Sequential Circuits Pro One Project Machine

“Vintage Sequential Circuits Pro One Synthesizer. Unsure if item works therefore selling as is. May or may night work or need repair. Vintage 1980s synthesizer.

UPDATE 8/28/22

Been getting alot of questions so I took more pictures. This is my Pro one. Bought it new in the 80s at Sam Ash in Queens NY. Used it a few years at home only. It has been unused for over 30 years in storage at different locations. When I used it, it always worked. Looks like the fuse has fallen out and I don’t have another or know when it was lost. I’m assuming that’s all it needs but not sure” Click here to visit listing on eBay

Sequential Circuits Pro One

“Sequential Circuits pro one.

I bought this fantastic sounding mono synth about 20 years ago second hand.

The power cord is somewhat frayed where it meets the machine, but this causes no problems as yet in turning on the machine.

Also, the keyboard has some dust in it meaning that sometimes, if pressed hard some of the inputs on some keys stutter, due to the electrical connection.”

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Sequential Circuits Pro One

” This massive sounding classic analog beast was born August 1981 : ) As you can see it was very well cared for, it looks fantastic and it all works great! By far the best bass and lead machine. It even sounds a little bolder than the Prophet 5! I had a pro analog tech install new key bushings and give it a good once over. This synth plays, sounds and looks great! Nothing beats the classics!
I left a radio station sticker on the side left panel.. you can easily remove it if you wish.. i just kept in on there as it really reminds me of how awesome the 80’s were. BTW, this is an early serial J Wire edition.. not the problematic Membrane Keybed version which has issues.. happy happy!”
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Sequential Circuits Pro One

“Sequential Circuits Pro One Vintage Synthesizer.
This classic synth is renowned for its fat rich bass synthesis and much more,
The filter system has been copied by many but bettered by none.
The inclusion of an audio input gives the user access to the awesome filter
to process external sounds.
This synth was professionally serviced 6 months ago and is in great condition
there is a very occasional crackle from a pot and a rare miss fire from a key
but all these parts are still original and work exceptionally well for their age”
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Sequential Circuits Pro One

“The famous Sequential Circuits Pro One mono synth.

A classy 2 oscillator machine with a fabulous rich, deep, punchy, awesome sound.
In very good condition, not Mint, not Excellent, but certainly ‘very good’. Early J-wire model.
Set 220 volts (can be set to 110).

Sold as seen. One key has a previous glue repair on it as you can see in the pics but all keys working fine.” Click here to visit listing on eBay

Sequential Circuits Pro One

“Legendary analogue synthesizer from 1981. Without a shadow of doubt the most powerful mono synth ever produced. This thing is completely devastating for bass, but also excels at leads, drones, percussive sounds and all kinds of other complete madness. A truly wild and amazing instrument. The real deal – none of this modern clone/reproduction business. The synth was serviced a couple pf years ago and is working flawlessly (I can provide the service invoice). The synth is in immaculate condition cosmetically. High quality walnut end cheeks have been added, these were imported from the USA and were costly items alone. All in all for a 40 year old unit this is a really incredible example. An amazing and inspiring instrument but also a solid investment, the price of these things is rising all the time these days. Collection in person is ideal – but I’m happy to ship within the UK at buyers expense.”
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Sequential Circuits Pro One

“This one is in excellent cosmetic condition and working 100%. It is ready to be played and needs nothing! As the title says, this one has the Turbo CPU Upgrade with Midi. It has a custom midi bezel on one of the wood sides so there is no irreversible damage and misaligned holes drilled into the metal housing. It also has the Techsmechs TM-2 keyboard replacement. Please mail with any questions. Shipping to most countries! The shipping price listed is just an estimate. If it is less, you will be refunded. If you’re overseas, it may be more. Please keep this in mind. ” Click here to visit listing on eBay

Sequential Circuits Pro One

“This one is in excellent cosmetic condition and working 100%. It is ready to be played and needs nothing! As the title says, this one has the Turbo CPU Upgrade with Midi. It has a custom midi bezel on one of the wood sides so there is no irreversible damage and misaligned holes drilled into the metal housing. It also has the Techsmechs TM-2 keyboard replacement.” Click here to visit listing on eBay

Sequential Circuits Pro One

“The famous Sequential Circuits Pro One mono synth.

A classy 2 oscillator machine with a fabulous rich, deep, punchy, awesome sound.
In very good condition, not Mint, not Excellent, but certainly ‘very good’. Early J-wire model.
Set 220 volts (can be set to 110).

Sold as seen. One key has a previous glue repair on it as you can see in the pics but all keys working fine.” Click here to visit listing on eBay

Sequential Circuits Pro One

” Great condition Sequential Circuits Pro One vintage synthesizer, just serviced by Synthchaser. This is the nice J-wire keybed version, with the contacts just cleaned and smooth new bushings installed. Other work done included power supply recap, new power cord, cleaning pots & switches, and calibration. Road case has no foam, so synth will be packed well inside the case. See attached pictures. Local pickup is welcome and encouraged.” Click here to visit listing on eBay

Sequential Circuits Pro One

“Sequential Circuits Pro One. Completely overhauled and serviced by top industry professional. Works amazingly. I have made some videos on YT of it in action. Search Pro-One Awesome Synth Power. Used on Goldbug – Whole Lotta Love for the synth solo and intro to b-side. The modulation matrix enables FM synthesis as well. You can see why Yamaha had to make an FM synth after this was invented, but a digital synth is no way as instant or as much fun or as powerful as this. There is possibility for at least three operators (as they are known in the Yamaha-speak) and of course it is also a punishing straight analogue synth to rival the Mini Moog. ( But there’s no FM on a Mini Moog.) Also available Roland MPU 101 in separate listing for if you need MIDI control. What more can I say? Been postponing selling it as enjoyed making the online videos so much. Would probably recommend pick-up in person if you can. (However, all my items are packed like Tutankamun and never had a problem yet, but it is serious vintage.) You can see in the video every module working including onboard sequencer and trigger/LFO functions. There are also explanations with the videos of how to use the matrix to get the FM synthesis.” Click here to visit listing on eBay

Sequential Circuits Pro One

“Great condition Sequential Circuits Pro One vintage synthesizer, just serviced by Synthchaser. This is the nice J-wire keybed version, with the contacts just cleaned and smooth new bushings installed. Other work done included power supply recap, new power cord, cleaning pots & switches, and calibration. Road case has no foam, so synth will be packed well inside the case. See attached pictures. ”
Click here to visit listing on eBay

Sequential Circuits Pro One

“Up for Sale, the Iconic Sequential Circuits Pro One Synthesizer. Fully functional and in good cosmetic condition. All the knobs, switches and keys produce sound. Although, all the keys produce sound, they are uneven. Some are higher than others. But, that’s not a issue because I usually use an external Arturia sequencer to program this synth via cv. I tried my frind’s Behringer clone next the original pro one qnd honestly idoesnt have the same vintage sound and power and the white noise is weak compared to the original. I’m selling it because I need money for rent otherwise I will keep this amazing beast. If you love that agressive metallic Depeche Mode sound or Berlin type techno this is the synth for you. It sounds like no other! ” Click here to visit listing on eBay

Sequential Circuits Pro One

“Sequential Circuits Pro One Fully disassembled, cleaned inside and out by Chris Hewitt at This Old Synth in San Jose, California. Working perfectly. Professionally installed the MTG MIDI + Turbo cpu in the SCI and the more desirable J-wire keyboard. This process was performed by an expert vintage synth tech. The end result is an instrument that’s better than the rest and is priced accordingly. Ready to play, no excuses. The wooden sides were replaced with brand new replicas made by a third party. Shipping is free within the United States. I’d consider shipping internationally if you paid for shipping costs.” Click here to visit listing on eBay

Sequential Circuits Pro One

“This is a Sequential Circuits Pro One synthesizer.
I am including a DI box in the package (as this eliminates audio hum).

The main circuit board was built in April 1982.
The serial number on the board and the one on the casing don’t match, which would suggest to me that the synth is a combination of two previous synths.
I have made a few improvements / fixes to the synth since I bought it:
A complete clean inside and out. All switches have been cleaned as have all key contact points.
Some capacitors have been replaced.
An internal ribbon has been replaced (bought from Wine Country Productions Inc).
I have bought wooden end cheeks for the synth, since these were missing.
I have also replaced a mod wheel (which was broken) with a clear acrylic wheel.
There is audio hum. Apparently, this is a very common feature of the Pro One and is due to a ground loop (an original design oversight).
The DI box eliminates the hum, and this is why I am providing the DI box with the synth.
I’ve tuned the synth using the variable resistors (pots). The tuning is pretty good across the keyboard, but will no doubt need readjusting from time to time.” Click here to visit listing on eBay

Sequential Circuits Pro One

“This is a Sequential Circuits Pro One synthesizer.
I am including a DI box in the package (as this eliminates audio hum).

The main circuit board was built in April 1982.
The serial number on the board and the one on the casing don’t match, which would suggest to me that the synth is a combination of two previous synths.
I have made a few improvements / fixes to the synth since I bought it:
A complete clean inside and out. All switches have been cleaned as have all key contact points.
Some capacitors have been replaced.
An internal ribbon has been replaced (bought from Wine Country Productions Inc).
I have bought wooden end cheeks for the synth, since these were missing.
I have also replaced a mod wheel (which was broken) with a clear acrylic wheel.
There is audio hum. Apparently, this is a very common feature of the Pro One and is due to a ground loop (an original design oversight).
The DI box eliminates the hum, and this is why I am providing the DI box with the synth.
I’ve tuned the synth using the variable resistors (pots). The tuning is pretty good across the keyboard, but will no doubt need readjusting from time to time.”
Click here to visit listing on eBay

Sequential Circuits Pro One

” Retro Gear Shop is a high-end boutique store located in Nashville, Tennessee.

Sequential Circuits Pro One #1015
For sale is a rare vintage Sequential Circuits Pro One analog monophonic synthesizer. This is a great synth that sounds excellent. Phat basses, leads and effects with a simple but fun built in arpeggiator and sequencer. This one is in excellent shape and fully functional. This is the more desirable J-wire keyboard version. A classic awesome mono-synth and worthy addition to any collector’s or sound designer’s studio.” Click here to visit listing on eBay

Sequential Circuits Pro One

“Sequential Circuits Pro One Vintage Synthesiser.

This Pro One is in great condition, with only the handful of minor blemishes that are to be expected on a vintage instrument of this age. I’ve done my best to picture these.

The keyboard and all other features work perfectly.

Unfortunately the two labels (Pro One & Sequential Circuits) have been lost over the years, but otherwise everything is as it should be.

Lovely piece of vintage gear and solid investment.” Click here to visit listing on eBay

Sequential Circuits Pro One

“For sale: A gorgeous example of the classic Sequential Circuits Pro One. Fully restored around 8 years ago by the famous Kent Spong on behalf of RL Music, it is almost blemish free apart from one or two minuscule marks. It was fully serviced only a week ago by Ben at Cyberwave Studios. Cleaned inside and out the j wire keybed has been cleaned and re set. The machine has been tuned and calibrated and a new noise generator installed. The Wooden end panels are undamaged and the switches and knobs are smooth and solid. It really is an absolute joy to play and sounds incredible. In its current condition you are looking at years of big bass, silky leads, punch and grit before you will need to have it serviced again. I really will be sad to see it go. ” Click here to visit listing on eBay

Sequential Circuits Pro One

“This is a Sequential Circuits Pro One synthesizer.
I am including a DI box in the package (as this eliminates audio hum).

The main circuit board was built in April 1982.
The serial number on the board and the one on the casing don’t match, which would suggest to me that the synth is a combination of two previous synths.
I have made a few improvements / fixes to the synth since I bought it:
A complete clean inside and out. All switches have been cleaned as have all key contact points.
Some capacitors have been replaced.
An internal ribbon has been replaced (bought from Wine Country Productions Inc).
I have bought wooden end cheeks for the synth, since these were missing.
I have also replaced a mod wheel (which was broken) with a clear acrylic wheel.
There is audio hum. Apparently, this is a very common feature of the Pro One and is due to a ground loop (an original design oversight).
The DI box eliminates the hum, and this is why I am providing the DI box with the synth.
I’ve tuned the synth using the variable resistors (pots). The tuning is pretty good across the keyboard, but will no doubt need readjusting from time to time.” Click here to visit listing on eBay

Sequential Circuits Pro One

” Up for sale is a highly cool Sequential Circuits Pro One with the proper J Wire Keybed. NOT the inferior membrane keybed.

As you can see this classic beast of a synth has been properly cared for all its life. Never abused or mistreated : ) It looks amazing and it plays amazing. There is nothing like a real Pro One. Basses, Leads, Efx, Swells and more… this synth has just a jawdropping sound. Perfect addition to any synth freaks collection.

It all works great, plays great and is properly tuned and scaled across many octaves. But as you’d know if you play, collect and use synths of this era. It MAY or may not need a scaling / calibration after being in transit.. just stating for full disclosure. THIS 40 year old electronic synthesizer is not applicable for returns for any reason. ” Click here to visit listing on eBay