Sequential Circuits (SCI) MAX, analog synthesizer, similar to Sixtrak or Multitrak synth.
YouTube Uploaded by wado1942 on Sep 11, 2011
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"I'm just demonstrating this highly underrated analogue synth. This is a video I started shooting over a year prior to uploading it but didn't get to complete till now. I made a web page on my site for it: http://gcmstudio.com/max/max.html. Pictures at the beginning are from when I serviced it after just buying it, though some of the pics are new. I'm amazed at the quality of detail in the build for what was an "inexpensive" synth at the time. You see the labeling & a totally valid musical motif written on a part of the keyboard that nobody was meant to see aside from those who assembled it. Any way, it's a great little instrument with six voices, one oscillator + noise per voice, ADSR volume and envelopes, triangle wave, sawtooth, square wave with Pulse-Width Modulation, four-pole filters with feedback, capable of some really strong resonance. It's one of the first MIDI capable synths able to send and receive on any channel and the companion computer software is what really makes this guy shine. It was actually marketed as a computer peripheral for home recording in 1984. No doubt, it was way ahead of its time."
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"This is the not-well-known, but highly underrated Sequential Circuits Inc. (SCI) MAX, also known as the CM620B. This guy first hit the market in 1984 and was one of the first MIDI keyboards to be able to send & receive information on all MIDI channels. It has six voices, single oscillator + optional white noise per channel, capable of triangle, sawtooth and square (pulse) waves with Pulse-Width Modulation (PWM) using the Curtis SENTE CEM3394 synth chips with internal ADSR volume envelope filters. Each voice also has its own ADSR 4-pole voltage controlled filters, capable of extremely high resonance when desired. There's a sequencer that can store two banks of up to 500 notes each. It has 80 factory preset voices such as organs, strings, woodwinds and classic synths, as well as 20 user voices, which reset when power cycled. Although control from the keyboard itself is rather limited, pitch bend and mod functions are available using an external controller such as another keyboard or MIDI sequencer. When hooked to a proper MIDI controller, computer or even it's big brother, the Sixtrak, worlds of new options appear, allowing the user to create entirely new sounds from scratch. Although it's a mono, polyphonic synth, there's two RCA outputs and a stereo headphone output (which I use use to plug into an amp). Check out this video for real examples on some of this synth's capabilities.
http://www.youtube.com/watch?v=rwceEdT3JY4
Software for controlling the MAX using an excellent GUI is available here. http://www.gcmstudio.com/max/synlib6trak.zip
That's a lot more than what was available to me when I first discovered the MAX over 20 years ago.
This is the B-revision of the MAX, which as far as I can tell, simply mutes the output automatically when self-tuning..."
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