Category Archives: Music technology

SampleTank IOS and Miroslav vs. Korg Module Pro

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Just like finding a 20 dollar bill in a drawer full of old socks, it’s a pleasant surprise to discover that you already own a useful iPad music app and simply forgot about it. Thus, I installed IK Multimedia SampleTank IOS on my iPad and gave it a try. (Again) Even better, I restored in-app purchases, finding additional B-3 organs and, ta-da, Miroslav Symphonic Mobile Edition. (Henceforth, “Miroslav”.)

Miroslav goes back a long way to 1994. The mobile edition is a cut-down version of the current, big and improved Miroslav Philharmonic 2 library. The full library is 2.27GB while the Mobile Edition tips in at a modest 532MB.

Miroslav Vitouš, by the way, is one heck of a jazzer. I was well-aware of his work as a leader and as a sideman (Herbie Mann, Chick Corea, Roy Ayers, Larry Coryell, and others) before hearing the original Philharmonic library.

Sonically, Miroslav has always had its own unique character. You either love it or dislike it. I’m on the love side although some of the string sections sound a tad dated. I like the woodwinds and horns best, rating them a notch above the Korg Module Pro voices. As to variety and solo instruments, Miroslav Mobile trounces Module Pro in the orchestra department.

As to B-3 organs, Module Pro wins the contest. Frankly, I am not a fan of SampleTank IOS drawbar organs, which are very rock-oriented. Further, SampleTank IOS does not have a rotary speaker simulation built-in. I can only assume that IK want you to purchase Hammond B-3X for iPad ($130 USD) or AmpliTube Leslie. I found, however, that I can easily switch between Module Pro and SampleTank IOS while keeping the Korg Microkey Air connected over Bluetooth. Problem solved.

As to church organ, I blended SampleTank’s Church Organ Air with Miroslav’s Cathedral Organ. The solution is good enough for basic hymn playing. I still plan to purchase Module’s organ (and clav) expansion pack when it goes on sale. The organ expansion pack includes a few traditional pipe organ voices.

SampleTank IOS plus Miroslav Mobile complements Korg Module Pro rather well. I forgot about dear old Miroslav after moving to our new house and to a new iPad. I’m glad that I remembered! If you need to choose one app, there are differences to be considered in the synth engines. Please read on.

Korg Module Pro

As I mentioned in my review, Module Pro with the performance expansion pack allows two-voice layers and splits. Splits and layers are created and stored within set lists.

Korg Module Pro Set List management

Module’s Set List management screen lets you choose and load a combination (combi). Tapping the keyboard symbol on the right hand side of the selected entry takes you to the screen where you set the mode: Single voice, Layer or Split. There, you can balance levels, shift octaves and set the split point.

If a voice needs tweaking, you can switch to the standard Module instrument screen for voice edits. When finished, you need to switch back to set list mode and save the set list. The set list combi retains any changes. (You need to tap the file icon in the upper left corner to show the appropriate pop-up menu.)

Korg Module Pro edit screen for sample-playback voices

SampleTank IOS

Instead of set lists, SampleTank has its Live mode where you can create multi-voice layers and splits. SampleTank is better-featured that way, allowing up to eight voices to participate in a combi.

SampleTank IOS Live mode screen

In the example above, instruments are split left (two string layers) and right (two flute layers). You can see the split and layer relationships in the pane at the bottom of the screen. Since it’s all touch-based, one slides split points left and right. It’s quite natural. Please note that this example patch is already well-beyond Module Pro’s simple two-level layers and splits. SampleTank IOS also allows overlaps around the split point, eliminating a jarring sonic change when a musical line crosses the split point.

Unlike Module, SampleTank IOS has a strip of control knobs for voice tweaking. Both apps let you change attack, release, cut-off, resonance, effect type and effect levels. This level of basic editing is usually sufficient.

SampleTank IOS level and pan control in Live mode

All four voices in the example are on MIDI channel 1. Thus, all four individual voices sound (modulo splits and layers) when a note is struck on the Korg Microkey Air. In order to set volume and pan levels, one taps the slider icon in the upper middle part of the screen. When mix is enabled, each part box shows a volume and pan knob.

Managing the list of multis

Overall, I give the win to the SampleTank engine. Eight layers/splits is more than enough and there isn’t any need to change modes or screens in order to make voice edits.

Module Pro set lists have mo’ power, however. You can attach audio songs, PDFs and other performance aids to a set list entry. I find the iPad screen too small for most of my charts, so I’m not taking advantage of those particular set list features. Access to performance aids might tip things toward Module Pro, if that’s your thing.

Copyright © 2021 Paul J. Drongowski

Korg Module Pro for church

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Over the last several weeks, I’ve been practicing and playing through church tunes. Our liturgical group covers genres from pop, light rock, classical and traditional hymns to gospel. I’m trying to keep up my chops while our group awaits its post-pandemic return.

This has been a good opportunity to wring out any issues with Korg Module Pro (on Apple iPad) and a Korg Microkey Air 49 controller. Both Korg products have been solid and I feel comfortable with the idea of using this combo live in church.

I’ve also been able to evaluate the suitability of Korg Module for our church repertoire. Module’s set-list features are very easy to work letting me build quick-access layers and splits. Set-list features are well thought out and I strongly recommend purchasing the Module Performance Expansion.

Thankfully, set-list combis store patch and effect edit, allowing me to dial in a consistent level across combis and to tweak attack, release and reverb. Just don’t forgot to save the set-list after making edits!

Right off the top, I’m quite happy with Module’s stock Hammond organ sounds. My three favorite patches are Gospel Organ, Simple Organ and Clean Organ. Church music doesn’t require over-the-top distortion. The Korg rotary speaker simulation is very good and the speed transitions (ramps) are realistic — a vital component for gospel music.

The only thing missing organ-wise is a traditional church organ. I have not purchased the Korg Organ and Clav Collection which offers a classic organ. I intend to buy the organ expansion during the next Korg app sale. In the meantime, I’m substituting Simple or Clean organ.

As to other instruments, I need orchestral woodwinds, French horn, and strings. Compared with Miroslav Philharmonik Mobile Edition, Module Pro is a general purpose, all-rounder, not a specialist like Miroslav. The sounds are good enough for live play, but would not please a purist. Nor would they be adequate for mocking up symphonic music.

Korg offer the KA Pro Orchestral Dreams expansion. “KA Pro”, by the way, means Kurt Adler Productions, who sell a full range of orchestral samples. If Korg Module isn’t to your taste, the KA Pro samples are available in the CrudeByte iSymphonic Orchestra (iPad) app. Orchestral Dreams is comprised mainly of full orchestra emulations. The emulations implement multiple velocity levels including percussion. Full orchestra emulations are not suitable for our repertoire (especially the percussion!) and I don’t plan to buy this expansion.

The Korg sounds make for good layers. The Woodwind Ensemble patch is serviceable by itself, but is fuller and warmer when layered with the Horn Ensemble voice. Same for the Solo Flute. By itself, the Solo Flute resembles a Mellotron flute, especially when playing chords or clusters. Horn Ensemble knocks down the tron-y flavor.

Here’s a quick list of my favorite patches: Wind Ensemble, Horn Ensemble, Synth Horn, Romantique Strings, Strings Pad, Solo Flute.

What’s missing? Module has solo violin and cello, but it’s missing most other solo orchestral instruments (including essential double reeds). The violin and cello voices have hard attacks and a lot of bow — difficult to tame. Thus, overall playing is limited to mainly ensemble or pad-like voices. Quite the shame. Korg need to add an orchestral expansion with solo instruments and/or small sections a la Miroslav.

Yes, I auditioned the Triton expansion pack. Having owned a Triton Taktile 49, I’m not satisfied with the Triton orchestral voices, solo voices, in particular. That’s why the Triton Taktile is gone, gone, gone.

Oddly, I have not found a simple synth pad among the plethora of synth patches. I want something very light and plain for layering — a non-fat synth pad without sweeps, sparkles and other tricks.

Functionally, I wish layers could cross-fade (“tilt”) across the keyboard. This would let us overlap (cross-fade) the upper and lower instruments forming a soft split. Hard split points are rather jarring when a right- or left-hand line needs just a note or two past the split point. Examples include Oboe/Bassoon or Oboe/Cello splits where a short blend across the split point is highly desired for continuity.

Overall, Korg Module Pro is a solid, reliable citizen within its limitations. Module is intended to appeal to and serve a wide range of users. If you need good electric piano or high-quality acoustic piano, it’s got ’em, too. I stand by my earlier positive recommendation.

Check out these related blog posts:

Copyright © 2021 Paul J. Drongowski

Review: Future Kit FK651 stereo simulator

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The Yamaha PSS-A50 is strictly MONO OUT and needs a little spice. After trying the Haas effect via a Synthrotek Dev Delay, I ordered a Future Kit FK651 Stereo Simulator. Future Kit — also known as “Thai Kits” — offers a range of audio kits including the FK651. I ordered through Amazon with Future Kit in Thailand handling fulfillment. Thanks to the pandemic and global shipping delays, I finally received the FK651 after a few weeks of waiting. Can’t blame Future Kits for the delay. They shipped right away putting the FK651 on the proverbial “slow boat from Thailand.” Thanks, pandemic!

Future Kit FK651 Stereo Simulator (click to enlarge)

The FK651 takes a MONO signal, splits it, and sends each side into a short filter chain. The left and right filter chains have different peak frequencies:

    Right channel 
    ------------- 
        32Hz  (Note C1) 
        500Hz (Note C5) 
        2kHz  (Note C7) 
    Left channel 
    ------------- 
        64Hz  (Note C2) 
        1kHz  (Note C6) 
        4kHz  (Note C8)

The filter chains alter each side of the stereo pair just enough to create the impression of different source signals coming from the right and left channels.

Kit of parts

The FK651 kit is fairly small making it suitable as a PSS-A50 mod. The small board should fit easily within the PSS-A50 even with the A50’s rather large speaker. I tested the FK651 with a 9V battery and it worked well even though 9V is below the suggested 12V supply voltage. I’m hoping to tap power from the A50’s 6V battery supply. Fingers crossed.

Why order one when you can have two?

You’re not seeing double in the picture above. I ordered two FK651 kits. By the time I paid for one kit and shipping, it wasn’t much more to order two just in case I blew up a kit. It’s happened to me before, e.g., horribly destroying a Blokas MIDIboy during assembly.

Part and board quality are good.

Assembly

Assembly is straightforward. Given the number of parts, I assembled the kit in four phases:

  1. Resistors
  2. IC sockets and quad op amps
  3. Capacitors
  4. Wiring

Due to the placement of the power and audio pads, I couldn’t use terminal blocks. I decided not to use the enclosed terminal pins and soldered external connections directly to the printed circuit board (PCB).

Future Kit FK651 Stereo Simulator (assembled)

There were two minor concerns. Although the printed directions are OK, the instructions do not include a resistor color code chart. If you decide to build an FK651 of your own, here’s my look-up chart.

Ohms       Resistor color code 
----       ------------------------ 
220        Red    - Red    - Brown 
470        Yellow - Violet - Brown 
1K         Brown  - Black  - Red 
2K         Red    - Black  - Red 
4.7K       Yellow - Violet - Red 
15K        Brown  - Green  - Orange 
47K        Yellow - Violet - Orange 
56K        Green  - Blue   - Orange 
100K       Brown  - Black  - Yellow 
470K       Yellow - Violet - Yellow

The second concern is a single inconsistency between the parts provided, the schematic, and a silk-screened legend on the PCB. [Does anybody use silk-screening anymore?] I found a 4.7K resistor when the PCB called for a 47K resistor. The part placement picture on the paper instructions has it right — “4K7”, the alternative way of writing “4.7K”. The PCB legend says “47K” and is wrong. Otherwise, it’s all pick, place and solder assembly.

The picture above shows the completed board ready for testing. The audio wires come out to 3.5mm jacks with ring, sleeve, tip (RST) terminal blocks. This should make it easy to reconfigure the FK651 during bench experiments.

The power cabling may look unnecessarily complicated, but I decided to experiment in preparation for possible integration with the PSS-A50. The JST connectors should make for plug and play with the A50. The power wires solder into a tiny “distribution board” that I nibbled out of an old proto-board. The result is a tad ugly.

Use

Power up and the FK651 works the first time. 🙂

As to testing, perceived effect depends upon source material. I had reasonable success with a drum loop (WAV demo). The first half of the demo is the direct A50 audio and the second half is FK651 simulated stereo.

I applied the FK651 to a full mix (WAV demo). Again, the first half of the demo (about 10 seconds) is the direct A50 audio and the second half is simulated stereo. With the full mix, there is a clear difference between direct and effected. Whether it’s a stereo effect or not is subjective.

Clearly, the FK651 messes with the distribution of energy across the frequency spectrum. The effected full mix demo audio has less bass. As it is, the FK651 has a profound effect on a mix, maybe an unwanted effect that undoes your hard work balancing and mixing. The FK651 may be best applied to individual instruments, not a full mix.

Full mix direct and effected spectrum (click to enlarge)

I experimented with ways to visualize the FK651 at work. Here is a false-color spectral plot for the full mix demo. The left and right channel plots are identical during the first half when the right and left channels each carry the same signal. During the second half of the demo, the right and left plots show differences due to the different filter chains applied to the left and right signals, respectively.

As to signal gain, boy, there is an abundance of gain! The A50 line OUT is the headphone OUT, which itself is a fairly hot signal. The FK651 adds even more gain. I had to attenuate source signals heavily in order to sample cleanly without distortion. I also had to carefully balance the level of the first and second halves of the demo to avoid the “louder is better” bias of human hearing.

There are still a few more experiments to try. First, it might be helpful to mix a little of the original source signal into both the right and left channels as a way to mitigate loss in specific frequency bands. This may also be a way to control the depth of the simulated stereo effect (dry plus wet). Another trick to try is putting delay on one of the outgoing channels to enhance the Haas effect.

All in all, the Future Kit FK651 Stereo Simulator is an easy build and a fun toy (tool). It’s not a be all or end all solution. The Volca Mix stereo spread effect beats the FK651 hands-down. The FK651, however, is small and inexpensive enough to deploy in a circuit mod as long as you can tame its gain.

Copyright © 2021 Paul J. Drongowski

Review: Synthrotek Dev Delay

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I’d like to add more animation to the distinctly sound of the Yamaha PSS-A50. I really like the Korg Volca Mix stereo width effect and want to add something similar as either a mod or an external effect.

My intuition suggests the Haas effect or as Wikipedia would have it, the precedence effect. This well-known effect delays one side of a stereo pair that changes our perception of a sound source in the stereo field.

Rather than buying — and potentially, disassembling — a delay effect pedal, I decided to give the Synthrotek Dev Delay kit a try. Synthrotek offer a broad range of inexpensive kits and heck, they’re located nearby in the Pacific Northwest!

Synthrotek PT2399 Dev Delay — It’s in the bag

The kit is a relatively straightforward implementation of a PT2399 delay — right off the datasheet. The Princeton Technology PT2399 is a workhorse appearing in many guitar pedals, synth modules, karaoke mixers, etc. The VCO control voltage (pin 6) determines the delay time and is set by a 50K linear potentiometer. The delayed signal is fed back into the input with feedback level set by a second 50K linear potentiometer. In addition to the PT2399 and its discrete minions (resistors and capacitors), there is an LM78L05 +5V power regulator.

Synthrotek Dev Delay — Parts is parts

Synthrotek provide a rather nice board and kit of parts. It includes many unexpected extras: both 3.5mm and 1/4″ phone jacks, knobs, switches, power LED and parts needed for PT2399 mods. Quite decent of them! My only niggle is the quality of the potentiometers. Physically, they appear dingy and functionally they are a little noisy. I would call them “surplus grade.” If building the finished kit into a permanent project like a pedal, I would replace the pots with fresher parts. Please don’t let this concern stop you from buying a kit, however.

Synthrotek Dev Delay — Almost finished

The kit builds quickly enough. For some crazy reason, I had trouble keeping my soldering tip clean. Once I got some flux from Lowes (desperation!), soldering went better. Maybe it’s my eyes, but even the DIP and standard size discretes seem smaller and smaller…

I like reconfigurable builds that are easily re-purposed. So, I added a number of embellishments. I added two three-contact terminal blocks (5mm pitch) for the pots on the PCB. The terminals match up with the potentiometers’ leads and since the pots are linear, I flipped them around and connected them to the terminal blocks directly. I don’t think you can play this trick with log pots, by the way.

Synthrotek PT2399 Dev Delay — Assembled with enhancements

I added a JST connector for battery connections. Audio in and out wires are soldered directly to the PCB. The other end of the audio wires are connected to 3.5mm jacks with in-built terminal blocks for ring, tip and sleeve. These audio jacks are very handy and I intend to use more of them in the future. They have a shaft and nut for panel mounting, making them suitable for permanent installation, not just prototying.

Connect a battery…

… and nothing.

This is the moment which we builders all dread.

Drag out the digital multi-meter (DMM). Power is good to the board. Audio wires are good to the board. Crank up the volume on the powered speaker and a faint signal is heard.

So, what’s up? Check the connections to the audio jacks and, holy smokes! Instead of signal to tip (T) and ground to sleeve (S), I have ground to ring (R). I didn’t pay close enough attention to the terminal order and labels.

After a quick fix, the Dev Delay was up and running. I used the PSS-A50 as my signal source and had it play a drum pattern over and over. Yes, you can get King Tubby with this unit!

My experiments with the Haas effect, however, were less exciting — too subtle for my taste. I noticed that the Korg Volca Mix does not use an analog or digital delay circuit. Thus, my search for a stereo animator goes on. I have a Thai Kits (Future Kit) FK651 stereo simulator in hand and will try it next.

As to the Synthrotek Dev Delay kit, if you need a digital delay in kit form, give it a go! Great for audio innovators.

Copyright © 2021 Paul J. Drongowski

Steinberg WaveLab Cast bundle

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This deal is too good to go unnoticed. If you bought a Yamaha AG03 or AG06 mixing interface, I hope you saved (or used) the Cubase AI download access code. It’s your ticket to a free copy of Steinberg Wavelab Cast.

Yamaha added Wavelab Cast to the AG series software bundle during August 2021. You can download and activate WaveLab Cast even if you are an existing customer.

Fortunately, I’m a pack-rat and saved all the paperwork with the AG06. Wavelab Cast looks to be a fast way to touch up live recordings among other uses. The Track Inspector offers a menu of the most common audio tune-ups: denoise, de-ess, EQ, reverb, etc., featuring no-brainer one-knob control.

My only wish is a written (PDF) getting started guide. The PDF manual is a reference manual and isn’t organized well for getting started. At a minimum, a beginner user needs to know about the “Audio Montage” and how to get audio clips into the Audio Montage pane. Audio Montage isn’t discussed until Chapter 10! Also, one should know that the audio editor mainly twiddles bits (errr, samples) and that effects are applied through Audio Montage.

Please don’t let these quibbles slow your roll to a free copy.

I’ve been using the Yamaha AG06 as my desktop mixer and audio interface. It has performed reliably over the past several months and I feel comfortable recommending it even though the internal tech is a little bit behind the Steinberg UR22c (its closest alternative in the Steinberg product line). I like the small mixer format and the audio I/O options. Plus, the AG06 has been dead quiet when attached via USB to an HP desktop computer and its schmutzy (noisy) power. The AG06 has a separate 5V external power port for mobile operation, too.

Cash in!

Copyright © 2021 Paul J. Drongowski

Wire Less: Part 2, Belkin RockStar™

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Well, as you might have guessed, your Apple iPad synthesis rig cannot be entirely wireless (at least inexpensively so). The audio part ain’t there yet. Bluetooth audio has too much latency and Apple does not provide any other built-in solution. So, it’s wires, again, folks.

In my first post, I discussed the MIDI part: an Apple iPad running Korg Module Pro communicating with a Korg Microkey Air 49 over MIDI BLE. The MIDI part works quite well and I haven’t had any issues.

As to the audio part, I absolutely detest the iPad 3.5mm phone connector. Any plug is exposed and even the slightest movement emits a nasty grind from a powered speaker or other downstream audio device. Buzzzzzz — literally. I simply wouldn’t risk this method in a high volume situation in front of a church congregation.

The Lightning connector, however, is relatively snug and secure. Like most people, I opt for a Lightning-based solution. With Bluetooth handling MIDI duties, one needs only an audio interfacing solution.

Sorry, USB-C people, I don’t have a USB-C iPad and don’t address USB-C solutions here.

By now, everyone knows that the Apple Lightning to USB Camera Adapter is not just for cameras. Thanks to the Camera Adapter, you can hook up a USB-based audio interface to your iPad (or iPhone). The Camera Adapter’s street price has dipped to $9USD, making this a very inexpensive solution. If — if — your bus-powered audio interface draws a small amount of power, the Camera Adapter will supply power although the iPad battery drains faster. If your bus-powered audio interface is a power hog, you will get the infamous “This accessory requires too much power” message and iPad will refuse to play along, shutting down the interface.

Enter the Apple Apple Lightning to USB3 Camera Adapter ($39USD). The USB3 Camera Adapter has two ports: a USB3 host port and a Lightning charge port. The USB3 port connects to your audio interface while the Lightning port connects to an AC adapter. The Lightning port both charges the iPad battery and supplies power to your audio interface.

At one time, I considered the Steinberg UR22C as a solution for both desktop use and mobile. The UR22C has the necessary functional features and sports its own external power port. This is definitely another way to go and I wish more manufacturers would provide an external power port and not rely solely on bus power. I decided to eschew “yet another box at the gig” in favor of an even smaller, lighter solution. (For desktop, I eventually chose the Yamaha AG06, BTW).

Belkin adapter and the tangled mess o’cables

For smaller and lighter, I went with the somewhat neglected Belkin 3.5mm Audio + Charge RockStar™ ($40). This Belkin adapter provides a more robust 3.5mm jack and a Lightning charge port. My only beef is the short iPad to adapter Lightning cable. The short cable is good enough for casual listeners, but I feel that it still requires too much stress on the 3.5mm jack. I added a 2 meter Lightning extension cable, letting me rest the adapter and 3.5mm plug on the floor. This arrangement reduces the physical stress on the iPad Lightning port, too. One flexible cable to the iPad makes it easier and safer to move the iPad during a gig.

A few fine points. I configure Korg Module Pro for MONO out and use a 3.5mm stereo to 1/4″ breakout cable (tip and ring) for the final audio connection. MONO is close enough for rock’n’roll. I realize this is audio religion to purists. 🙂

If you don’t want 3.5mm audio, Belkin offers the Belkin Lightning Audio + Charge RockStar™ ($45USD). It has a two Lightning ports: one for audio and one for charge.

Before closing, I want to mention an ultra-cheap, simple solution: an Apple Lightning to 3.5mm Headphone Jack Adapter plus an extension cable. You may already have one of these adapters! When Apple dropped the 3.5mm jack, it began selling these adapters so people could connect their headphones to the jackless iPhone. It’s ultra-inexpensive at $8USD (street).

Check out these related blog posts:

Copyright © 2021 Paul J. Drongowski

Random answer day (1)

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Maybe it’s the first day of the regular NFL season or the phase of the moon. Here’s a recap of a few questions that came into the forums.

How are arranger/synth preset voices stored? First, one may ask, “How is a preset represented?” Typically, a preset voice consists of waveforms (AKA “samples”) and voice (meta-)data. The voice data control how the sample-playback engine applies filtering, amplitude envelope, modulation and so forth. The waveforms, of course, provide the basic digital audio data.

There is such a broad range of arranger/synth products at different price points, that the amount of storage and the kind of storage varies quite a lot.

The lowest of the low in the Yamaha range: PSS-A50, -E30, -F30, PSR-F51. Presets are stored on a 2MByte serial flash ROM and are loaded into the processor (SWLL) at start-up. The 2MBytes include code, too! Tone generation is integrated into the SWLL. Insanely small, and very low cost.

The highest of the high in the Yamaha range: Genos. Factory presets are stored in four 1GByte ONFI NAND flash devices. Expansion memory consists of two 1GByte ONFI NAND flash devices. Wave memory connects directly to external tone generators (SWP70).

I’ve looked at the diagrams for Genos and I’m not sure about the size and function of those memory units, especially Genos USER memory and expansion memory.

Yamaha confuses people when they speak of “user memory,” “internal memory,” etc. They are usually referring to logical, user visible storage.

When getting down to the hardware level, there are many different physical memory units. since we’re not discussing fairy dust or magic, the logical storage must be assigned to one or more physical memory units. And, of course, the physical memory units themselves may be composed of multiple integrated circuits. The other dimension is “what communicates to what.” Memory is passive and needs a processor to initiate reads and writes and to do something with all that data. At the physical level, a memory unit essentially belongs to a single processing unit (host computer, tone generator) and directly communicate with it.

Sometimes I think of the SWP70 as a parallel processor just like a GPU. The CPU/SWP70 is not exactly analogous to host CPU plus GPU, however. Graphics memory is shared between CPU and GPU. The SWP70 does not share its waveform memory with anybody — it’s dedicated to the tone generator. That’s why installing an expansion pack (voice library) is kind of slow and technically complicated, and why a Genos reboot is required.

Yamaha Genos SWP70 tone generators

Staying with Genos, Genos has two SWP70 tone generators: one handles factory presets and the other handles user expansion voices. The factory SWP70 has 4GBytes of flash memory while the expansion flash memory has 1GB of flash memory. That’s physical memory. Yamaha boosted the effective capacity to 3GB expansion through compression.

The SWP70s also have DSP RAM. As a user, you never know about this memory. It’s scratchpad memory for DSP effects. Physically, the DSP RAM is completely separate and independent from the waveform memory, and communicates with only its parent SWP70.

Yamaha Genos Host CPU

The host CPU has two kinds of memory (as determined by its bus interfaces): 1GB of working RAM on the CPU memory bus (EMIF) and two embedded eMMC memory devices that act like solid state storage drives (MMC0 and MMC1). As far as a user is concerned, the user never sees the 4GB eMMC drive (MMC0) just like you don’t see the DSP RAM; it’s hidden. The MMC0 drive contains the Linux operating system kernel and the root file system.

The user sees only part of the second 64GB eMMC drive (MMC1). The user sees the logical storage which Yamaha calls “Internal memory” or “USER drive.” What’s in the remaining 6GB? I don’t know — Yamaha haven’t left any clues.

What about Montage and its 5.67GByte waveform memory? 5.67GB is the capacity when the waveforms (samples) are compressed. Again, this is logical storage capacity.

Yamaha Montage SWP70 tone generators

Montage has two SWP70s. One SWP70 is dedicated to FM-X and it does not have waveform memory. The second SWP70 handles AWM2 synthesis (sample playback) and has waveform memory connected to it. The waveform memory consists of four 1GByte devices totaling 4GBytes. Thanks to Yamaha’s proprietary compression, Montage stores 5.67GBytes-worth of data in the physical waveform memory. The remaining space, 1.75GB physical, is available for user samples.

How does sample capacity relate to price? It doesn’t. Component cost is outweighed by manufacturing costs, software development cost and sound design cost.

If the memory components are so cheap, why isn’t there more waveform memory? If there was more, then you wouldn’t buy the Mark II model, would you? 🙂

I understand that E30/F30 do NOT offer velocity sensitivity. My question is about the internals. Is it confirmed that it’s a keybed with two switches per key, that just aren’t supported in software?

Yes, you need to be careful here. There are hardware model differences: E30 and F30 are not velocity sensitive. A50 is velocity sensitive.

There are two different keybed printed circuit boards (PCB). Yamaha part number VAY27800 for F30/E30 and VAY28500 for A50. The A50 PCB has the necessary diodes installed for velocity sense. The F30/E30 PCB does not have the diodes. Further, the A50 board has a 12-pin connector while the F30/E30 board has an 11-pin connector — perhaps to avoid assembly mistakes.

Yamaha Reface key switch matrix schematic

Is velocity sense worth the extra bucks? There may be other differences, too, but these differences are plainly visible.

And the usual caution/disclaimer — kiss the warranty good-bye! For the money, the PSS should be good mod-fodder. Korg probably sold a mess o’monotron that way. 

Copyright © 2021 Paul J. Drongowski

Wire Less: Part 1, Korg Microkey Air 49

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With the pandemic raging, I’m searching for ways to reduce my physical gig footprint and schlep factor. I thought I would share my adventure in battery-lowered, almost wireless keyboard-land.

Months ago, I had a good experience with Korg Module Pro. It has the range of high quality sounds that I need for my church gig. So, I decided to eschew battery-powered MIDI modules like the MidiPLUS miniEngine USB and go iPad and Korg Module Pro.

Yamaha SHS-500 Sonogenic (labels added)

I tried a bunch of controller candidates. (See the end of this post for more info.) I had the best experience and minimal number of wires with built-in Bluetooth MIDI. The SHS-500 Sonogenic, in particular, is nearly ideal:

  • Pluses: Built-in Bluetooth, pitch bend and mod wheels, decent mini-keys, narrow depth is good for a lap-board.
  • Estimated battery life is OK (10 hours); AC adapter jack is well-placed and secure.
  • Minuses: 37 keys (3 octaves), no expression pedal input, mod wheel works backwards when played in one’s lap.

No, I am not playing the SHS-500 as a keytar. I find the whole keytar thing to be gimmicky and not appropriate for church. I intend to play the controller in my lap, thereby keeping my physical profile small. (Social distancing!) A lap-board lets me ditch the keyboard stand, minimizing schlep.

Mini-keys deserve comment. Mini-keys enable short, lap-held keyboards. They are very lightweight and easy to transport. If the basic key feel is good, I make peace with play-ability.

My trouble isn’t so much with key size. It’s that three octaves (37 keys) are too short. Many melody and bass lines require two octaves and a player needs two octaves below middle C and two octaves above. Otherwise, I do unnecessary mental and hand gymnastics in real-time to fit the music onto the keyboard. That ain’t right.

Just me? Watch Harry Connick Jr. rock a 3 octave Reface CP. Harry sez, “There’s not a lot of room here.” [Tonight Show: Jimmy Fallon, NBC, 1 September 2016, Playing starts at 3:00.]

Korg Microkey Air 49

In the end, I broke down and bought a Korg Microkey Air 49. It is a good size for a lap-board and the Korg Natural Touch mini-keys ain’t too bad. The Microkey Air firmware was already at v1.04 when it arrived and it connected with Korg Module Pro under IOS 14.1 without a problem. [More on this in a future post.]

The Microkey Air 49 has an estimated 30 hour battery life. Good thing, because Bluetooth operation must use battery power (two AA batteries). Be sure to have two spare AA batteries at the gig; there isn’t a USB powered safety net.

The Microkey Air has a footswitch input. Expression input would be better. Of course, connecting a pedal to the Microkey Air adds a cable. Fortunately, Bluetooth pedals like the Airturn BT200-S4 get the job done. I have a BT200-S4 and found it easy to switch sustain, etc. via Bluetooth in Korg Module Pro. The BT200-S4 is small and light, not any worse than schlepping a wired sustain pedal.

I made a few advances with iPad wiring along the way. The Korg Microkey Air 49 is working out pretty well and I’m practicing with it every day. I have a few custom layers in Korg Module Pro and the day is coming when I’ll try out the rig in front of a congregation.

Going native

For completeness sake, I tried “going native” with sounds built into the Yamaha SHS-500 Sonogenic, Yamaha Reface YC, Yamaha PSS-A50 and Korg microKorg XL+ — all fine battery-powered instruments in their own right with sounds appropriate for rock, soul, jazz, and pop, but not church. I need good strings, reeds, classic organ and gospel B-3. Before moving on, I give props to the Reface YC as it is truly gig-worthy and have play it on the job.

Blooming BLU

I also tried using “the natives” as Bluetooth MIDI controllers. All of the candidates have USB and/or 5-pin MIDI DIN ports, and can be fitted with Yamaha UD-BT01 and MD-BT01 wireless MIDI adapters. The candidate keyboards are battery-powered, so what the heck!

Yamaha UD-BT01 (with AC adapter) and UD-BT01 Bluetooth MIDI

To make a long story short, all candidates worked well with the Yamaha adapters and with Korg Module Pro on iPad — even the lowly, dirt-cheap PSS-A50. A few specific observations:

  • The Yamaha UB-BT01 not only does Bluetooth MIDI, it supplies power to the PSS-A50. If you must add a cable to connect the A50 to the UD-BT01, you might as well get power, too, and save batteries. If you own a PSS-A50 and want to go Bluetooth MIDI, don’t hesitate!
  • The Reface YC has the added bonus of an expression pedal input. An expression pedal is a vital part of my gig toolkit. Korg Module Pro will connect simultaneously to more than one Bluetooth MIDI source (like the BT200-S4 previously mentioned). In one experiment, I used Reface YC as my expression source while playing the black and whites on the SHS-500. Neat. I might add the new Boss EV-1-L wireless expression pedal once it ships.
  • I looked into expected battery life. The Korg Microkey Air is the best at 30 hours estimated life. The other solutions are burdened by tone generation and DSP. The added power-burn is unnecessary if we’re not using the internal synthesis engines.

Even though you take a power hit, an internal engine is a good back-up in case there is a technical problem with Bluetooth, the iPad or Module Pro.

    Instrument     Estimated battery life 
    -------------  ---------------------- 
    Microkey Air          30 Hours 
    PSS-A50               20 Hours 
    SHS-500               10 Hours 
    Reface YC              5 Hours 
    microKorg XL+          4 Hours

In terms of key feel and play-ability, all candidates are acceptable. The Yamaha HD mini-keys are more synth- and organ-like, and are good for legato (especially organ). The Korg Natural Touch mini-keys are more piano-like — good for striking, not quite as good as Yamaha HD for legato. Unlike Microkey Air 49, the other candidates are 37 keys and are too short for unfettered play.

                           Key dimensions 
                        -------------------- 
    Instrument          Width  Length  Depth 
    ------------------  -----  ------  ----- 
    Reface HD            19mm    88mm    9mm 
    Korg Natural Touch   20mm    80mm    8mm 
    MODX                 21mm   133mm   10mm 
    Genos FSX            22mm   133mm   10mm

Check out these related blog posts:

Copyright © 2021 Paul J. Drongowski

PSS chorus: A dusty look back

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Here’s a look into the past — and maybe, the present.

A PSR Tutorial Forum member inquired about the chorus effects in the PSR-E463. The PSR-E463 has the usual system chorus effect and the newer DSP chorus effect. I’m going to focus on the older system chorus effect.

The PSR-E series chorus system effect date back to the earliest days of Yamaha XG and arranger keyboards. These are low-cost entry-level keyboards and usually contain a single integrated circuit (IC) which integrates the main processor (CPU), tone generator and effect units. The most price- and cost-sensitive models integrate the wave memory (samples) on the IC, e.g., the SWLL (PSR-F51). Processors in the other models have an external wave memory, e.g., the SWL01 (PSR-E443) and SWX03 (PSR-E463).

Newer DSP effects aside, the E-series models share the same basic reverb and chorus effects. There are three chorus effects:

  • Chorus1 (MSB: 66 LSB: 17)
  • Chorus2 (MSB: 65 LSB: 02)
  • Chorus3 (MSB: 65 LSB: 00)

The LSB has varied, but they all refer to the same CHORUS (CELESTE) effect algorithm. The LSB just selects a set of preset effect parameters. Chorus1, BTW, falls into the XG CELESTE category, not CHORUS.

Due to hardware integration, the chorus effects likely share the same hardware. Since none of these processors have external DSP RAM, the chorus memory is integrated, too.

As far as chorus is concerned, this is the way it has been since the 1990s! Let’s look back to the Yamaha QY-70 XG implementation (1995). I suspect that the current chorus effects are the same or very similar to the good old QY.

The QY-70 had one chorus and celeste effect algorithm:

Param#  Parameter            Value range 
------  -------------------  -------------------- 
   1    LFO Frequency        0.00Hz - 39.7Hz 
   2    LFO PM Depth         0 - 127 
   3    Feedback Level       -63 - +63 
   4    Delay Offset         0 - 127 
   5 
   6    EQ Low Frequency     50Hz - 2kHz 
   7    EQ Low Gain          -12dB - +12dB 
   8    EQ High Frequency    500Hz - 16.0kHz 
   9    EQ High Gain         -12dB - +12dB 
  10    Dry/Wet              D63;gt;W - D=W - D<W63 
  11    ... 
  15    Input Mode           Mono, Stereo 
  16

These parameters are laid down by the Yamaha XG specification.

The XG specification does not define the preset values, however. Here are the QY-70 preset chorus values:

Param#  Parameter            Chorus1 Chorus2 Chorus3 Chorus4 
------  -------------------  ------- ------- ------- ------- 
   1    LFO Frequency        0.25Hz  0.33Hz  0.16Hz  0.37Hz 
   2    LFO PM Depth         54      63      44      32 
   3    Feedback Level       +13     +0      +0      +5 
   4    Delay Offset         106     30      110     104

QY-70 Chorus3 has the same MSB/LSB as PSR-E Chorus2. QY-70 Chorus 1 has the same MSB/LSB as PSR-E Chorus3. Confusing? Yes, but these are probably the PSR values or close to it.

Next are the QY-70 preset celeste values:

Param#  Parameter            Celeste1 Celeste2 Celeste3 Celeste4 
------  -------------------  -------- -------- -------- -------- 
   1    LFO Frequency        0.50Hz   1.17Hz   0.16Hz   0.33Hz 
   2    LFO PM Depth         32       18       63       29 
   3    Feedback Level       +0       +26      -20      +0 
   4    Delay Offset         0        2        2        0

None of the QY-70 presets have the same MSB/LSB as PSR, so your guess is as good as mine.

Now, the really bad news. The PSR-E series, at best, is XGlite. XGlite implementations typically don’t support the XG messages that set effect parameters. Therefore, what you hear is that you get. In other words, the effect presets are hardwired.

The Yamaha PSS series with its minimal SWLL processor implements exactly one chorus and exactly one reverb preset. You get what you pay for!

Copyright © 2021 Paul J. Drongowski

PSS-A50 MIDI mod

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Sometimes you get very lucky when searching the Web!

A Japanese blogger (darekasan_net) posted a review of the Yamaha PSS-A50 and a mod adding 5-pin MIDI OUT. [Google translation of the review]

There are a set of test pads in the upper left corner of the A50 main board (DM) as shown in the picture below. [Click image to enlarge it.]

Yamaha PSS-A40 MIDI signals and USB circuitry

The two larger rectangular pads (orange) are digital ground (DGND). The four smaller pads (blue) from left to right are:

  1. MIDI_IN (RXD MIDI_IN)
  2. MIDI_OUT (TXD MIDI_OUT)
  3. 3.3V
  4. Digital ground

The blogger connected the MIDI_OUT signal to a 5-pin DIN connector, which is mounted nearby on the enclosure.

By the way, Yamaha conveniently mark test points with a circle (bullseye). You can see several test points for digital ground (DGND), the +3.3V digital rail, and the +5V digital rail. The USB interface chip is an NXP ARM microprocessor. The micro USB connector is in the upper right.

Direct connection is too trusting. The MIDI_IN and MIDI_OUT pads go directly to SWLL pin 55 (RXD) and SWLL pin 54 (TXD). I suggest adding a 220 ohm current limiting resistor in series with MIDI_OUT. Adding a signal buffer would be even better since you would rather blow up the buffer instead of the main processor (YMW830-V or SWLL) should someone radically misconnect the 5-pin MIDI port. A current limiting resistor on the +V MIDI pin wouldn’t hurt either.

Simple MIDI OUT circuit

If you get the urge to add 5-pin MIDI IN, you’ll need an optoisolator as shown in the schematic below.

Simple MIDI IN circuit

Although the schematics indicate 5V, the circuits should work with 3.3V instead. Fortunately, the unpopulated test connector provides +3.3V as well as MIDI_IN and MIDI_OUT.

Here’s an idea. Instead of hacking in a 5-pin DIN connector alone, why not add a Bluetooth MIDI plug like the CME WIDI Master?

Our Japanese blogger considered adding a sustain input. The PSR-F50 dedicates SWLL pin 53 (PORTC0) to sustain. Unfortunately, the PSS-A50 has other ideas and SWLL pin 53 mutes the headphone output instead. You could put an external switch in parallel with the front panel sustain switch, but it toggles sustain and, thus, it doesn’t behave like a true piano sustain pedal.

As with any mods, make them at your own risk and kiss your warranty good-bye!

Copyright © 2021 Paul J. Drongowski