Sequential Circuits Pro One

Sequential Pro One Image

The Sequential Pro One is a wicked little monosynth! It comes from the same period and genre as the Roland SH-101 and Moog Prodigy. The Pro One was basically Sequential's attempt at taking their legendary Prophet 5 poly-synth and packing it into a compact, inexpensive, monophonic analog synth! It has two VCOs, a great 4-pole lowpass filter, two ADSR envelopes (one for filter), and a compact three-octave keyboard. With a Pro-One, you can easily create punchy analog bass-lines and leads or quirky analog synth effects.

The Pro One is an extremely flexible synth with lots of modulation possibilities (ie: the filter, VCO B and LFO can modulate VCO A or B frequencies or pulse widths, or the VCF). There's also an onboard sequencer, something common on many Sequential synths but not often found on other monosynths of the time. It is very basic, however, storing only two patterns and up to 40 notes max. Also, only pitch info is recorded (and in step time only); you can not assign a note duration to any notes. So it's basically a short melodic sketch-pad...but useful. Also onboard is an arpeggiator which has UP and UP/DOWN patterns.

Sequential Pro One Image

The Pro One is relatively simple and intuitive to use, fun, educational and responsible for some of the coolest and hardest basslines in electronic music today! It is used by Hardfloor, Überzone, the Prodigy, Cirrus, Fluke, Depeche Mode, Download, Banco De Gaia, Vince Clarke, New Order, Freddy Fresh, Mouse on Mars, Prince, Soft Cell, Richard Barbieri and Sigue Sigue Sputnik.

But since you can't always find one (about 10,000 were produced), or one that works properly... Wine Country Sequential has come up with a solution! WCS has been servicing old Sequential gear for years, as well as selling repair parts, etc. They have developed the Pro One Software Synthesizer Plug-In, an awesome replica of the original Pro One, both in look and sound! It has some added features and is an incredible way to easily add the sound of the Pro One to your music!

Lookup Sequential Circuits Pro One Prices

The link above will take you to an eBay search for this synth to see active listings with more images, specs and information. If you don't find it there, try looking in our forum marketplace. Our marketplace gets thousands of visits every week so make sure to check back often if you want to buy or sell a synth.

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Are you looking to buy or sell a Sequential Circuits Pro One? Post an ad in Gear For Sale or a request in Gear Wanted. For spare parts and repair services check out Gear Services & Other Goods. Our forums also has a Buyer’s Guide section where you can ask for advice on buying synthesizers.

70 Visitor comments
a beautiful sounding time bomb
August 7, 2013 @ 3:46 am
@ bumbaclart

Thanks for your concern, and of course you are correct! I assumed because the Pro-1 is all wood and plastic that I would be OK but the general opinion is that it's still dangerous. SO - I have now modified an audio cable which has done the trick!

Basically a twin core shielded cable where I took the 1 end off and replaced with a mono jack plug (for the Pro-1 end) and joined the earth and the other wire (no idea what it's called) together. The hum has now gone and I'm still safe now that I attached the earth cable to the plug again! Absolutely adoring my Pro-1! Cheers!
July 28, 2013 @ 8:00 pm
@a beautiful sounding time bomb carefully disconnecting the earth. The only thing worse than an annoying hum from a Pro One is death :)
a beautiful sounding time bomb
July 26, 2013 @ 7:21 am

1) Took her apart and carefully cleaned the keyboard contacts with an eraser and some servisol - fixed!
2) Scratchy pots and switches are all OK now after a few hours use - fixed
3) Mains hum fixed by simply unplugging the ground wire from the plug - fixed!
4) Just have to replace a transistor to get the noise up to full level again and I'm home and dry.

So, seems like the most common problems are easily fixed. *Happy*

@ Clement. Get yourself a 'Kenton Pro Solo'. Works right out of the box for the Pro-1. Or just give it to me! ;op
July 22, 2013 @ 12:51 pm
This cult synth was using in POLAND! Kapitan Nemo using this synth to this day.
July 21, 2013 @ 10:25 am
I was fortunate enough to have been given one of these beasts lately - I've yet to actually open up the storage container and integrate it into my rig.
I may have to get myself something like a Doepfer Dark Energy to hook this into my MIDI setup, I know nothing about CV stuff - I don't know if there's anywhere in the UK to MIDI retrofit this beast but I'm reluctant to butcher such a classic.
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Rated 4.45 (885 Votes)

  • Check Price
  • The link above will take you to an eBay search for this synth to see active listings. If you don't find it there, try looking in our forum marketplace or post a wanted classified.
  • Specifications
  • Polyphony - Monophonic
  • Oscillators - 2 VCOs (CEM-3340 chips): : VCO A saw/pulse, VCO B saw/tri/pulse, Noise
  • LFO - saw, tri, pulse
  • Filter - CEM-3320 Filter chips: 4-pole lowpass with Cutoff, Resonance, ADSR Envelope, Keyboard Tracking
  • VCA - ADSR Env
  • Keyboard - 36 keys
  • Arpeg/Seq - Arepg: UP, UP/DOWN patterns, Latch mode; SEQUENCER: 2 patterns of pitch info only, 40 note capacity.
  • Control - CV/GATE
  • Date Produced - 1981 - 1984
  • Resources & Credits
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