Category Archives: Music technology

Keystep for littleBits

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My last blog post took a look at the Pitch and Gate control voltages (CV) generated by the Arturia Keystep. Keystep’s Pitch and Gate behave conventionally. I also took note of how they differ from the littleBits gate CV signal, which combines pitch and gate control into a single signal. I mentioned two potential approaches for interfacing Keystep to littleBits:

  • Driving littleBits with Keystep’s Pitch and Gate, and
  • Sending MIDI to a littleBits MIDI module that handles conversion to littleBits gated CV.

I tried each approach. Here’s what I learned.

Keystep Pitch and Gate circuit

In this approach, the littleBits Oscillator is always running, always generating an audio signal. The Oscillator tracks the Gate voltage generated by the Keystep. The trick is opening up and shutting off the audio signal. For that, I put a littleBite Envelope module after the Oscillator and triggered the Envelope with the Keystep Gate voltage.

The resulting circuit is:

            Keystep Pitch                Keystep Gate 
                  |                           | 
                  V                           V 
    Power --> CV Module --> Oscillator --> Envelope --> Speaker

The Keystep Pitch output is connected to the “CV IN” connector on the CV Module. The CV Module routes the incoming control voltage to its output, which sends the pitch control voltage to the Oscillator Module. The Keystep Gate output is connected to the Envelop’s Trigger input.

littleBits Proto Module ins and outs
littleBits Proto Module and quick-and-dirty patch cable

The Pitch output to CV IN connection is a standard 3.5mm patch cable. But, how is the 3.5mm Gate jack connected to the Trigger bitSnap? The littleBits Proto Module provides the solution. I cut a (stereo) patch cable in two and connected the shield and tip wires to the littleBits Proto Module as shown above. The Proto Module sends the incoming trigger signal (the Keystep Gate) to the output bitSnap. From the output bitSnap, the trigger signal goes to the Envelope Trigger input.

Properly, I should have used a mono patch cable, but I didn’t have one to sacrifice. I connected the TIP and SHIELD wires, leaving the RING unconnected.

That’s the entire setup! For testing purposes, I attached oscilloscope probes to the trigger (Keystep Gate) and the Envelope’s audio output. I also verified correct operation at intermediate points along the main signal path.

Oscillator audio (top) and Keystep Gate (bottom)

The screenshot above shows two oscilloscope traces. The top trace (green) is the final audio signal. Note the attack-release envelope around the oscillator signal. The bottom trace (red) is the trigger (Keystep Gate) signal. If the trigger is dropped before the entire envelop completes, the audio cuts off (i.e., it’s truncated). If the trigger is held beyond the combined attack plus release time, the audio signal merely stays at zero. The audio signal remains shut off until another trigger (the rising edge of Gate) is received.

Although this circuit gives us the desired behavior, it wasn’t easy getting things to work reliably. I seemed to suffer more than the usual loose connections and other lab-bench gremlins.

MIDI Module circuit

The MIDI Module approach is very similar to driving the littleBits Oscillator Module by MIDI over USB from a PC DAW:

           Keystep MIDI OUT 
                   | 
                   V 
    Power --> MIDI Module --> Oscillator --> Envelope --> Speaker

MIDI arrives on the MIDI Module’s 3.5mm connector instead of the USB port. Otherwise, the main signal flow is the same.

Keystep/littleBits test rig

I monitored the gated CV signal produced by the MIDI Module and the audio signal generated by the littleBits Envelope using the oscilloscope. I played two notes in quick succession. The second note is two octaves higher than the first note.

littleBits audio triggered by MIDI Module

In the screenshot above, the top oscilloscope trace is the gated CV signal. The bottom trace is the synthesized audio. Not any different than the Pitch and Gate control volltage approach, eh?

Since the final audio is much the same, I would go with the MIDI Module circuit. It is simpler and its wiring is less touchy. The circuit uses the littleBots modules pretty much as intended by the littleBits engineers.

The MIDI Module approach makes the Keystep Pitch, Gate and MOD outputs available for other duties such as key-scaling (i.e., varying the effect of a sound modifier by keyboard pitch), modulation and user control. Don’t forget to insert littleBits Dimmer Modules (potentiometers) along control paths in order to set modulation level and so forth.

Copyright © 2020 Paul J. Drongowski

Arturia Keystep CV

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My post about Arturia Keystep teardown and cleaning attracted a fair number of page views; it must have hit a common chord. 🙂

Today’s post continues with Arturia Keystep. Although the Keystep Gate and Pitch control voltage (CV) signals are conventional, I wanted to visualize them with an oscilloscope. I strongly recommend getting an oscilloscope when working in modular synthesis because pictures/graphs help understanding. [We haven’t even gotten to the audio yet!] I connected the Gabotronics Xminilab oscilloscope to the Keystep’s Gate and Pitch CV outputs and took a quick look.

First thing I noticed was a 12V positive trigger level. Holy smokes, I hope I didn’t apply that high signal to littleBits way back when! littleBits modules operate in the 0V to 5V range. Fortunately, littleBits input ports have an ON Semiconductor ESD9L5.0ST5G ESD suppressor/TVS diode, which protect against ESD and transient voltage events. Still, it’s better to configure voltages correctly ahead of time and not risk an accident.

Second thing is that Keystep CV voltages cannot be configured through its front panel. That’s somewhat understandable in a low cost product like Keystep. Control voltages are configured by Arturia’s MIDI Control Center (MCC) software — a free download for Keystep owners.

Here is the control voltage configuration that I used during testing:

  • MIDI CV output: Volt per octave
  • 0V MIDI note: C1
  • Note priority: Last
  • MOD CV source: Mod wheel
  • MOD CV max voltage: 5V
  • Pitch bend range: 2 semitones
  • Gate CV output: V-trig 5V

Keystep supports V-trigger 12V and S-trigger in addition to V-trig 5V. S-trigger is the old Moog convention that is not used very much anymore. It’s sometime called “negative trigger,” but it’s really a strange creature requiring a special connector.

Keystep Gate (green) and Pitch (red) control voltages

The screenshot above shows the Keystep in action. [Click image to enlarge.] The top trace (green) is the Gate (V-trigger 5V) output and the bottom trace (red) is the Pitch output. The Gate signal is, er, a gate. It goes high when a key is pressed, stays high while the key is held, and goes low when the key is released.

In the example, I played three notes where each note is an octave apart. The vertical oscilloscope scale is 2.56V per grid division. Each step up in the bottom trace (Pitch) is about 1V. Also, you see the Gate signal hit a maximum 5V.

In the future, I may need to tweak Keystep’s 0V MIDI note parameter if I drive the littleBits Oscillator module with the Pitch signal. One needs to find a happy operational sweet spot between Keystep octave transpose and note range versus the limited 5 octave range of the Oscillator module. Keystep’s Pitch signal ranges from 0V to 10V, and I don’t want to drive the littleBits Oscillator with more than 5V, if possible. MCC does not allow us to specify a maximum, do-not-exceed Pitch voltage.

One way around the pitch voltage issue is to control the littleBits Oscillator via the littleBits MIDI Module instead. In that case, the Keystep 5-pin MIDI OUT connects to the MIDI Module (mode switch set to IN) over a Korg convention, 5-pin to 3.5mm adapter. (The O-Coast adapter adheres to the same convention and works, too.) With the MIDI approach, we don’t need to worry about over-driving the Oscillator module with a high, out-of-range voltage. The littleBits MIDI module tops out at 5V.

I have both the littleBits MIDI module and littleBits CV module. Thus, I can drive littleBits oscillators via MIDI and send the Keystep MOD CV to the littleBits CV module for modulation duties. With the Keystep MOD CV max voltage set to 5V, I should be safe. If I need to reduce the MOD CV range further, I can always run the output from the littleBits CV module into a littleBits dimmer (potentiometer) and attenuate the level.

The MIDI module approach also produces the gated CV signal expected by littleBits oscillators. The Keystep Pitch output provides a simple, steady voltage level and doesn’t have an in-built gating function. When you hit a key, the Keystep changes the Pitch output voltage accordingly and the Keystep holds that voltage even when the key is released. If connected to a littleBits Oscillator, the Oscillator will never see a release event, that is, the Pitch voltage never drops to 0V when a the key is released. The littleBits Oscillator merrily continues to play! On the other hand in littleBits-world, the gated CV drops to zero. Thus, littleBits combines pitch control and trigger (gate) into a single signal.

One could build a simple converter from separate gate and pitch CV to the littleBits gated CV. I’m thinking of a voltage-controlled SPDT analog switch like the Texas Instruments TS5A9411 (or MAXIM MAX4544, etc.). The trigger (gate) signal controls the switch. When the trigger is low, the signal connects to ground and passes 0V. When the trigger is high, the switch passes the Pitch CV signal.

Another possible work-around is to follow the littleBits Oscillator with an Envelope module and connect the Envelope’s trigger to the Keystep Gate output through a littleBits CV module. [Whew!] The Envelope should pass and shut off the Oscillator’s sound when the gate is asserted and dropped, respectively. I’m going to give this idea a go.

Copyright © 2020 Paul J. Drongowski

Arturia Keystep tear-down and cleaning

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As part of the littleBits revival, I pulled the Arturia Keystep from storage. The Keystep has a nice keybed and sequencer, and supports a wide range of interface options: 5-pin MIDI, CV, gate, sync and USB MIDI.

Although I love its industrial design, the Keystep keys have always been somewhat unreliable. Straight out of the box, one of the keys did not trigger reliably. After moving and storage, unfortunately, several more keys became flaky or non-operational. Time to tear down and clean! [Click images to enlarge.]

Arturia Keystep wide open

I watched a Youtube video covering repair of the aftertouch ribbon. Initial disassembly is straightforward: 1. Pull off the knobs. 2. Remove the 14 large screws on the bottom. 3. Carefully open the top (white or black front panel.

Arturia Keystep aftertouch cable (connected)

The key assembly connects to the main electronics through two ribbon cables: the aftertouch cable and the key matrix cable. I marked the top side of each cable so I would know the correct cable orientation during re-assembly.

Keystep aftertouch cable (disconnected)

The aftertouch cable has a four socket connector that slides over four right angle pins on the printed circuit board. Disconnecting it is easy; just slide the connector out in the same direction as the pins. Please note the black X. That’s my mark so I know how to orient the cable when putting everything back together. This is important because there isn’t an indexing mechanism for the cable and it’s possible to insert it the wrong way.

Keystep key matrix cable (black connector tabs open)

Next, one needs to disconnect the key matrix cable. Once again, I marked the cable in order to know its correct orientation. The cable is paper thin with exposed leads at the end. I always get faked out by these newfangled PCB cable connectors. Slide the two black tabs on either side of the connector in order to release the cable. During re-assembly, you’ll insert the cable and slide the tabs to lock the cable into place.

While we’re here, that’s an ST Micro STM32F103 ARM processor which is the brains of the whole operation. Ya know, for a 100 bucks (USD), there’s a lot of technology and quality built into this thing!

After disconnecting the cables, the front panel electronics can be separated from the keybed in the metal chassis tray. Now it’s time to remove the keybed itself by removing the 10 small screws on the bottom of the tray.

Keystep key switch matrix PCB (ignore the missing keys)

Flip the keybed over and you see the key matrix PCB. The key matrix lets the ARM scan the key contacts. The tiny components are switching diodes. For the time being, ignore the missing keys (!). I’ll explain later…

Next, remove the four tiny screws holding the key matrix PCB in place. Then, carefully push back the four black plastic tabs, one at a time. Remove the PCB and flip it over.

Now you see the actual key contacts. This is the money shot. The PCB has two maze-like traces for each contact. The black dots on the rubber contact strip make two separate electrical connections on the PCB when a key is pressed. One connection is made first, followed by the second connection. The ARM software senses the connections and measures the time between contact. The software maps this time into the MIDI note velocity.

At this point, I used alcohol prep pads (70% isopropyl alcohol) to clean both the PCB traces and each of the black dots on the rubber contact strip. These are the same small pads that doctors or nurses use before a finger stick test. Be gentle! I didn’t see any visible dirt, so maybe key flakiness is due to manufacturing residue. [I’m not a smoker.] Based on Web comments, flaky Keystep keys is a common problem — a frequent problem in what is otherwise a fine product.

From here, you need to reverse the disassembly steps in order to nail everything back together again.

Fixing broken keys or aftertouch

Now, to explain the missing keys. The original video demonstrates a repair to the aftertouch strip. I naively thought that I could get access to the key contacts through the top of the keybed. You only need to remove keys when fixing the aftertouch strip or broken keys. Do not remove keys if your goal is only contact cleaning.

Keystep key spring detail

My mistake did create a photo-op, however. In the picture above, you see the springs which give the keys their bounce. The springs hold the keys in place. To remove a key, you need to gently push down on the spring and release the “rounded” end of the spring from the black keybed frame. These little buggers will fly off, so be careful! During re-assembly, the conical ends fit into the key holes. Stretch the spring until the rounded end fits into the corresponding pocket in the keybed frame. Another re-assembly tip: do all of the black keys first.

Keystep with keys removed

The final picture shows the top of each rubber contact pair poking up through the black keybed frame. These are the top sides of the rubber contacts that we cleaned. The black strip running along side the key contacts is the aftertouch strip.

I connected the reassembled Keystep to my PC (via USB) and got the familiar start-up light show. I launched MIDI OX and tested each key. All keys responded quickly and reliably.

All in all, the process was relatively easy although care must be taken. I like the Arturia Keystep and love it even more, now that all of the keys are working.

Bonus: Learn how to tune littleBits with Keystep.

Copyright © 2020 Paul J. Drongowski

littleBits envelope generator

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In my last post, I investigated the gated CV signal produced by the littleBits MIDI Module. Now, let’s take a look at the Envelope Module.

littleBits Envelope Module

The littleBits Envelope Module is rather basic with only attack and release controls (no decay or sustain controls). The module has two inputs:

  • The primary input at the left end of the module typically receives the audio to be shaped by the envelope.
  • The trigger input receives an (alternative) trigger signal.

The Envelope Module triggers in one of two ways:

  • When the primary input transitions from zero to a positive voltage.
  • When the trigger input transitions from zero to a positive voltage, usually 5 Volts.

Allowing the primary input to trigger envelope generation simplifies connection. It is also easier to use conceptually. A beginner doesn’t need to understand envelope generators, voltage controlled amplifiers and how the two interact. A beginner doesn’t need to wire in a separate envelope generator. Everything happens along a single audio signal path and “it just works.”

The simple circuit below is all one needs to get started with synthesis:

    Power --> MIDI --> Oscillator --> Envelope --> Speaker

If you have is the basic Synth Kit, then the MIDI Module may be replaced by the Sequencer Module or Keyboard Module. As we saw in the last post, the Gated CV output from the MIDI Module turns the oscillator ON and OFF (gate) and sets the oscillator pitch (CV). When the Oscillator is generating audio, the audio signal triggers the Envelope Module which shapes the audio amplitude. The shaped audio (now with attack and release segments) is finally sent to the speaker.

I connected this simple circuit to a dual trace oscilloscope. I found that the attack and release phases are sequential without an intervening sustain phase. The duration of the entire envelope is the sum of the attack duration and release duration. There isn’t a decay phase either. In other words, holding the gated CV longer does not sustain a note! The maximum duration of the attack phase is about 1 second and the maximum duration of the release phase is about 2 seconds.

Envelope Module in action (max attack and max release)

The oscilloscope traces above show the final, shaped audio signal when attack and release are set to maximum. [Click images to enlarge.] The top trace (green) is the gated CV signal from the MIDI Module. The bottom trace (red) is the shaped audio signal. Each horizontal grid mark is 0.5 seconds. Please note that the gate must be as wide as the attack duration plus the release duration to obtain the full contour.

littleBits Filter Module

Skipping ahead to the Filter Module for a moment, the Filter has an input which allows cutoff frequency modulation. In a typical modular synth, this input is tied to a separate envelope generator. In keeping with the littleBits “It just works” philosophy, you can drive the cutoff input with the audio signal as seen in the circuit below:

                                                ---- 
                                               |    | 
                                               |    V 
   Power --> MIDI --> Oscillator --> Envelope --> Filter --> Speaker

Yes, this actual works as shown in the oscilloscope traces below. The top trace is the gated CV signal from the MIDI Module. The bottom trace is the output of the Envelope Module which is connected to the Filter cutoff modulation input.

Modulating the filter with envelope shaped audio

littleBits envelope generator

I’ll bet that you’re wondering if the littleBits Envelope Module can be made into a conventional envelope generator. So did I. It would be great to have a conventional synthesis chain with separate envelopes for amplitude and filter with separate attack/release (AR) controls for each envelope.

Here’s one experimental solution:

               --> MIDI IN  --> Oscillator --> Filter --> Speaker 
              |       |                           ^ 
    Power --> |       | Trigger                   | 
              |       V                           | 
               --> Envelope ----------------------

If you have a second Envelope Module, you can insert it between the Filter and Speaker Modules, forming a conventional OSC→VCF→VCA chain. I have only one Envelope Module and built the circuit shown above. I used a littleBits Split Module to send the Power output to the MIDI Module and Envelope Module. This is the ideal situation for powerSnaps, if you got ’em.

littleBits Power Module (old model)

How does this circuit work? The Power Module provides the +5V and ground power rails, of course. The Power signal output is tied to 5V. Thus, the Envelope Module sees a constant 5V signal at its primary input. The littleBits MIDI Module triggers the Envelope module. The envelope generator inside the Envelope Module triggers and shapes the constant +5V input signal into the familiar attack and release envelope contour.

Output from the “pure” envelope generator circuit

The oscilloscope traces above show the gated CV signal (top/green trace) and the output from the Envelope Module (bottom/red trace). Yep, the final audio sounds exactly as expected having the familiar wah-wah filter funk. The final audio sounds cleaner when the filter cut-off frequency is modulated by the “pure” envelope generator.

One final detail. The internal littleBits envelope generator is based on a 555 timer circuit. If you’re curious about the internal design of this or any of the littleBits modules, be sure to visit the littleBits Eagle file repository where you will find schematics.

Copyright © 2020 Paul J. Drongowski

littleBits Control Signals

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I got the itch to experiment with analog audio processing and finally unpacked the old littleBits synth modules. Folks hack the Korg Monotron series, so why not hack littleBits modules instead? The modules are inexpensive when compared with Monotron and are easily reconfigurable while experimenting.

Since I last wrote about littleBits (circa 2017), Sphero purchased the littleBits company in 2019. Fortunately, they retained the littleBits forum.

Not so good, neither Sphero nor littleBits provide precise documentation about synth module functionality or the input and output signal characteristics. Precise information is needed especially when interfacing modules with the outside world including module synth gear. Timing information, in particular, is needed.

We do know a few things about littleBits, however. littleBits modules normalize input and output signals to a 0 to 5 Volt range. Both digital and analog signals are normalized. Normalization facilitates the plug-and-play module architecture and you can freely interchange analog for digital and vice verse.

Background

Before diving in, here is a little background information about the signal types and terminology commonly used in modular synthesis.

“Control voltage (CV)” is an analog signal which controls continuous functions like oscillator pitch generation, envelope and filter modulation, etc. CV sweeps continuously across an operational range, e.g., 0 to 5 Volts.

“Gate” is a digital signal. It is an ON/OFF signal. A keyboard, for example, asserts gate when a key is pressed and drops gate when the key is released. Gate indicates a condition, e.g., a key is pressed. The leading and trailing edge of the gate indicates a change in the condition.

“Trigger” is a digital signal similar to gate. However, trigger is usually a short digital pulse. Trigger is intended to indicate an event, like a clock tick, not just the presence or absence of a condition. Trigger signals often control synchronization.

Of course, electrons are electrons and one is free to combine CV, gate and tigger in any manner. Not all mixtures are meaningful (useful), however.

Details about CV, gate and trigger vary from manufacturer to manufacturer. Moog, for example, use the linear Volts per octave convention. On the other hand, old Yamaha and Korg synths use the Hertz per Volt convention. Maximum and minimum voltages level may differ by manufacturer and so on.

My goal here is understanding the convention used by littleBits.

littleBits MIDI and oscillator modules

I decided to start from the front of the synthesis signal chain and work back. The first stage in the synthesis chain is the littleBits MIDI module. A close look at the MIDI module signals in action should tell us how littleBits implement basic synthesizer control (CV, gate and trigger).

littleBits MIDI module

The MIDI module has a USB-B device port that presents itself to the USB-A host as a class-compliant MIDI device. The MIDI module supports both USB MIDI IN and USB MIDI OUT. However, the module operates in one mode (IN or OUT) at a time. The mode is selected by its mode switch (duh!).

  • IN mode: Receives MIDI messages from the host.
  • OUT mode: Sends MIDI messages to the host.

This blog post focuses on IN mode.

IN mode converts incoming MIDI note messages to two signals:

  • Gated control voltage (gated CV)
  • Trigger

Although littleBits call the digital output “Trigger,” it really is a gate signal, as we shall see.

littleBits Oscillator module

The littleBits Oscillator module is a pretty simple affair. The sole input is the (gated) control voltage which changes the pitch. The sole output is either square or saw wave as selected by the waveform switch.

The test rig

Here’s my test and measurement approach.

The littleBits signal chain consists of a power module connected to the MIDI module which drives a littleBits oscillator module. I split the gated CV signal sending it to both the oscillator and a proto module. The oscillator output is sent to a speaker module, giving me aural feedback. Hey, is this thing on?

MIDI module/Oscillator test circuit

The GND and gated CV signal are sent from the proto module to a Gabotronics Xminilab oscilloscope. I attached another proto module to the MIDI module “trigger out.” The GND and “trigger out” from that proto module are went to the second channel of the oscilloscope. Thus, I can monitor both the gated CV and “trigger out” and see the timing relationships between the signals.

SONAR/Oscilloscope test rig

The Xminilab front panel user interface is a little fiddly. So, I connected the oscilloscope to a PC running the Gabotronix oscilloscope application. This arrangement makes it sooooo much easier to configure the oscilloscope and to capture screen shots.

The USB MIDI comes from the PC, too. SONAR generates MIDI messages and sends them to the littleBits MIDI module. Test messages are produced from a repeating one measure loop (80 BPM or so). The repeating loop gives me good repeatability.

The signals under test

As noted by other experimenters, littleBits combine gate with CV functionality. When the MIDI module receives a note ON message, it:

  • Asserts the trigger signal, and
  • Drives the gated CV output with a positive voltage proportional to the MIDI note number.

The MIDI note range is C2 to C6 (4 octaves). MIDI note C2 generates a gate CV voltage of 0.2 Volts. From there, the output voltage increases by 1 Volt per octave (1V/oct). Each semi-tone step increases the voltage by 1/12 Volts. The module asserts trigger by raising its output voltage to 5V.

When the MIDI module receives the corresponding note OFF message, it:

  • Drops the trigger signal to 0V, and
  • Drops the gated CV output to 0V.

Notice that the gated CV output is asserted and dropped in parallel with the trigger output. Trigger is always driven to 5V while the gated CV voltage is positive and is proportional to the MIDI note number.

The screenshot below illustrates the operation of these two signals. The top trace (green) is the gate CV voltage. The bottom trace (red) is the trigger voltage. [Click images to enlarge.]

Gated CV (green/top trace) and “trigger” (red/bottom trace)

The MIDI test loop plays C2, C3, C4 and C5 in succession and repeats. The stair steps in the top trace show the effect of each successive note in the loop. The vertical display scale is 2.56V per grid division. You can see that each successive step is 1 Volt higher starting with C2 at 0.2V.

The trigger and gated CV traces are in temporal lock-stop, i.e., they rise and fall together. The width of the trigger signal is always the same width as the gated CV signal. Please recall that “trigger” in synth-speak is normally a fixed-width narrow pulse. That’s why I think the littleBits “trigger” signal is really a gate signal.

So, why do littleBits use a gated CV? Short answer: In conventional use cases, both gate and CV can be sent through a single wire (connection). The synthesist doesn’t have to route two separate wires (connections). The simplified wiring makes life easier for novice users (kids). The synthesist merely lines up a keyboard (sequencer, MIDI module) with an oscillator module and “it just works.” We will see other instances of the “It just works” philosophy in the envelope module, too.

C2, C3, etc. are MIDI note numbers and nice names. However, you’ll need to tune the Oscillator module to obtain the correct musical pitch.

Copyright © 2020 Paul J. Drongowski

Best things in life are free

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Yep, still here and no trouble staying busy! We’ve been hit by a tsunami of free on-line content and software sales. The good news — it’s free (or at a discount). The bad news — the amount of time required to download, install, activate and maybe, gasp, actually use some of these samples, plug-ins, etc.

The list of free stuff is astounding. The Loopmasters, Loopcloud, Plug-ins Boutique and Producer Tech conglomerate has been veru generous during the pandemic and the summer season. The first stay-in and create promotion distributed:

That’s a bunch of good stuff, especially Neutron Elements. I haven’t dipped into Producer Tech, as yet, but the Ableton Live tutorials are inviting.

I just cashed in the summer stay inspired promotion:

These plug-ins are really worth it and useful. I Heart NY does parallel compression, good for mastering among other uses. Vocal Splitter separates mono vocals into stereo (ye olde split, delay and detune trick). Smasher is an Urei 1176 compressor emulation dedicated to the British all-buttons-in sound. Sure, the plugs are somewhat single purpose, but they sound great and are simple to use. Frankly, with all of this free content (!), I don’t have time to dial things in. 🙂

Other notable free plug-ins are:

Sweetwater ran a promotion with iZotope, giving away the Ozone Elements mastering suite. Between Ozone Elements and Neutron Elements, that’s half of the iZotope Elements suite for nada.

I need to mention my favorite score from the Christmas holiday season: Arturia’s EMT-140 Plate Reverb. I have a fondness for plate and Arturia put together a beautiful EMT-140 emulation.

If that’s not enough, shake in the Korg software sale including Korg Module Pro and discount Cubase updates from Steinberg.

Plugin Boutique had a sale on zplane deCoda. deCoda is like Yamaha’s Chord Tracker on steroids, building on zplane’s experience in spectral analysis. Sure, it’ll identify the measure, sections and chords. However, you can draw MIDI notes on top of a spectral plot and export the MIDI to a file. A great way to capture a melody line from a song. deCoda has a focus panel which restricts analysis and playback to a specific frequency band and area within the stereo field. I see many uses beyond chord extraction!

Check out this introductory deCoda video. zplane have a v1.1 update in beta testing now. The beta adds the ability to save the chord progression to a file — a must-have feature. In v1.0, you need to jot the chords down by hand.

Hey, hey. If you keep your eyes and ears open, you can save some serious cash. The plugs and stuff mentioned here are first-rate, not sleazy hacks. Nows all we need is a time machine to learn, experiment, and put everything to good use.

Copyright © 2020 Paul J. Drongowski

Mini review: Korg Module

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Korg have extended their summer apps and software sale. Sale is on starting today (June 24) and ending Wednesday, July 15, 2020.

They finally got me with Korg Module Pro. The backstory…

I installed the free version of Module when I assembled the Korg NTS-1, hoping that it would unlock a few extra instruments in Module. For some reason, nothing unlocked and I gave up. I really wanted to assess the five built-in engines before springing for Module Pro.

Well, shucks, sight to the blind. Last week, I cast my gaze across the studio, coming to rest on the MicroKorg XL. Duh! Why didn’t I reach for the MicroKorg to begin with? After wiring up, the MicroKorg unlocked the electric piano, organ, clav, and string engines. Only one patch each, but certainly enough to get a good taste.

Needless to say, the five engines are pretty darned good. I sprang for Korg Module Pro and the Module Performance Expansion pack. The Module Performance Expansion pack adds more voices, MIDI CC learn and the ability to split and layer.

The ability to layer is very handy as I always find Korg’s acoustic instruments to be a little bit raw on their own. Sure, effects help to dress up the voices, but a soft pad adds warmth to strings and so forth. Orchestration 101.

MIDI CC learn is a bit of a necessity, I discovered. Unexpanded Module Pro responds to specific MIDI CC messages. For example, CC#100 controls organ rotary speaker speed, a rather essential element. To my chagrin, I discovered that the Yamaha MODX, which I am using as a controller, does not send CC message higher than CC#95! What the what? MIDI learn allows you to assign a controller to rotary speaker speed or other Module parameter of interest. [Check the update below for the correct solution!]

I connected the Yamaha MODX to the iPad via Apple Camera Connection Kit and an ancient IK Multimedia iRig 5-pin MIDI interface. Why 5-pin? That’s the other gotcha. I initially connected the MODX to the iPad via USB. Module receive the MIDI OK, but somehow the outgoing audio stream was lost with no signal at the 3.5mm headphone output. [See the update!]

I may look for a different audio/MIDI interface solution as I hate using the 3.5mm headphone jack. It’s not mechanically robust and it’s all too easy to get ear-itating scratchy audio. I don’t want to spend a lot of money and don’t want any solution involving powered hubs and such. I might give the Alesis Control Hub a try or maybe Korg’s own plugKEY. The Control Hub is a legacy product and availability is spotty. The plugKEY is a little more expansive, but is purpose-built for iPad software instruments and is Lightning-only. The Control Hub is USB-B class-compliant.

My only remaining nit is also one of my pet peeves. Software vendors should be forthcoming and specific about voices (patches) available at verious tiers. In the case of Kork Module, the free version has only one unlocked engine — acoustic piano and one patch:

    Acoustic Piano       Natural Grand

When the free version is connected to a Korg synth like the MicroKorg, you get five unlocked engines, one patch per engine:

    Acoustic Piano       Natural Grand
    Electric Piano       Natural Tine EP
    Organ                Simple Organ
    Clav                 Clav CA
    Strings/Choir        Strings

The engine beneath Strings/Choir is really a sample-playback engine and it’s not limited to strings!

Korg Module Pro unlocks many additional patches for the five engines:

    Acoustic Piano
         Natural Grand      Bright Grand
         Dark Grand         Heavy Touch Grand
         Light Touch Grand  Damper Reverb Grand
         Cinema Piano       Mono Attack
         Comp Piano         Upright Piano
         Radio Piano        Honky Tonk
         Flange Piano       Electric Grand
         Chorus E.Grand     AOR E.Grand
         Ac+El Piano        Pad Piano
         Spacy Piano        Strings Piano 1
         Strings Piano 2    Choir Piano
         Twinkle Piano      Stack Piano
     Electric Piano
         Natural Tine EP    Hard Tine EP
         Soft Tine EP       Tremolo EP
         Phaser EP          Chorus EP 
         Boomy Vibe EP      Auto Wah EP
         Deep Mod EP        Distortion EP
         Hybrid EP          Dark Sine EP
         Digital EP         Synthetic EP
         Pad Tine EP        Strings Tine EP
     Organ
         Simple Organ       Dark Organ
         Soul Organ         Jazz Organ
         Memphis Organ      Gospel Organ
         Clean Organ        Bright Organ
         Drive Organ 1      Drive Organ 2
         Full Organ 1       Full Organ 2
         Perc Organ 1       Perc Organ 2
         Perc Organ 3       Perc Organ 4
         Vox Organ 1        Vox Organ 2
     Clav
         Clav CA            Clav CB
         Clav DA            Clav DB
         Wah Clav           Phaser Clav
         Distortion Clav    Mute Clav
         Psychedelic Clav   Clav Guitar
     Sample-playback
         Strings            Slow Strings
         Strings Pad        Analog Strings
         Phase Strings      Flange Pad
         Choir Pad          Vocoder Pad
         Brass Ens          Octave Brass
         Funky Sfz Brass    Hybrid Brass
         Analog Brass       Soft Horn
         Warm Pad           Saw Pad
         Ambient Pad        Bell Pad
         Saw Wave           Chiptune Wave
         Synth Stab         Unison Synth
         Saw Synth          Soft Synth
         Rez Comp           Rez Square
         Synth Clav         Saw Pluck
         Square Pop         Detune Sine
         Digital Bell       Ring Bell

The electric piano is quite nice; the patches provide a wide range of Rhodes tone. The rotary organ patches cover a useful range, too, including a pair of VOX combo organ sounds. The clav is up-to-snuff and the patches cover the usual favorites. The sample-playback sounds are strong on ensemble voices, not so much lead tones or solo instruments.

The Module Performance Expansion pack rounds out the sample-playback sound set with guitars, bass, solo instruments, etc.

    Sample-playback
         Violin             Cello
         Pizzicato          Chamber Strings
         Strings Ensemble   Tremolo Strings
         Romantique Strings Synth Strings
         A Capella Pad      Bubble Choir
         Solo Trumpet       Band Brass
         Fanfare            Horn Ensemble
         Synth Horn         Solo Flute
         Vibrato Flute      Pan Flute
         Alto Saxophone     Tenor Saxophone
         Wind Ensemble      Chamber Orchestra
         Unison Stab        Mono Dark Lead
         Mono Synth Lead    Detune Saw Lead
         Octave Lead        Talking Lead
         Analog Piano       Synth Pad Piano
         Velocity Synth     Synth Pad
         Dark Pad           Snow Pad
         Aurora Pad         Artificial Effect
         Filter Motion      Air Organ
         Vibra-phone        Glockenspiel
         Celesta            Steel Drum
         Tubular Bell       Mysterious Bell
         Vibrato Glass Bell Bell Tower Pad
         Foggy Hills
         Ac. Guitar         Nylon Guitar
         Electric Guitar    Guitar Dist.
         Harp               Sitar
         Ac. Bass           Walking Jazz Bass
         Fretless Bass      Finger Bass
         Mute Pick Bass     Slap Bass
         Fat Pulse Bass     Filter Bass

All of these sounds can be used as layer elements, too. That’s a lot of detail, but it should give you a better sense of the product feature tiers.

Update

After spending more time with Korg Module Pro, I’m happy. The sounds are first rate without much filler or junk. Some of the sounds are inspiring.

Further experiments…

I connected the Yamaha SHS-500 keytar to Korg Module Pro over Bluetooth MIDI. Pairing was a breeze, I couldn’t discern any annoying latency at all. There are a few patches where I dialed up the effect level — par for the course. I can see the SHS-500 plus iPad/Module as a lightweight portable rig. Going wireless would be a real boon for the crazy small spaces that I play in.

I also gave MODX another shot as MIDI controller. Success! The digital audio stream is sent back to MODX on its USB class-compliant audio device. My initial mistake was a head-slapper. Pay attention to the MIDI and audio meters in Module’s upper left corner. At first, I saw MIDI activity and no outgoing audio level. Should have been a big clue. Check and set Module’s OUTPUT LEVEL knob and make sure it’s turned up. Doh!

I resolved the organ rotary speaker speed issue by reading the manual and noting the organ/damper pedal setting. Module receives CC#64 sustain. When the organ/damper pedal setting is “Rotary,” sustain toggles the rotary speaker speed — no MIDI CC learn is necessary.

That’s it! Korg Module Pro 50% off is money well spent.

Copyright © 2020 Paul J. Drongowski

What did you do in self-isolation?

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Yes, this site still does music! 🙂

Several weeks ago, I decided to record the church tunes that I enjoy playing. It’s best to start with favorites, as most of you know how you come to detest a track after playing it over, and over, and over again during production. Energy quickly dissipates when micro-editing MIDI events or digital audio…

Before getting into production notes, here are links to the final tracks (all MP3). The goal was to crank out a new tune each week and send it to the folks in our music ministry. Some tunes are a little more polished than others. Please consider them “demo quality.”

Without going too far into the technical weeds, the primary sound source is Yamaha Genos™ and the primary vocalist is my spouse Fran. With the Mill Creek Chorale on hiatus — aren’t we all? — I was happy that she could contribute and have fun, too.

Production notes

So, how did all of this go down?

These demoes show off the Yamaha Genos as a sound source and production tool. I had two main subgoals:

  1. Learn how to record a demo with Genos in either audio or MIDI format.
  2. Learn how to mix down with Steinberg Cubase Artist and try out a few of the freebie plug-ins that I’ve collected.

By and large, Genos and Cubase were the main production tools although I back-slid into SONAR on a few occasions for MIDI editing. Old habits die hard. Workflow was not strictly linear from Genos to Cubase. In a few cases. MIDI and/or audio (stereo 16-bit 44,100 WAV) were slung back and forth between tools.

Yamaha Genos

Genos is the sound source with one big exception: drawbar organ. When you hear B-3, you’re hearing Yamaha MODX through an Electro-Harmonix Lester K. I wanted to hear Lester K in musical context. It sits in a song pretty well and has more guts than the Yamaha MODX Leslie simulator. By itself, though, Lester K has some high-end swirliness in the upper drawbars, but in a track, it seems to mesh. You be the judge.

Emphasis was on speed. Get the tracks down quickly and finish a song each week ASAP. The Beatles used to call this recording “on heat.” Even so, it’s amazing how modern technology will drag you into the dank chasm of production minutiae. Don’t you just love hearing the same three measures fifty times while tweaking and tweezing. Not.

All vocals were recorded directly to Genos using its microphone input. Full backing and raw vocal tracks were exported to Cubase via WAV. Everything was processed and mixed in Cubase. The final mix was exported from Cubase as WAV, and then trimmed and converted to MP3 using Sound Forge Audio Studio.

Our God Is Here This was the first demo in the series and the process doesn’t get any simpler than this. All was recorded into Genos Audio Multi Recording. Find a beat, turn it on, lay down the organ part. Unfortunately, I didn’t plan for the ending, which is quite ragged. The organ is Genos in this case (not MODX). Kinda plain, huh? The bass is an overdub.

Audio Multi Recording is a nicely done sound-on-sound recorder a la Les Paul, minus tape hiss. There are two stereo tracks: main and sub. You can record directly to either main or sub, and bounce (sub+main) to main. There are options for punch in and overdub. Audio Multi Recording provides WAV import and export, functionality which eventually got a true work-out.

Audio Multi Recording keeps digital audio in a persistent project. A project resides in the internal Genos 60GB user solid-state drive and is always ready. The project remembers audio and mix settings without requiring explicit save and load user operations. That makes for a clean workflow. Export is the way to get digital audio into a WAV file and it mixes the main and sub on the way to WAV. In order to export a solo vocal track from sub, one needs to dial down the main and then wait while Genos writes the WAV file in real time. I wish there was a simple, direct fast export to WAV supporting both main to WAV and sub to WAV.

In The Day Of The Lord I quickly realized that I do need to think ahead and assemble a basic skeleton on which I could build a tune. (Duh!) In this case, Toontrack EZDrummer provided the drum patterns which I pulled together in Cubase. Genos played the MIDI drum track while I recorded the flute as a melodic guide and layered in the bass and organ — all recorded as audio. We then did a few vocal takes to Genos. I transferred all of the Genos audio as WAV into Cubase for the final mix. Vocal processing typically was light: a little pitch correction, EQ, and maybe double tracking. A touch of reverb (Cubase Revelation) blends everything together here.

Stop By, Lord This tune makes use of the Genos rhythm accompaniment consisting of main patterns and one-bar fills. I recorded a basic guide track in MIDI using the “BigBandBallad” style as the drummer. This meant switching the main and fill patterns with my left hand while playing the melody with my right hand. I layered in the piano, bass and horns, discarding the guide melody along the way. I added the B-3 organ (MODX through Lester K) in an audio pass. Everything was recorded and produced on Genos since we didn’t record vocals.

Psalm 95 If Today “If Today” makes full use of the Genos arranger features. I played the basic accompaniment track using the “Sunny Reggae” style. Whoever built that style, it must have been a labor of love and it fits this song quite well. I vocoded my voice. Both the accompaniment and vocal tracks where exported to Cubase for final assembly and mix down. I had a lot of fun adding dub effects and tons of reverb, Long live King Tubby!

Rise Up With Him “Rise Up” was recorded to MIDI, again using the Genos rhythm accompaniment as the drummer. The electric piano went down first followed by the bass. The B-3 organ is MODX through Lester K. Backing and vocal audio were exported to Cubase for final mix down. Overall, a pretty simple demo to pull together.

O Sacred Head I recorded the MIDI for this tune a long time ago — in the early 2000s on a Roland XP-60. The guitar picking was carefully edited and assembled (years ago!) from Twiddly Bits. I imported the XP-60 MIDI into Cakewalk, choosing Genos voices and effects. The Genos result versus the original XP-60 is amazing. Fran encouraged me to leave it as an instrumental.

This Is The Day This psalm is long out-of-print. A few years agao, I transfered a scruffy copy of the piano score into Sibelius. So, to kickstart this tune, I exported MIDI from Sibelius, restructured the sections, and humanized the piano as much as possible. I tried to keep the accompaniment simple adding just bass and horns. Once again, the backing and vocal tracks were mixed in Cubase. This demo is a good example of Arturia’s Plate-140 reverb — a freebie that Arturia gave away during the Christmas holiday. I love it.

Lead Me, Lord Another simple turn-on-the-beat-box, sound-on-sound production. Everything was recorded to Genos with the backing and vocal tracks exported to Cubase. (Another example of Plate-140, BTW.) The vocal harmony was generated by a TC Helicon Play Electric added in real time. Recording and production was dirt simple although it took a while to get the TC Helicon configured.

Alleluia! Love Is Alive This was the penultimate demo in the series. The basic track is a stripped down Genos “6-8PopBallad” style. Yamaha tends to over-orchestrate styles, so I kept drum, bass and guitars, tossing the rest. Instead of playing the basic track, I created the accompaniment using chord step-record. This MIDI Multi Recording feature lets a musician enter chords and sections from a lead sheet, quickly creating the song skeleton. You can even try different styles if you haven’t chosen one already. Once the skeleton is set, you expand the chord track into MIDI events, thereby obtaining the full backing track in a Standard MIDI File (SMF).

I added the Celtic violin by playing it into a free MIDI track. Using Sonar, I tweaked the tempo in the full MIDI song in order to add energy as the song progressively builds to the end. Finally, with the MIDI finished, I froze the backing tracking to WAV audio. The backing and vocal tracks were mixed down in Cubase with a little automation here and there to add vocal depth and double tracking.

Conclusions?

The preceding discussion is already a lot to absorb and to process. I’ll take a step back in a future post and try to summarize. All the best to ya.

Copyright © 2020 Paul J. Drongowski

Back In The Day

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A Keyboard Corner member asked what people did for keyboard amplification before PA. Man, that question really kicked off some memories.

Back in the day (1966), I played a Farfisa Mini Compact Deluxe through an Ampeg SB-12 bass amp. It was all I could afford. Mom and Dad lent me the money and I mopped floors at the local donut shop to pay them back. The shop had a wooden floor that was impregnated with grease. I still can’t face donuts to this day. 🙂

Farfisa Mini Compact Deluxe

While packing for the house move, I found an original Farfisa brochure from the 60s era.

The Portaflex was pretty cool with its flip top. The amp was mounted to a covered board which acted as a base for the head and, when flipped over, it became the cabinet cover. The clamps held the base/cover board in place and did double-duty as the speaker connections to the cabinet.

Ampeg SB-12 bass amplifier

The SB-12 had a 12″ Jensen speaker powered by a 25 Watt tube amp. It weighed 47 pounds — the first of a long line of heavy schleps.

Being the 1960s, of course, that wasn’t enough. Since I started playing with electronics and DIY at an early age, I tried my hand at an extension cabinet. I somehow came into a 15″ JBL speaker with a small tear in the cone. Impedance be damned, I just hooked it up in parallel with the Jensen via the clamps. Before building a cabinet, I would carry the JBL around in a suitcase which doubled as a “cabinet.” (!) The tear in the cone lent more bad-itude. [Why fizzy digital distortion doesn’t cut the mustard.]

In the R&B band, the guitars and vocals went through matching Ampeg guitar amps (probably Gemini’s). Only the top local bands could really afford PA for vocals (typically Fenders). Nobody put instruments through PA. The bass player had a Guild ThunderBass amp with that funky head. The bass player was quite good and laid down decent grooves. Can’t remember too much about the psychedelic band…

My failed experiments at extension and PA speaker cabs wound up as end-of-gig props. When we saw The Who trash their gear, we thought “What the heck!” I’d pull one of the legs off of the Farf and ram it through one of the prop cabinets.

My dream rig would have been a Vox Continental through a Fender Twin Reverb or Fender Super Reverb. I copped the Fender tilt-back idea and built a tilt-back stand for the SB-12. That got the speaker pointing up toward my ears.

Both the Connie and the Fenders were out of my financial reach. It took me three years to pay back my folks. By then, I had to sell the whole rig in order to make the college tuition nut. Given the rigors of college math, physics and computer science, it was the end of playing for quite a while. I can’t believe how much a vintage SB-12 fetches on the market these days!

The Farfisa Mini Compact Deluxe left me with no delusions about 1960s electronics. I tried tuning the F# oscillator and bunged the tuning coil. That was an unnecessary repair expense. That’s why I’m happy as a clam to play the Yamaha Reface YC today. The YC does a good job nailing the Farfisa and Vox.

A few other memories stick out like playing music fairs on stage/demo gear with the psychedelic band. One stage was incredibly small and I had a horn driver literally right in my ear. We played Doors, Steppenwolf, Vanilla Fudge, etc. at phenomenally loud volume, attracting every biker within earshot. They loved us. I think I still suffer hearing loss from those jobs.

Before signing off, I want to plug “Classic Keys: Keyboard Sounds That Launched Rock Music” by Alan Lenhoff and David Robertson. I received a copy yesterday and gave it a quick browse. The photography is excellent and the example gear is in tip-top shape. The book is long on history — less on playing technique and artistis, so some may be disappointed. Discount and used copies are coming onto the market and you may be able to save a few bucks if you can’t pony up the full $60USD. Recommended.

Copyright © 2020 Paul J. Drongowski

Sonogenic voice editor

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The Yamaha SHS-500 Sonogenic is a good sounding syntheizer which lets you jam along with ChordTracker songs. The SHS-500 includes a General MIDI Level 1 multi-timbral tone generator that is accessible over MIDI (Bluetooth, 5-pin or USB). Yamaha doesn’t promote the General MIDI capability, but it’s there!

Update: I added a post showing how to customize the Sonogenic voice editor user interface.

The Sonogenic lacks three critical features that one finds in a typical desktop synth:

  1. Although the Sonogenic has 28 great voices and two drum kits built-in, it lacks many important instruments like organ, double reeds, tuned percussion and soft synth pads.
  2. Internal voices cannot be edited, e.g., attack, filter cutoff and so forth cannot be adjusted.
  3. The chorus and reverb types are preselected and cannot be changed.
  4. Edits and changes cannot be stored into and recalled from user memory slots.

This is the ideal situation for a tablet-based app.

MIDI Designer is an iPad-based tool which supports creation and use of MIDI voice editors and controllers called “layouts.” Users have built and shared layouts for many popular synths. Now, I’m pleased to add the SHS-500 Sonogenic layout. With this layout, you can play the General MIDI (GM) voices, change reverb and chorus types, edit General MIDI (GM) voices and save all of your work in MIDI Designer presets. If you turn Sonogenic LOCAL sound generation on, you can layer an internal voice with a GM voice.

This post describes the Sonogenic layout. I recommend reading my post about MIDI Designer to Sonogenic communications (MIDI flow) first. It will help you to understand the relationship between the SHS-500 and the MIDI Designer Sonogenic layout. The write-up may even inspire a new way of using MIDI Designer with Sonogenic.

One thing that’s nice about MIDI Designer and layouts — you can customize them. So, if you want to modify my layout, don’t hesitate. First, though, you should read my post describing Sonogenic’s MIDI implementation. Then you will know more about the MIDI messages behind the layout’s controls.

Click this link to download my Sonogenic layout for MIDI Designer. Use iTunes file sharing to install the layout in MIDI Designer. I plan to upload the Sonogenic layout to the MIDI Designer web site.

Connection

Although you could connect by USB or 5-pin MIDI, the Sonogenic, MIDI Designer and Bluetooth MIDI are made for each other.

midimittr Bluetooth connection to Sonogenic

First, launch the free midimittr app which acts as a bridge between Sonogenic, Bluetooth MIDI and MIDI Designer. midimitter lets MIDI Designer echo Sonogenic’s MIDI note on/off, modulation and pitch bend messages back to the Sonogenic. You should turn Sonogenic LOCAL off unless you intend to layer a Sonogenic voice with a GM voice.

MIDI Designer connection

Next, launch MIDI Designer and make connections to midimittr as shown in the screenshot above. Then load the Sonogenic layout into MIDI Designer. You should be ready to go at this point.

Voices and effects

The Sonogenic layout is separated into three tabs: Effects, Voice and Voice Edit. (See the screenshot below.) Effect-related controls are on the left-hand side of the screen and voice-related controls (tabbed pages) are on the right-hand side.

Effect and voice selection

Selecting a GM voice

The Sonogenic has a strict division between its keyboard sound and the General MIDI sounds over MIDI. You can think of the keyboard sound and GM sounds as two distinct tone generators, each with their own controls. The keyboard sound is selected and controlled through the Sonogenic front panel. The GM sound(s) is selected and controlled by the MIDI Designer layout.

The Voice page has an array of voice buttons. The 28 buttons at the top of the page select one of the preset “panel” voices. The two large buttons in the middle select one of the two preset panel drum kits. The buttons at the bottom of the page select a voice from the General MIDI sound set.

Please note: if you select a panel voice on the Voice page, you are changing the current General MIDI sound. The Sonogenic keyboard sound remains the same. The separation may seem artifical, but it lets us layer two sounds: the keyboard sound and a General MIDI sound.

The Sonogenic panel voices are generally better-sounding than the equivalent GM voice. The layout provides direct access to the panel voices while providing 12 buttons which can be customized for your own favorite GM voices. Of course, you’ll need to learn how to edit the GM buttons…

Effects

The large buttons on the Effects page choose the current reverb and chorus type. Like the voice buttons, the reverb and chorus effect type buttons are “radio buttons,” i.e., you can select only one effect type at a time within the reverb group or chorus group.

The reverb (Rev) and chorus (Cho) sliders adjust the reverb and chorus level for the General MIDI sound. [By the way, the GM voice and its effect levels are on MIDI channel 1.] Change the amount of reverb or chorus effect here. The sliders do not affect the keyboard sound — only the GM sound.

Changing the chorus and reverb type also affects the keyboard sound because the chorus and reverb units are shared by the keyboard sound and the GM tone generator. Reverb and chorus level only affect the GM sound [MIDI channel 1].

The four small buttons are utility buttons:

  1. XG On: Sends an XG System reset to the GM tone generator. This resets the voice (acoustic piano) and all internal MIDI controller values.
  2. Local: Turns Sonogenic LOCAL CONTROL on and off.
  3. All Off: Turns off all notes which may be sounding — a panic button.
  4. C3: Plays the MIDI note C3. Good for testing edits and changes.

Use the XG On button sparingly. The GM tone generator and layout do not automatically re-synchronize with each other.

Voice editing

The Voice Edit page is where you adjust basic voice characteristics like volume (Vol), attack time (Atk), release time (Rel), filter frequency (Freq) and filter resonance (Res). You can spruce things up with these controls. The attack, release, frequency and resonance controls behave like “quick edit” controls, that is, they are offsets from the preset voice parameter values. The middle position (64) specifies a zero offset leaving the original value unchanged. Higher values add an offset and lower values subtract an offset. So, if you want to increase attack time, move the attack slider up. If you want to shorten attack time, move the attack slider down.

Effects and Voice Edit pages

Portamento adds a glide between notes. Press “Porta On” to turn portamento on and press “Porta Off” to turn portamento off. The portamento time slider (Porta Time) sets the glide time.

The velocity sensitivity knobs change how the voice responds to MIDI note velocity (touch). The two voice parameters are:

  1. Velocity Sense Depth (VelDepth)
  2. Velocity Sense Offset (VelOffset)

Please see Yamaha’s explanation in the figure below.

Velocity Sense Depth and Offset

Organ voices, in particular, should not respond to velocity, i.e., a note is either on or off. To achieve this kind of touch response, set velocity sense depth to zero and set velocity sense offset to a value in the range 110 to 127.

The keyboard voices have a default volume which is louder than the General MIDI voices. You may need to set the volume slider (Vol) above 100 in order to get a better balance (mix) between panel and GM voices.

MIDI Designer presets

MIDI Designer itself implements preset storage and recall. A MIDI Designer preset is a snapshot of all the current values in a layout. Here’s a typical usage scenario:

  1. Select a voice.
  2. Select and adjust chorus and reverb effects.
  3. Tweak the voice (e.g., change filter cutoff, etc.)
  4. Save the finished voice as a MIDI Designer preset.

It’s easy to save a preset. Press the more button, press the “Save” button at the bottom of the drop-down menu, and then press one of the ten preset buttons. To recall a preset, simply press more followed by the desired preset button.

MIDI Designer has two groups of presets: regular and alternative. There are ten preset slots in each group, so you get twenty presets total. The Alt button selects the alternative group.

Potential issue: Portamento sometimes stays on (or off) after selecting a preset that changes portamento state. [I’m still investigating.]

Limitations

I experimented with several other controls of the kind normally found on a desktop synth. Unfortunately, the SHS-500 MIDI implementation is rather limited. Here are some known shortcomings:

  • Transpose and note shift
  • DSP effect control
  • Mono and poly mode selection

Should I make any progress with these deficiencies, I will issue an update.

Copyright © 2020 Paul J. Drongowski