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
November 3, 2013 @ 5:08 pm
@ a beautiful time bomb

Cheers on getting your Pro up and running again! I would highly encourage you to revisit the keyboard contacts using Caig Deoxit D5 (red). It comes in aerosol or liquid and will improve the contacts greatly. Using an eraser is the worst thing one can do to electrical contacts as it damages the metal surface. Deoxit would be good for the pots also - the aerosol working the best in that application. Deoxit actually bonds on a molecular level with the metal surfaces increasing conductivity and protecting the surface from oxide build-up.
October 31, 2013 @ 12:45 pm
@Analogical Captain

Ozrics are one of my favourites too and the Pro One pretty much did 95% of all those freerunning arpeggio's that made up the unique Ozrics sound :)
Analogical Captain
August 20, 2013 @ 3:32 pm
One of the best decisions of my entire life buying a Pro One. I've been a fan of Ozric Tentacles for a very long time, and after 20 years it's great having THE synth which defined the sound of their earlier (and some of their later) albums. Mindblowingly psychedelic spacey noises, bubbles etc. The sequencer is limited but it's great you can change key and keep the arpeggiation. Love the glide control. and using the two oscillators so one is a fifth out from the other, making a dual harmony note on a monosynth. I don't care if it appreciates in value to £1 million - I'm NEVER selling it.
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 :)
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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
  • Resources & Credits
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