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.

68 Visitor comments
April 1, 2014 @ 9:09 am
All my other synths had patches stored in them so you keep flipping thru the patches till you find something you like and when you run out of sounds, you buy a new synth with more patches. Then repeat the process...... forever always wanting the newest synths for there new sounds!

Then I discovered analog synthesis thru the Pro-One and holy [beep] I was blown away. You can shape the sound from scratch like a sculptor would create a statue from a block of marble.

Custom Patches for the Pro-One are on my website
Electric City
January 3, 2014 @ 4:31 pm
Ladytron used a Pro-One on stage (and probably on studio) during "Light & Magic" tour. Emily Haines from Metric also used a Pro-One since 2001.
December 17, 2013 @ 8:47 am
@a beautiful sounding time bomb

I also have the "low noise oscillator level" problem on my Pro-One. Could you or someone please post how to fix it, like what transistor to use and how to replace it? It has been bugging me since 1983 when I bought it but did't realize it was actually a defect.
November 18, 2013 @ 9:47 am
Easily the first major monosynth that any serious collector should buy. Syncs well with most analog drum machines. Probably the best affordable cem based synth out there unless you found a ob1 and those are not even in the same price class usually. The pro one (especially the early ones with the 100k pots) are alot smoother sounding when tweaking than an ob1. The way that the pots adjust the frequencies is totally different. An ob1 always seems to adjust in steps and has a gritty texture while a pro one just hums along while being adjusted.
November 6, 2013 @ 4:31 pm
I just got the MTG TurboCPU, with MIDI+CV expansion, for the Pro-One.

Turns the Pro-One into a modern vintage monster.
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  • 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

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