Computer music workstation

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The computer music workstation is the core element of GNAR. It's a bunch of raspberry Pi computers and a cross compiler toolchain for building custom arm packages on Debian. The physical box is located under the Plan 9 workstation and the two share a monitor, but have separate mice and keyboards.

Audio

There was a Denon home theater receiver on the hackshelves. I appropriated it for the power amps and myriad supported inputs. The main outputs of the MOTU 828 are wired to the STEREO CDR [Analog] source input of the Denon. There are some AudioChoice speakers that were on the floor by the west wing lounge. I made some custom cables and hooked them up to the A speaker output on the Denon.

There is a mixer called a Behringer Eurorack MX1604A. It is wired up to act like a 12 channel 4 bus analog mixer with two aux sends. The PC is sort of like the "mixdown" unit but we're not building a recording studio here! So who cares? Wiring diagram forthcoming.

Sometimes there is a Nord Micro Modular connected to the mixer. It accepts audio input as signal to presets 90-99. Many of these are vocoders and amplitude modulation or envelope follower. The input it attached to the mixer aux send 1. Any channel can send signal to the Nord, including the Nord, so WATCH OUT! Feedback warning. This is an excellent analog modeling synth, though the module editing interface is shit.

There's a turntable without a needle. It has a USB sound interface.

There is a cassette player for that vintage feel.

The computer depends on JACK for all sound routing and low latency operation. With our current hardware it's possible to get 96000 Hz @ 24bit 8 channel analog I/O with around 5 ms latency. More on the software stack when it's stabilized.

Software

Much of this software can be used to create digital models of classic synthesizers. The information in the modular synthesizer workshop applies to much of what can be built here using software.

MIDI

There's an Akai APC40 on the table. It is known as a controller for the popular Ableton Live software, though it can also operate in "general purpose mode" by default. This means there is also a MIDI controller with 8 addressable faders, a crossfader, 16 CC1 knobs and a big matrix of buttons that produce note on/off messages.

There is a little 2.5 octave MIDI keyboard. It works.

There is a Yamaha PSR-1700 MIDI synthesizer on the ground. It's big and old. It has some cool sounds but weighs way too much. It uses the old 5 pin DIN MIDI plug. Sound output works via the headphone jack or built in speakers. MIDI in/out work. It's possible to control Sunvox from the keyboard by opening the application on the PC and clicking the mouse on a generator in Sunvox. It's also possible to send MIDI to the keyboard and play lol karaoke files.