it. Six front-panel buttons select the currently playing set of arpeggios, i.e., button one selects the first arpeggio for each set and so forth. To get the basic MIDI data, I played each arpeggio (group) for four measures while recording in MOX performance quick record mode. I wrote out the MIDI data as a Standard MIDI File (SMF), transfered the SMF to PC, and imported the SMF into a DAW (Sonar).

Dresden At Night is a downtempo (91 BPM), urban-ish chill performance. It has four parts:

Part# Voice    Name              NoteLo NoteHi VelLo VelHi Level Pan
----- -------- ---------------- ------ ------ ----- ----- ----- ---
1 PRE8:070 8Z Heavy Hearts C-2 G8 1 127 81 C
2 PRE3:053 Dark Bass C-2 G8 1 127 51 C
3 PRE7:110 Ibiza Groove C-2 G8 1 127 127 C
4 PRE5:121 Smooth BPF Sweep C-2 G8 1 127 73 C

The first part is the rhythm voice and the second part is the bass voice. As we’ll see below, arpegiation is turned for these two parts. The third and fourth voices are a play-along pad layer and arpeggiation is disabled. Thus, the rhythm and bass parts provide a looped backing while the pad voices provide an atmospheric you-steer-it, right hand part.

Here are the arpeggio assignments:

Arp#1 Tempo:91              Arp#2 
----- -----
1 MA_8Z HeavyHrt1 1 MA_8Z HeavyHrt3 ON
2 MB_WestCoastPop _XS 2 MA_WestCoastPop _XS ON
3 MA_Space Arp 3 MA_Space Arp OFF
4 MA_Up Oct1 4 MA_Up Oct2 OFF
Arp#3 Arp#4
----- -----
1 MA_8Z HeavyHrt4 1 MA_8Z GatedBt3 ON
2 BA_Jazz Pop _XS 2 FB_WestCoastPop _XS ON
3 MA_Space Arp 3 MA_Space Arp OFF
4 MA_Up Oct4 4 MA_Down Oct1 OFF
Arp#5 Arp#6
----- -----
1 MA_8Z ChillBrk4 1 BA_Sp SFX ON
2 MB_WestCoastPop _XS 2 MA_WestCoastPop _XS ON
3 MA_Space Arp 3 Off OFF
4 MA_Down Oct2 4 Off OFF

The Arpeggiator is turned ON for Parts 1 and 2 only.

A big factor is the “8Z Heavy Hearts” drum kit. The “8Z” in its name means “eight zone”. Eight zone (8Z) voices are a Motif innovation beginning with the XS (MOX) family. If you would like more information, check out these earlier posts about eight zone voices:

8Z voices aren’t drum kits. They are implemented as synth voices and are just a clever way of using the eight elements which make up a voice. The eight zones (8Z) are divided across specific note ranges. 8Z Heavy Hearts assigns waveforms (zone sounds) in the following way:

Element#  Note Low  Note High  Waveform 
-------- -------- --------- --------------
1 C0 F#0 Bd T9-1
2 G0 C1 Bd Hard Long
3 C#1 D1 Sd Elec12
4 D#1 F1 Sd HipHop6
5 F#1 A1 HH Closed D&B
6 A#1 C2 HH Open T9
7 C#2 C4 Clap AnSm
8 C#4 C6 Shaker Hip2

Yamaha messes with each of the zones in crazy ways and ties keyboard notes to voice parameters (AKA “key follow”). For 8Z Heavy Hearts, the most notable effect is how the Clap AnSm pitch follows the keyboard.

Arrangers (even Genos!) don’t have 8Z voices. They have standard drum kits where each MIDI note is a separate drum instrument. In order to make a PSR style using a DAW, one must translate the 8Z MIDI notes to standard drum kit notes. You need to assign appropriate drum kits (e.g., DrumMachine, Analog T9, House, Break or HipHop) to style parts 9 and 10 (MIDI channels 9 and 10) and copy the Heavy Hearts MIDI data to both Parts. Then, delete the notes that aren’t needed in a style part, compress each zone into a single drum instrument, and map the resulting “compressed” notes to the appropriate drum instrument(s). So, for example, all of the notes in C0 to F#0 might be compressed into the Kick T9 1 instrument (B0) in the Analog T9 Kit, which is one of the target drum kits.

I found two PSR drum parts to be enough. However, styles are flexible and you could assign a third (fourth, …) drum kit to one of the other style parts. There’s nothing in Yamaha styles that prevents this. It’s just that parts 9 and 10 (MIDI channels 9 and 10) are conventionally assigned to drum parts in a style.

I went with two PSR drum kits: Analog T9 kit and Drum Machine kit. Here is one possible assignment:

Note Low Note High Waveform       Instrument        Note#   Kit 
-------- --------- ------------- ---------------- ------ -----------
C0 24 F#0 30 Bd T9-1 Kick T9 1 35 B0 AnalogT9Kit
G0 31 C1 36 Bd Hard Long BD Hard Long 24 C0 DrumMachine
C#1 37 D1 38 Sd Elec12 Snare Analog CR 63 D#3 DrumMachine
D#1 39 F1 41 Sd HipHop6 Snare Hip 1 86 F#3 DrumMachine
F#1 42 A1 45 HH Closed D&B Hi-Hat Closed Syn 91 A4 DrumMachine
A#1 46 C2 48 HH Open T9 Hi-Hat Open T9 46 A#1 AnalogT9Kit
C#2 49 C4 72 Clap AnSm Clap Analog Sm 27 D#0 AnalogT9Kit
C#4 73 C6 96 Shaker Hip2 Analog Shaker 57 A2 DrumMachine

A lot of detail, huh? Nobody said style conversion was easy. 🙂 In the end, I spread each zone across multiple drum instruments of the same type, i.e., assigning the Shaker Hip2 zone to a few different Analog Shaker sounds in the Drum Machine kit. Part of 8Z Heavy Hearts’ charm is the subtle sonic variation provided by each zone.

Trying to keep this all straight in the DAW piano roll is cognitively challenging. Did I say, style conversion isn’t easy? 🙂

Fortunately, one can loop four bar sections and play the MIDI through the arranger (Genos, in this case) just like a MIDI song. Then, it’s the usual tweak, listen, rinse, repeat edit process. When the MIDI is tweezed to your liking, you need to add MIDI markers to delimit the style sections. (BTW, leave a one bar MIDI set-up measure at the beginning.) Style section markers are:

    Set-up measure 1: SFF1 
Set-up measure 1: SInt
Main sections: Main A, ...
Fill sections: Fill In AA, ...
Break section: Fill In BA, ...
Introduction: Intro A, ...
Ending: Ending A, ...

At a minimum, you need a few MIDI set-up System Exclusive (SysEx) messages at the beginning of the SMF (measure 1, beat 1):

    F0 7E 7F 09 01 F7                 GM Reset 
F0 43 10 4C 00 00 7E 00 F7 XG System ON
F0 43 10 4C 02 01 00 01 16 F7 Reverb type
F0 43 10 4C 02 01 20 16 00 F7 Chorus type

Reverb is the “Light Hall” preset and chorus is the “Tempo Cross 1” preset. The tempo cross delay is an 8-beat echo.

Which brings me to a necessary ingredient: crunch. 8Z Heavy Hearts gets a lot of its appeal from the Lo-Fi effect:

#  Parameter                   Val  Hex   Meaning 
-- -------------------------- --- ---- --------
1 Sampling Frequency Control 4 0x04 8.82kHz
2 Word Length 98 0x62
3 Output Gain 7 0x07 0dB
4 LPF Cutoff Frequency 56 0x38 12kHz
5 Filter Type 1 0x01 PowerBass
6 LPF Resonance 63 0x3F 6.3
7 Bit Assign 4 0x04
8 Emphasis 1 0x01 On
10 Dry/Wet 88 0x58 D<W24
15 Input Mode 1 0x01 Stereo

Since we need Lo-Fi on both style parts 9 and 10, I configured the variation effect as an XG SYSTEM effect. Parts 9 and 10 also require variation send (MIDI CC#94) set to 127. Add a CC#94 message to parts 9 and 10 in the set-up measure. Here are the MIDI System Exclusive messages to add to the set-up measure:

F0 43 10 4C 02 01 40 5E 13 F7       Variation type 
F0 43 10 4C 02 01 5A 01 F7 Variation SYSTEM
F0 43 10 4C 02 01 56 40 F7 Variation return
F0 43 10 4C 02 01 58 10 F7 Variation send to reverb
F0 43 10 4C 02 01 59 10 F7 Variation send to chorus
F0 43 10 4C 02 01 42 00 04 F7 Variation parameter 1
F0 43 10 4C 02 01 44 00 62 F7 Variation parameter 2
F0 43 10 4C 02 01 46 00 07 F7 Variation parameter 3
F0 43 10 4C 02 01 48 00 38 F7 Variation parameter 4
F0 43 10 4C 02 01 4A 00 01 F7 Variation parameter 5
F0 43 10 4C 02 01 4C 00 3F F7 Variation parameter 6
F0 43 10 4C 02 01 4E 00 04 F7 Variation parameter 7
F0 43 10 4C 02 01 50 00 01 F7 Variation parameter 8
F0 43 10 4C 02 01 54 00 58 F7 Variation parameter 10
F0 43 10 4C 02 01 75 01 F7 Variation parameter 15

At this point, you could save the MIDI to “DresdenAtNight.sty” and load it into your arranger as an SFF1 format style. The arranger should create the style CASM segment. As an alternative, you can add a CASM segment to the SMF with Jørgen Sørensen’s CASM editor. You might as well download his OTS editor, too, and use it to add OTS voice settings to the new style as well. Or, you can do this sort of work on your arranger itself. Mid- and high-end Yamaha arrangers save styles as SFF2 format, which is one way to convert from SFF1 to SFF2. I highly recommend Jørgen’s site, tools and style creation tutorial.

BTW, you can recreate Dresden At Night on MODX (Montage). Create a new MODX performance with 8Z Heavy Hearts and Dark Bass. 8Z Heavy Hearts has the appropriate arpeggios by default. You’ll need to assign different arpeggios to the Dark Bass part. Modify effects as needed. Choose and add pad or lead voices to give your right hand something to do. Done! Use the Scene buttons to switch arpeggio groups.

Copyright © 2021 Paul J. Drongowski


Combo organ: Reface YC

Checking out organ-related threads in the music forums, combo organs get short shrift while most folks focus on the Hammond B-3 tonewheel sounds. Today’s post will (almost) ignore the B-3…

Organ-focused keyboards from Nord, Hammond, Yamaha and others have combo organ emulations in addition to tonewheel synthesis. All offer two vintage flavors: Vox and Farfisa. Nord and Hammond throw in pipe organ, piano, EP and instrument emulations, too, making for full all-rounders.

Drawbar control abounds! In the case of Vox, each physical Nord drawbar corresponds to a Vox Continental drawbar footage (with possible extensions). Nord Electro 6, for example, offers 16′, 8′, 4′, 2′, II, III, IV and sine. The 16′, 8′, 4′, IV and sine are basic Continental tones. Nord’s emulation kicks the basics up to dual-manual, Continental II territory by adding a 2′ footage and two overtone mixtures, II and III. The mixtures consist of the following ranks:

  • II: 5 1/3′ and 1 3/5′ pipes
  • III: 2 2/3′, 2′ and 1′ pipes
  • IV: 2 2/3′, 2′, 1 3/5′ and 1′ pipes

The III and IV mixtures add the Hammond-like overtones missing from the original Continental. Hammond employ a similar Vox drawbar assignment in the Sk1/Sk2 series.

Discrete voice (tab) stops pose a minor problem: How to provide discrete On/Off control with sliders (drawbars)? In the case of Farfisa emulation, Nord and Hammond assign each Farfisa tab to a drawbar:

    Drawbar  Farfisa (Nord)  Farfisa (Hammond) 
------- -------------- -----------------
1 Bass 16' Bass 16'
2 Strings 16' Strings 16'
3 Flute 8' Flute 8'
4 Oboe 8' Oboe 8'
5 Trumpet 8' Trumpet 8'
6 Strings 8' Strings 8'
7 Flute 4' Flute 4'
8 Strings 4' Piccolo 4'
9 2 2/3 Strings 4'

The Hammond voice set is the same as the Farfisa Combo Compact. The Combo Compact Deluxe replaced the Piccolo 4′ voice with a bright 2 2/3′ overtone tab, adding a bit of Hammond-like whistle. The Nord voice set covers the Combo Compact Deluxe model.

Yamaha have taken their own approach to combo organ emulation with the YC61. The YC61 synthesizes tonewheel tones through Virtual Circuit Modeling (VCM) that emulates the sound of analog tonewheels and associated circuitry. Vox (YC61 organ model F2) and Farfisa (model F3) sounds are produced using frequency modulation (FM) synthesis. The YC61 also provides a sine wave “combo” model (F1). The YC61 drawbars bring in the usual drawbar footages with the exception of the 1′ drawbar which is disabled in all FM models (F1, F2, and F3).

Gotta wonder if we can port the F1, F2 and F3 FM organs to Montage and MODX?

Thanks to the frapping pandemic, I have yet to play a YC61. (Grrr.) However, I have played the Nord Electro 6D and Hammond Sk1. Both provide excellent combo organ sounds. Pipe organ (Nord and Hammond) is a big plus for a church player. I give Nord’s orchestral samples and library the edge over Hammond.

Yamaha Reface YC

Yamaha Reface YC promises tonewheel and combo organ sounds on the cheap. By and large, it delivers. I have really worked the Reface YC as a rehearsal instrument and as a gig instrument in church. That said, here are some detailed observations (positive and negative).

Reface YC Typical Vox and Farfisa settings (Source: Yamaha)

I roll my eyes a bit whenever anyone posts about how they “wish the Motif XF (Montage, MODX) had the Reface YC technology inside.” News flash, the Reface YC shares much of its technology with Motif XF, Montage and MODX already. Yamaha simply repackaged and revoiced the basic AWM2 DNA in a wonderfully accessible form. Wisely, Yamaha reacted to the warm user reception and reaction caused by the YC and its popular pal, the Reface CP. Yamaha is now taking it to the bank with the current full-sized CP and YC keyboards.

The Reface YC emulates five different organ models:

  • H: Hammond tonewheel
  • V: Vox transistor organ (1960s)
  • F: Farfisa transistor organ (1960s)
  • A: Acetone transistor organ (1970s)
  • Y: Yamaha transistor organ (1972)

The Reface YC drawbars, buttons and sliders directly map to Hammond organ drawbars and controls. What about the combo organs?

I stripped away all of the effects (percussion, chorus, distortion, reverb, etc.) and sampled each of the five voices (8′ foot pipe, middle C). The five waveforms are pictured below. The H and V waves, especially, have a sinusoidal shape. The nasal F wave is truly unique. [Click image to enlarge.]

Reface YC waveforms (middle C, 8′ organ stop)

Since the Vox Continental had drawbars itself, the YC drawbars correspond to a single Vox drawbar sound (the V wave) played back at the appropriate footage (pitch). The YC Vox is based on a single Vox wave, just like the Montage (MODX and Motif XF). In Montage land, this is the “Vx Drawbar1-3” waveform. In the “you get want you pay for” department, the YC Vox does not have the reed and sine drawbars/sounds, and you must dial in the II, III, and IV mixtures yourself.

For the sake of authenticity, one should never put a combo organ through the rotary speaker effect. Trust me. Most of us in the 60s could barely afford an organ and an amp, let alone buy a Leslie. Then there is the issue of getting to the gig. Everything needed to fit into the back of Dad’s car!

The YC Farfisa, Acetone and Yamaha organ implementations follow the same design as the Vox. Each of the four combo organs (V, F, A and Y) consist of a single wave played back at different pitches according to drawbar footage.

Listening to the stripped down F wave, my first thought was “Accordion!” The 60s Farfisa organs were designed by accordion makers and I believe that the raspy Farfisa tone is their intentional attempt to build an electronic accordion. [Memories of Mom and Dad saying, “Why don’t you play accordion and learn a few wedding songs?” Who knew?] The name “Farfisa” is a contraction of “Fabbriche Riunite De Fisarmoniche”, the company formed by pre=World War 2 Italian accordian makers Settimio, Soprani, Scandalli, and Frontallini. It ain’t an accident, folks.

Thus, in terms of control, the Reface YC is quite unlike a real Farfisa Combo Compact with its discrete voice tabs. Once again, you pay more for Nord or Hammond and you get more authenticity. That doesn’t mean you can’t get a decent Farfisa tone out of Reface YC. It’s raspy enough for Wooly Bully and other cover songs. The chosen F wave is versatile and, well, Farfisa voices are pretty much the same wave filtered differently. The screaming Tone Boost is missing in action, though.

I give the Reface YC an A- and B+, respectively, for Vox and Farfisa authenticity. I don’t have any direct experience with Acetone and early Yamaha organs — just the soundtracks of old Japanese kaiju (monster) movies. The YC sounds realistic enough.

I experimented with YC percussion in isolation, too. Each of the Reface combo organ voices has its own distinctive percussion. I recommend trying this at home as some of the settings are almost clav-like and would do in a pinch. A few settings remind me of the 1970s Crumar Roadrunner electronic piano — the most crap-tastic electronic piano ever made. Yes, I owned one, played one, and sold it off as fast as humanly possible. 🙂

After analyzing the Reface YC, I understand better how Yamaha teased organ voices from modest hardware. I also have renewed respect for the Montage (MODX, Motif XF) organ voicing and real-time control. The Montage, MODX and Motif XF have all the sonic materials necessary to meet and/or best the Reface YC. Still, you can’t throw a Montage or a MODX into a tiny bag and jump on the bus, train or plane.

DIY drawbar control

If you want to add a few drawbars via MIDI, try my Sparfun Danger Shield drawbars project. Or, at least read my Sparkfun Danger Shield review.

Crumar D9U DIY MIDI drawbar controller

I also gave the Crumar D9U drawbar kit a spin:

The Crumar D9U is a DIY, Arduino-compatible drawbar kit. This series of articles describe my experience from beginning to end and include C code. Don’t want DIY? Then try the ready-made Crumar D9X.

Copyright © 2021 Paul J. Drongowski