Stacking synthesizers (like tiny modules)

5 min readOct 11, 2018

“The interface is basically specified as one-to-one between two units: ie, a synthesizer and a sequencer. Under certain circumstances, however, more units may be placed on a single line.” — Dave Smith & Chet Wood (MIDI proposal, AES 1981)

While navigating the ever-evolving landscape of musical interfaces and how we connect with our instrumentation: dependence on increasingly complex tools and plugins can sometimes abstract away the basic patterns that made a well-aged protocol like MIDI so brilliant at its inception.

Sometimes discovering where MIDI fundamentally began (and getting up-and-running as a user) is more easily done if you have the privilege of working with instrumentation from the era of its birth–but not everyone has that chance (or wants to).

In light of this, the following presents a performance technique that I hope continues to be easily experienced and adopted by curious musicians everywhere–no matter what instrumentation they’re currently working with, or new (more intelligent) architectures emerge: MIDI-stacking synthesizers.

What is MIDI Stacking?

The concept is quite simple:

Build complimentary patches on 2:many discrete sound generating machines in order to link them via MIDI and produce a massive composite sound. In effect, utilizing your available hardware as a ‘synthesizer orchestra’.

Simple stack, huge character. (Korg DSS-1 + Ensoniq ESQ-1)

Identifying your orchestra

Understanding each of your synthesizers and what they can (and can’t) do can be a subtle combination of:

Having a general understanding of the theory behind a given synthesizer (example: FM, Subtractive, Additive, Wavetable).
Giving a synth’s manual a look-over for interesting implementation details.
Hours (at least a few) of kinesthetically creating and modifying patches to become familiar with where each instrument is constrained and shines the most.

If you’ve spent enough time with a device, you’ll likely be able to mentally abstract where you’d like it to sit in the overall composition. For instance, you may be lucky enough to own a Moog one–and you know that a rich, underlying analog patch you produce from that could be complemented by a shimmering, dynamic patch from a Roland D-50 (that has a beautifully different timbre due to it’s digital nature) and a ‘supportive’ sweeping patch from a Yamaha DX7.

Of course, this thought stream only accounts for the ‘synthesizer section’ of your orchestra. If you’re going to integrate with other instruments, knowing their bright spots and shortcomings will be necessary as well in order to compose cohesively.

Setting up your hardware

There’s a few ways you can do this, I’ll cover 2 common setups: the traditional MIDI chain, and integrating a MIDI-Patchbay for a more advanced instrument network.

The ‘traditional’ MIDI Chain

This was the way synthesizer hardware manufacturers originally approached their MIDI implementations in order to play nicely with all other MIDI-enabled instruments. The originating (controller synth) is recognized as ‘Channel 1’, and then every proceeding ‘thru-in’ connection is identified as the next discrete channel. Granted this feels a little abstract now, since we’re used to much more user-friendly interfaces with nice labeling–and the only window into an instrument like the DX7 is a 1 x 3" LCD screen. Still, you can trust these early MIDI-enabled synthesizers are talking with each other beautifully.

In the setup above, the channels become defined this way:

Channel 1: Yamaha DX7 (1)
Channel 2: Yamaha DX7 (2)
Channel 3: Yamaha TX81Z
Channel 4: Casio CZ-1
Channel 5: Roland D-50

Now in order to accomplish MIDI-stacking, you’ll want to set each individual instrument (via their own interfaces) to listen to (MIDI coming from) Channel 1. This way–they’ll all trigger at the same time whenever you depress a key from the controller, and attempt to do something with any other information they receive–for example: filter or envelope parameter changes.

‘Huge FM’: MIDI-Stacking 2 Yamaha DX7s and a TX81Z

A Full Mesh MIDI Network

The example above is simplified, but you probably get the idea: The output of the controller is connected to the input of a patchbay, and the patchbay connects to each instrument directly through an array of MIDI output channels. Typically–MIDI patchbays are able to handle 8-in/8-out, etc, so you have the power to control up to 8 devices with 8 possible input sources. This is ideal for a scenario where you want to control, say, 4 instruments with a keyboard on one channel, and let piano-rolled (recorded) MIDI output trigger some other devices via Ableton Live on the second channel (and you’d still have 6 other input channels left)!

Using a MIDI Patchbay to control MIDI-Stacked Synthesizers with a keyboard and Ableton Live

Enlightenment from a constrained budget

My personal experience with this came from years of operating on a constrained budget. The most valuable synthesizer I own is an original ARP Odyssey–which I saved all summer for in high-school and bought on Ebay when I was 16 for $600. Beyond that, I have purchased ‘decent’ synthesizers via Criagslist for years: used them, sold them, and traded/bought upwards towards better instruments. My personal hardware-bent is towards super expressive & dynamic early-digital synthesizers–which are still currently relatively cheap out there. They’ve (mostly 😉) served me well. 🎹🎹🎹

Don’t let market prices stop you

Craigslist and Ebay are your best friends. You can (still) get a hold of amazing poly-synths for around $200–$300 if you keep an eye out every day and have an idea of what you’re looking for.

The Gear

‘Your mileage may vary’ here, but I will identify some hardware I’ve found either wonderful or extremely useful for performing live (for audiences and recording) over the years. Beyond the analog-stuff, most of these are still cheap!

Synthesizers:

MIDI Devices:

M-Audio MIDISPORT 2x2: Computer/MIDI Interface
360 systems Midi PATCHER 4 x 8: there is also an 8 x 8, but the magic of the 4 x 8 lies in its button interface–which allows you to switch between input sources on-the-fly during a live performance when you’re in edit-mode.

It just takes time–but it’s worth it!

Some final thoughts for getting started:

Depending on your desired setup or what you intend to create: more or less equipment may be necessary to get to the place you want to be.
Time your setup and teardown at the venue! Make a game out of seeing how quickly you can get it done!
The art of this is truly in developing your ‘orchestra’. It’s easy to get excited about ‘what’s possible’ with gear and amass it, but much harder to utilize what you own in a cohesive manner–such that you create an amazing experience for people to enjoy. That simply takes time and dedication to get there.
If I did it — you can too! 🙌