“Nice condition not mint but very good. J wire low serial with chassis mounted psu. I’ve owned it for several years and it’s been regularly serviced I had the power cord removed and a kettle lead put in its place much safer and easier to move around. I also had the keyboard bushings replaced about two years ago as the keyboard was shocking plays nicely now. The pro one badge came off in the studio and is unfortunately now lost but they are readily available on Facebook if you feel you need it. I’ve recorded with it gigged with it and it’s never once let me down. It can be a bit picky with power as in it likes an nice clean supply, if you have a pc or laptop running on the same circuit the analog oscillators will create hum, this is a common thing with a lot of vintage synths it also likes a good 10 or 15 mins to warm up. I will be really sorry to see it go but it’s just not getting the use these days and I’m a player not a collector. ”
Click here to visit listing on eBay

“Used with scratches and scuffs. For parts/repair only. Powers on. Tones can be heard but there is heavy static.” Click here to visit listing on eBay

Pro One, Sequential Circuits @ 28 June 2018, Comments Off on Sequential Circuits Pro One

“Sequential Circuits Pro One analogue synthesizer – restoration project

All keys, dials and switches present. Woodenside panels, main body and branding stickers all in good condition.

Serial number 100-1795. This is the more desirable J-wirekeybed model (as opposed to the less reliable membrane keybed on serial numbers8500 and above), also with the power supply mounted to the chassis (as opposed to thepower supply mounted to the circuit board leading to breaks on serial numbers1500 and below).

Most dials and switches alter the sound that isproduced but this keyboard needs repair / calibration and a full service to getit back to working order. Keys 25-32, 35 and 37 are not responding. ”
Click here to visit listing on eBay

Pro One, Sequential Circuits @ 28 June 2018, Comments Off on Sequential Circuits Pro One

“Sequential Circuits Pro One Synthesizer – Serial No : 100-8249
On/Off Power Switch faulty so no power at the moment, therefore unable to check functions.
Used
Sold as seen
Buyer to collect.” Click here to visit listing on eBay

Pro One, Sequential Circuits @ 28 June 2018, Comments Off on Sequential Circuits Pro One

“Up for sale the iconic and fat sounding Sequential circuits pro one mono synth. In ok cosmetic condition and fully functional. All the buttons, switches and keys works as they should. Some pots are a little scratchy such as the noise pot. This synth sounds big and it really cuts trhough the mix. I really enjoyed the sequencer and the modulation features as well as the cv and gate interaction via external sequencers. Is great for bass metalic sounds, guitar type sounds, drones and fx anything 80s with a darker tone. I’m really gonna miss this one.” Click here to visit listing on eBay

Pro One, Sequential Circuits @ 14 June 2018, Comments Off on Sequential Circuits Pro One

“This Pro one is in nice cosmetic condition for it’s age,the top panel would be near perfect but for one blemish by the noise/ext knob.All lettering looks good, there is no static from the knobs,all keys trigger, the side boards have some dings and a small stain(they can easily be replaced w/ newly fashioned ones),the key action(not the signal)clatters kind of loudly(reliable speed is still good for me),though I’m unsure of what fix (cleaning,felt,rubber?)(How noisy are other Pro ones key actions?),I am sure of the cosmetic condition and the 100% sonic integrity,however I’m selling it as is(noisy key action, a quirk of a vintage synth?)” Click here to visit listing on eBay

Pro One, Sequential Circuits @ 14 June 2018, Comments Off on Sequential Circuits Pro One

” Still works though it needs a cleaning. Power cord was cut, I reattached it with wire caps so that I could make sure it worked, but it needs to be attached properly. Original wooden sides were replaced with custom wood. ” Click here to visit listing on eBay

Pro One, Sequential Circuits @ 07 June 2018, Comments Off on Sequential Circuits Pro One

” I am the original owner of this Pro-One. I have had it serviced at Pro-Audio Electronics of Tampa, FL in 2017 and it comes with a transferable, 90 day parts and labor warranty. Service included some replaced electronic parts, replaced keyboard pads, thorough cleaning and re-calibration. HISTORY: I bought it new in 1981. I used it on the road and in the studio. During that time the original pitch wheels that were made of plastic had cracked. I had replacement wheels made out of aluminum as seen in the photos. Nearly all of the case screws have been replaced because the originals rusted. I also removed the walnut end panels during its years on the road because I did not want to see them get scratched or damaged. The Serial Number is #0422. There are no MIDI retrofits or any other modifications done to this unit other than the service mentioned above.” Click here to visit listing on eBay

Pro One, Sequential Circuits @ 31 May 2018, Comments Off on Sequential Circuits Pro One

“I’m selling my pro one – Rev 1.2, which has the more desirable j-wire keyboard.

It’s in excellent condition and it has lived in a smoke free studio for the last decade.

I also have a prophet 5 which is my main synth and I just don’t use the pro one enough to justify keeping it.

It’s been kept in immaculate condition and the keys have recently had all the bushings replaced. It has just come back from a service where it passed with flying colours and it’s in perfect working order. ” Click here to visit listing on eBay

Pro One, Sequential Circuits @ 31 May 2018, Comments Off on Sequential Circuits Pro One

“The mighty sequential circuits pro one.This thing is so awesome hate to sell it!!! It has been fully reconditioned. Perfectly functioning, sound amazing and plays like a dream. The keys are smooth & even and have brand new Rubber. The circuit has been gone through with a fine tooth comb everything cleaned & deoxidized.No scratchy pots or switches. The panels have been gently oiled with Lem-oil and returned to their beautiful original glory.

Only issues the bottom has some scratches of no consequence(see pic# 6). And the right side wood panel has a blemish & couple of knicks (See pic 5). Here’s your chance to own a fine specimen of this classic synthesizer.” Click here to visit listing on eBay

Pro One, Sequential Circuits @ 24 May 2018, Comments Off on Sequential Circuits Pro One

“FOR SALE: a Sequential Circuits Pro One analog synthesizer with professionally restored electronics and a brand new 2018 Techsmechs keyboard installed- no j-wires to clean and/or replace, no faulty membrane keyboard- this has a brand new, newly manufactured, modern replacement keyboard installed and it is purely awesome; this synth’s keyboard mechanism is better than that of any other Pro One currently on the market.” Click here to visit listing on eBay

Pro One, Sequential Circuits @ 17 May 2018, Comments Off on Sequential Circuits Pro One

“I’m selling my pro one. It’s in excellent and it has lived in a smoke free studio for the last decade. I have a prophet 5 which is my main synth and I just don’t use the pro one enough to justify keeping it. ” Click here to visit listing on eBay

Pro One, Sequential Circuits @ 17 May 2018, Comments Off on Sequential Circuits Pro One

“Just in… a stunning Pro One Analogue Synth from Sequencial Circuits. Circa 1981, this synth is in excellent condition.
Complete with manual. This is pure 80s analogue so get your New Romantic gear on!! Very rare!!”
Click here to visit listing on eBay

Pro One, Sequential Circuits @ 10 May 2018, Comments Off on Sequential Circuits Pro One

“SEQUENTIAL CIRCUITS PRO ONE SYNTHESIZER
SERVICED AND TESTED BY THE ANALOG LAB IN EARLY 2017
NOT USED SINCE.
VINTAGE SYNTHESIZER
MODEL 100 – YEAR 1981
MONOGRAPHIC VERSION OF PROPHET-5
MODULATION IS FULFILLING
POSSIBLE TO CREATE A VARIETY OF SOUNDS.
SIMPLE SEQUENCER
ARPEGGIATOR LOADED
COMPACT-WEIGHS 14 LBS
22 WHITE KEYS
15 BLACK KEYS
NO BOOKLET OR INSTRUCTIONS INCLUDED
WILL SHIP PRIORITY MAIL,
INSURED AND SIGNATURE REQUIRED
vintage item, no returns” Click here to visit listing on eBay

Pro One, Sequential Circuits @ 26 April 2018, Comments Off on Sequential Circuits Pro One

“Here is the chance to get your hands on an all time classic. If you know what this is I don’t need to explain how good these are. It’s an inimitable synth capable of earth shattering bass and decent and genuine 80’s realness. Selling off my collection as they have become expensive ornaments! Badge has some wear to it other than than it’s in perfect condition. Serviced two years ago been in storage for the past year. Still tuned and working perfectly. It’s the J Wire model, which is the better of the two. ”
Click here to visit listing on eBay

Pro One, Sequential Circuits @ 19 April 2018, Comments Off on Sequential Circuits Pro One Project Machine

” I bought this very cheap with the intention of attempting to repair it, but don’t have the time or energy to mess with it.

It’s an early model, s/n 0606. The power cord has been cut, and I was told there are botched repairs inside. I have no idea to what extent.

Cosmetically, it’s fairly nice on the outside.” Click here to visit listing on eBay

Pro One, Sequential Circuits @ 19 April 2018, Comments Off on Sequential Circuits Pro One

“Hello, I’m selling my gentle used Pro One to make room in my home studio. Serial number is NOT scratched out but faded – reads 3098.

In fantastic working order, no issues to declare. No booklet or manual however the learning curve is minimal (plug & play). Manuals can be found online.” Click here to visit listing on eBay

Pro One, Sequential Circuits @ 05 April 2018, Comments Off on Sequential Circuits Pro One

“Good condition for it’s vintage. Refurbished with love and care and ready to be played, enjoyed and talked about in your studio”
Click here to visit listing on eBay

Pro One, Sequential Circuits @ 05 April 2018, Comments Off on Sequential Circuits Pro One

“Here is a vintage USA made Sequential Circuits Pro One synthesizer with it’s Anvil fiber case in good working condition, except some of the key contacts need cleaning. All knobs, switches, wheels and inputs/ouputs have been checked and work well.” Click here to visit listing on eBay

Pro One, Sequential Circuits @ 29 March 2018, Comments Off on Sequential Circuits Pro One

“A rare early serial number 1981 Sequential Circuits™ Pro One. Serial #249. Made in San Jose, California USA. This is the J-bar edition with a smooth, well functioning keybed. All keys engage and stay engaged. Synth is fully functional, as is the sequencer, no stratchy pots. Only a few scratches here and there (see last three pictures for scratch and dings). All in all in really great condition, a well keep and great example of a classic american analog mono. Comes with factory manual and ships free in the lower 48, International Shipping available.” Click here to visit listing on eBay

Pro One, Sequential Circuits @ 29 March 2018, Comments Off on Sequential Circuits Pro One

“SEQUENTIAL CIRCUITS
PRO-ONE SYNTHESIZER
INCLUDING ORIGINAL BOX AND MANUAL!!
Serial #6750 Circa 1982
*** THIS IS THE LOWEST PRICE I WILL GO- LAST CHANCE!! ***
*** FREE SHIPPING if final price goes over $1600
*** 2/16/ 2018 – I have added pics of the wood sides and the original box

This is one very CLEAN Pro-One!! Just serviced and ready to go! Every feature works great.
Not only that, I have the ORIGINAL MANUAL, WOOD SIDES and the ORIGINAL BOX with the correct serial numbers.
I also will include a spec sheet and pamphlet about the Pro One.

ALL of the oscillator chips were replaced (including the LFO) with NOS CEM chips.
Also the power supply was checked out, tuning calibrated and I have replaced ALL of the keyboard’s rubber bushings.
This Pro-One has the more desirable “J-Key” type keyboard which is considered much more reliable.
Once I replaced the bushings the keyboard was a LOT quieter and had a much better feel to it.
Repair work was professionally done by DFX in Salt Lake City (they make great boutique pedals too!).
Cosmetically a 9+ out of 10 it is a beautiful thing to behold! There are normal wear and tear marks on the wood sides (which can easily be sanded out).
Awesome powerful sound, very ballsy and aggressive with its famous modulation capabilities,sequencer and arpeggiator.
Note: There is one knob currently missing (the volume knob) but I will purchase a replacement for the winning bidder and have it sent directly to you.
This is a great example of 1982 synth technology, VERY RARE and COLLECTIBLE, ESPECIALLY SINCE I HAVE THE ORIGINAL BOX it came in and the ORIGINAL MANUAL as well.” Click here to visit listing on eBay

Pro One, Sequential Circuits @ 29 March 2018, Comments Off on Sequential Circuits Pro One

“Hi and thanks for checking out our Listing for

1982 Sequential Circuits Pro One 37 Key Synthesizer – Stunning!

In near mint condition, the only mark on the entire synth, is one tiny chip from the left hand wooden end cheek, otherwise, this superb one owner example is as new throughout.

Supplied with:

Original Operation Manual with the original purchase receipt stapled to the inside/back cover

A couple of original write-ups from the time of sale

A dozen or so sheets of Blank Preset diagrams to help you save your favourite sounds when you stumble across them.

Operationally, this synth is perfect and works as if it were brand new out of the box. We have made just one improvement. The keys were a little sticky from lack of use, so we’ve added individual cork buffers to every key. The key-bed was removed to fit these and they have been fitted between the key stops and the framework, giving the key return a much softer feel. All keys were then individually height adjusted so they rest perfectly flat across the register. We think there is no better example out there.” Click here to visit listing on eBay

Pro One, Sequential Circuits @ 22 March 2018, Comments Off on Sequential Circuits Pro one

“ALL of the oscillator chips were replaced (including the LFO) with NOS CEM chips.
Also the power supply was checked out, tuning calibrated and I have replaced ALL of the keyboard’s rubber bushings.
This Pro-One has the more desirable “J-Key” type keyboard which is considered much more reliable.
Once I replaced the bushings the keyboard was a LOT quieter and had a much better feel to it.
Repair work was professionally done by DFX in Salt Lake City (they make great boutique pedals too!).
Cosmetically a 9+ out of 10 it is a beautiful thing to behold! There is one scratch on the back, and normal wear and tear marks on the wood sides (which can easily be sanded out).
Awesome powerful sound, very ballsy and aggressive with its famous modulation capabilities,sequencer and arpeggiator.
Note: There is one knob currently missing (the volume knob) but I will purchase a replacement for the winning bidder and have it sent directly to you.
This is a great example of 1982 synth technology, VERY RARE and COLLECTIBLE, ESPECIALLY SINCE I HAVE THE ORIGINAL BOX it came in and the ORIGINAL MANUAL as well.” Click here to visit listing on eBay

Pro One, Sequential Circuits @ 15 March 2018, Comments Off on Sequential Circuits Pro One

“Having a studio clear out to make space for some new bits coming in.
Sequential circuits Pro 1 in beautiful woking condition.
i dont have to go into detail about this one as you all know what it can do if you have got this far!!
This synth is near mint for it’s age!” Click here to visit listing on eBay

Pro One, Sequential Circuits @ 15 March 2018, Comments Off on Sequential Circuits Pro One

” Pro One in need of some TLC. Fully working but needs a service and a new Octave switch. Comes in a Rod Argent Flight case (Needs new lining) and also a CV to MIDI external interface. ” Click here to visit listing on eBay

Pro One, Sequential Circuits @ 08 March 2018, Comments Off on Sequential Circuits Pro One

” It’s been recently serviced and is fully working, in perfect condition apart from some small scuffs on the wood. The External Input has been modded so that when you have something going through the Ext In you can trigger the filter and amp envelopes with the Gate In. I can ship if necessary but would prefer collection. ” Click here to visit listing on eBay

Pro One, Sequential Circuits @ 01 March 2018, Comments Off on Sequential Circuits Pro One

“Excellent condition. This is the more desirable J-Wire model.” Click here to visit listing on eBay

Pro One, Sequential Circuits @ 01 March 2018, Comments Off on Sequential Circuits Pro One

“Sequential Circuits Pro One in perfect playing condition and excellent cosmic presentation. This has been recently serviced by Austin’s prestigious Switched On synth shop to include improved noise source, cleaning, cleaned pots, tested keys, replaced mode switches, among other items. Everything works as it should. J-wire style keyboard works perfectly. Guaranteed not DOA.” Click here to visit listing on eBay

Pro One, Sequential Circuits @ 15 February 2018, Comments Off on Sequential Circuits Pro One

“Pro One Synthesizer, -w- Manual & Case Serial 8405

FEATURES:

Working perfectly
Great sounding dual VCOs, White Noise generator, 4 pole Filter, extensive Modulation to ADSR envelops
Sequencer (40 note) will transpose patterns to any key ‘on the fly’
Arpeggiator (latchable)
Control Voltage & Trigger input & outputs for interface with various modules
All original SCI knobs, and Control Wheels, fully operational
Keyboard -w- new keypads, gold J wires adjusted, (monophonic keyboard feels nice & responds smoothly)
Attractive tung-oiled wooden side panels
Made in San Jose, CA, USA & featuring original factory solder artwork on main circuit board ( Nome -w- mushrooms)
No cracks, pops or hums, clean line level output
On the advice of LA keyboard technician nothing has ever been squirted into the potentiometers. Operation of well made pots, has always eliminated any minimal oxidation. (plus, if it’s not broken … )

KNOWN minor ISSUES

Small nick in (right front edge) of wooden, side panel (see photos)
There are minimal scratches on bottom, (4) rubber feet are fine
Extra black-wire tie attached to outside of New power cord

BONUS

MANUAL – Original Sequential Circuits Pro One manual with rare decal of #1 billiard ball
Manual contains diagrams for Factory Patches, blank templates, and ‘Calibration’ instructions
CASE – fitted plywood case, used, but very functional. (Actually the case is responsible for the clean condition of this synth) ” Click here to visit listing on eBay

Pro One, Sequential Circuits @ 15 February 2018, Comments Off on Sequential Circuits Pro One

“This one is in excellent cosmetic condition and working 100%. Beside the servicing & internal restoration, the bottom metal chassis was professionally repainted and silk-screened as it was pretty ugly and scratched up. Internally, I decided to keep this one stock without adding midi. It is ready to be played and needs nothing!”
Click here to visit listing on eBay

Pro One, Sequential Circuits @ 08 February 2018, Comments Off on Sequential Circuits Pro One

“SCI Pro one J-Wire in very good condition, inspected, clean, full working order. Has been Pro serviced. Used in home studio and handeled with care.

-new keybushings
-keys washed
-calibrated
-Keybed cleaning
-Cleaning Key contacts.

You will receive:

SCI Pro One
Custom Flightcase
Manual
Power cord
Invoice”
Click here to visit listing on eBay

Pro One, Sequential Circuits @ 25 January 2018, Comments Off on Sequential Circuits Pro One

“SEQUENTIAL CIRCUITS PRO ONE SYNTHESIZER
USED —- BUT RECENTLY SERVICED BY THE ANALOG LAB.
VINTAGE SYNTHESIZER
MODEL 100 YEAR 1981
MONOGRAPHIC VERSION OF PROPHET-5
MODULATION IS FULFILLING
POSSIBLE TO CREATE A VARIETY OF SOUNDS.
SIMPLE SEQUENCER
ARPEGGIATOR LOADED
COMPACT-WEIGHS 14 LBS
22 WHITE KEYS
15 BLACK KEYS”
Click here to visit listing on eBay

Pro One, Sequential Circuits @ 18 January 2018, Comments Off on Sequential Circuits Pro One

“Pro One Synthesizer, (Good Working Condition ) Serial 8405
-w- Manual & Case

Being sold by original owner (long standing EBAY member), Used for graduate music program, composing electronic music and educational acoustics demonstrations. Confident next owner will enjoy performing and recording with this classic synthesizer.

FEATURES:

Great sounding dual VCOs, White Noise generator, 4 pole Filter, extensive Modulation to ADSR envelops
Sequencer (40 note) will transpose to any key ‘on the fly’
Arpeggiator (latachable)
Control Voltage & Trigger input & outputs for interface with various modules
All original SCI knobs, and Control Wheels, fully operational
Keyboard refurbished -w- new keypads, gold J wires adjusted, (monophonic keyboard feels nice & responds smoothly)
Attractive tung-oiled wooden side panels, well maintained
Made in San Jose, CA, USA & featuring original factory artwork on main circuit board ( SC Nome -w- mushrooms)
Featured on I-tunes release Sequenced Ostinatos (Six movements in multiple time signatures)

KNOWN ISSUES

Small nick in (front edge) of wooden, side panel
Extra black wire tie attached to outside of new power cord
Left case latch has dent, but still latches
When first purchased, I was excited & wrote a few (silly) things on the circuit board with a magic marker

BONUS

MANUAL – Original Sequential Circuits Pro One manual with rare decal of #1 billiard ball
Manual contains diagrams for Factory Patches, blank templates, and ‘Calibration’ instructions
CASE – fitted plywood case, used, but very functional. (Actually the case is responsible for the clean condition of this synth) ” Click here to visit listing on eBay

Pro One, Sequential Circuits @ 18 January 2018, Comments Off on Sequential Circuits Pro One

“SEQUENTIAL CIRCUITS PRO ONE SYNTHESIZER
USED —- BUT RECENTLY SERVICED BY THE ANALOG LAB.
VINTAGE SYNTHESIZER
MODEL 100 YEAR 1981
MONOGRAPHIC VERSION OF PROPHET-5
MODULATION IS FULFILLING
POSSIBLE TO CREATE A VARIETY OF SOUNDS.
SIMPLE SEQUENCER
ARPEGGIATOR LOADED
COMPACT-WEIGHS 14 LBS
22 WHITE KEYS
15 BLACK KEYS” Click here to visit listing on eBay

Pro One, Sequential Circuits @ 11 January 2018, Comments Off on Sequential Circuits Pro One

“I am reluctantly selling my Pro One. Between a friend and I we have had this classic for over 30 years.
Serial No 100- 4403
It has been in storage for several years and after plugging in to test, it has developed a couple of faults,

I want to be honest so I will list what the obvious defects as well as the good points to give everyone a good basis for decision

Cosmetically it is still In great condition for a big old monosynth from 1981
It will power up . the on/off switch on the back is stuck in “on”
The synth will work in drone mode , the keyboard does not appear to work.
The knobs and pots all seem to work ok, a few are a bit noisy , in drone mode you can hear the filters change, LFO etc
Both the pitch bend and modulation wheels work ok.
The keyboard has a few slightly wonky keys, but the last time it worked, all the keys worked fine.
There are scratch marks to the bottom of the casing from being on stands etc over time
The front panel is in very good condition with very few visible blemishes
The wooden end cases are also in good condition.
I have replaced the fuse holder and replaced the fuse, and I have downloaded a manual with the original 20 preset patches

I have taken the Pro One to a private keyboard repair centre, the guy seems to think it’s a voltage problem, but 35 year old mono synths were not his strongest point, but he said it would definitely be salvageable with the right knoweldge. ” Click here to visit listing on eBay