The Sequential Circuits Six-Trak Analog Synthesizer

This video, via AnalogAudio1, takes a look at the vintage Sequential Circuits Six-Trak analog synthesizer:

Synthesizer demo of the analog synthesizer SCI Six-Trak from 1984. It was the first multitimbral MIDI synth on the market (it came before Oberheim Xpander).

In this movie I play some of my own sounds – on some sounds I used a digital delay (Roland DEP-5) and reverb (Lexicon MPX-500). In the intro I used the sequencer of the Six-Trak.

The Six-Trak has 1 VCO per voice (6 voice polyphonic). It also has 3 ADSR, 24 dB VCF, noise generator, LFO with different waveforms. It has a sort of “slimmed down polymodulation”: VCF modulation by VCO for dirty and metallic timbres. Unison mode for fat, monophonic sounds. Great “stack mode” allows layering of six different patches.

I like the Six-Trak very much. I would wish it had multiple outputs and a chorus effect.

The Six-Trak is not on a par with some of Dave Smith’s other classic synths. The Six-Trak has a fairly limited architecture and was designed to be more of an entry-level synth.

Nevertheless, resale prices for the Six-Trak have jumped in the last few years, as interest in analog synths has soared and people discover that the Six-Trak can make some great sounds.

13 thoughts on “The Sequential Circuits Six-Trak Analog Synthesizer

    1. I have my MoPho mounted to my Six-Trak like that, too. Only I took off the feet so it is flat against the panel.

      I like my Six-Trak, it isn’t the most amazing thing in the world but it makes some sounds than none of my other gear can make and ends up in most everything I record these days. Running it through a vintage Small Stone really makes it sound great. It can do really good long slow pads and there is something I really like about the square wave LFO modulating the pitch and/or filter. The latest OS from Wine country will remember the midi settings and it is easy to get in to the thing. One of my voices wasn’t tuning right and I swapped the chip, so easy even I could do it.

      I recommend one if the price is right. Most of us have some sort of controller with knobs and sliders these days and creating a template is super easy.

  1. SCI also hade a computer MIDI interface for the SixTrak that went with the Commodore 64. This software allowed a user to sequence the voices in the synth individually and assign seperate patches. It also synced to a drum machine.

    1. You can sequence the voices individually via midi. Without the c64 software. I have one, its 6 part multitimbral. The commodore midi interface/software was pretty cool, I have several working c64’s, I’ve wanted to get a drumtraks to try out the old school setup for ahwile now, but they are a bit overpriced on eBay IMHO.

  2. I haven’t used mine in awhile because its a bit banged up (a few broken keys, broken pot shaft on the master tune). But it’s a cool synth. The most interesting feature, aside from being multitimbral, was being able to modulate the filter frequency with the oscillator from some neat fm sounds. I also have an akai ax60, which is based on the same Curtis chip. It also has this feature. Th rev 1 doepfer dark energy also used that chip, albeit only 1 as opposed to 6.

  3. Why the hell are these going for $600 and up on eBay when a Alpha Juno is $200 and is in tune and so much better sounding?

  4. Proof that analog doesn’t mean awesome. I used to own one of these. Besides being relatively uninspiring (in my opinion), the Six-Trak didn’t sound very “big”. Put it next to a Juno 6, and the difference is huge.

    That said, the video does a good job at generalizing what the Six Trak is capable of. Just because it isn’t a great synth, that does not mean it isn’t a competent instrument. It serves a purpose, and can def be used to make great music.

    1. All true, and what AnalOG said, too. The Six-Trak is nothing to get excited about and is disappointing at *half* the going ebay rate. What’s interesting though, is what if the analog poly-prayers of the internet were finally answered with a 2014 equivalent of this? Would the Six-Trak magically “sound good” all of the sudden?


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