Sequential Circuits Six-Trak

” For sale, a Sequential Circuits SixTrak polysynth in full working order and great cosmetic condition. These synths are massively under-rated and no doubt will eventually appreciate in value the way their fellow eighties US-made polysynths did long ago. Six oscillators, multi-timbral with built-in sequencer and arpeggiator, what’s not to like? The only thing that lets it down is parameter editing, which is done via single data knob however there are external hardware add-ons that can transform this too.

This one has the latest v14 firmware installed – this allows you to select patches via the data knob (rather than by the numeric pad) and makes it much more fun to play with. It also adds a unison detune mode and a few other goodies.

This unit is in excellent cosmetic condition (only flaw is a very small chip on the left end cheek) and fully functional. It has just come back from Cyberwave EMS where it was given a repair and check-over. So now ready to be fully appreciated again.” Click here to visit listing on eBay

Sequential Circuits Prophet 2000

“The funky Sequential Circuits Prophet-2000 synthesiser.

An interesting early sampling keyboard from the 80’s.
Velocity sensitive, 8-note polyphonic, analogue machine.

All keys working (tested today!) etc etc.
In reasonable condition, just a minor few marks here and there as shown in the pics. The floppy drive MAY not be working correctly…I only have two discs to try to load from and the load command does signal a movement to the drive but doesn’t seem to achieve a successful load…so today I’ve just been testing with the 12 ROM sounds. The touch sensitive panel seems to be fine…….Sample input NOT tested.” 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 Prophet 600

“The synth has recently serviced with new battery, numeric membrane panel, and recapped power supply and voice card. Excellent working condition and only a few marks as shown. It has the GliGli upgrade and also have kept the original chip just in case you want to swap it back. The synth has been factory reset with the original patches loaded.

I did have a Prophet 5 before this and can’t really tell the difference to be frank. As some of you may already know the P 600 was the first synth to have Midi installed. Hats off Dave Smith. This is one of the most underrated synths ever! Maybe done purposely?! ” 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 Prophet 600

” Sequential Circuits – Prophet 600 synthesiser with brand new Gligli Update.

The Prophet has just had a service and MOT from Andy at Synthprof (I shall include the receipt £360 in the sale) and is future-proofed for your peace of mind.

Comes in new custom hardcase. Synth is fully working and is in unbelievable condition with only tiny blemishes, to be honest it looks like it just left the factory.

The pictures should say it all…What a thing to find one in this condition, Gligli firmware updated, serviced and future-proofed by Synthprof.” 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 Prophet 5

” Sequential Circuits Prophet 5 rev3.2 with MIDI + new key OEM Bushings + spare DAC 71 Chip. Excellent condition. Fully functional. Serial Number 3069

Includes original manual, power cord, spare authentic Burr Brown DAC 71 chip, and all replaced components completed throughout its maintenance. All maintenance receipts included for your records as well.

All buttons, knobs, wheels, display, and inputs work. Some pots have slightly more resistance than others – but all work completely. This is the original wood of course, which looks great. Keyboard action is wonderful and responsive. All badges are original. Underside has some scratches, which is cosmetic and how it looked when I originally purchased it in 2001.

Maintenance Record:
2009 = performed major overhaul of all controls by Davidson Electronics. Replaced missing screws. Resoldered numerous poor and weak connections.
2010 = Prophet 5 Factory MIDI Kit from Wine Country purchased.
2010 = Spare Burr Brown DAC-71-CSB-I D/A Converter chip purchased to ensure longevity and future proof.
2013 = Installed MIDI kit, tested all functions, installed and configured all NEW key OEM bushings. Fully tested. All work by Davidson Electronics.

Prophet will be shipped in a double wall cardboard box internally wrapped in bubble wrap plus peanuts for ultimate protection.
Double wall cardboard box was purchased locally from Packing Supply Depot (https://www.packagingsupplydepot.com/48x24x12-DoubleWallBox.aspx). If you are in/close to the 11803 area code I am happy to do local pickup.” Click here to visit listing on eBay

Sequential Circuits Six-Trak

“For sale is a vintage Sequential Circuits Six-Trak. The Sequential Circuits Six-Trak Polyphonic Synthesizer may be labelled as a “beginner model” by the company, but the features and functionality make it a prime choice for any synth enthusiast. Built with 48 velocity-sensitive keys and the same Curtis circuitry found in the company’s more expensive models. This Six-Trak exhibits some heavy cosmetic wear like rusting on the chassis and scratches on the side wooden panels. It’s not in the prettiest cosmetic shape, but it is completely functional and works perfectly.” Click here to visit listing on eBay

Sequential Circuits Prophet 2000

” The funky Sequential Circuits Prophet-2000 synthesiser.

An interesting early sampling keyboard from the 80’s.
Velocity sensitive, 8-note polyphonic, analogue machine.

All keys working (tested today!) etc etc.
In reasonable condition, just a minor few marks here and there as shown in the pics. The floppy drive MAY not be working correctly…I only have two discs to try to load from and the load command does signal a movement to the drive but doesn’t seem to achieve a successful load…so today I’ve just been testing with the 12 ROM sounds. The touch sensitive panel seems to be fine…….Sample input NOT tested.

Comes with original manual and a couple of floppy discs (sounds!!)” 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 Six-Trak

” I originally bought this to do a full restoration on, but other things have come up and I must pass this on to someone else

Here are a few things that need to be brought to attention:

The previous owner had used wire nuts to connect the power cord adapter. I would not recommend keeping it like this as you could pull the wires apart if you put enough stress on the cord! I am including a pair of power cord secure fastener pieces (see pic).

All the rubber key bushings had dry rotted and had to be removed. I actually could not find a source yet to replace them or come up with a better solution maybe. I have been plugging a midi controller in and playing the synth as a module. You can still play these keys, but they feel really bad without the bushings. Plus, you could scratch the keys on the bottom as they are coming into contact with metal.

I soldered in a CR type battery holder. I was able to load a sysex of the factory patches via midi and everything worked great!

The modulation wheel seems to not be working at the moment. While this synth sounds great I have noticed a strange sound introduced when you turn the track volume and speed volume knob.

I had to replace a knob and it sticks up a little higher, but works fine. The record LED had to be replaced and is a little brighter than the rest. It’s fine cuz it doesn’t stay lit long. You use it for control functions (see manual)” 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

Sequential Circuits Pro-8

“1984, Japanese market version of the split 8. 1984. Comes with a 240v transformer. This is in very good condition, looks nowhere near 37 years old. everything works apart from one LED (no 8). This is a great synth that few people have heard. It is capable of some amazing sounds especially in double mode which allows you to stack two different patches on top of each other. You need to be quite experienced at programming to get the best out of this as its quite tricky.” Click here to visit listing on eBay

Sequential Circuits Six-Trak

“I originally bought this to do a full restoration on, but other things have come up and I must pass this on to someone else

Here are a few things that need to be brought to attention:

The previous owner had used wire nuts to connect the power cord adapter. I would not recommend keeping it like this as you could pull the wires apart if you put enough stress on the cord! I am including a pair of power cord secure fastener pieces (see pic).

All the rubber key bushings had dry rotted and had to be removed. I actually could not find a source yet to replace them or come up with a better solution maybe. I have been plugging a midi controller in and playing the synth as a module. You can still play these keys, but they feel really bad without the bushings. Plus, you could scratch the keys on the bottom as they are coming into contact with metal.

I soldered in a CR type battery holder. I was able to load a sysex of the factory patches via midi and everything worked great!

The modulation wheel seems to not be working at the moment. While this synth sounds great I have noticed a strange sound introduced when you turn the track volume and speed volume knob.

I had to replace a knob and it sticks up a little higher, but works fine. The record LED had to be replaced and is a little brighter than the rest. It’s fine cuz it doesn’t stay lit long. You use it for control functions (see manual)

This little beast weighs about 16 lbs. I will pack and ship with the utmost care.” Click here to visit listing on eBay

Sequential Circuits Prophet 5

“PHYSICAL CONDITION: Very Good – There are some minor scuffs and dings around the device. The Prophet-5 logo on the front of the device has slightly faded as well. Otherwise, everything is intact, looking nice, and ready for action. The overall physical condition is very good.

WORKING CONDITION: Very Good – Just serviced and given new key bushings. All keys and controls are in fine working order. Each parameter is fully functional and the presets sound great. Overall, the working condition is very good.” 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

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 Prophet 5 Rev 3.2

” Sequential Circuits Prophet 5 rev3.2 with MIDI + new key OEM Bushings + spare DAC 71 Chip. Excellent condition. Fully functional. Serial Number 3069

Includes original manual, power cord, spare authentic Burr Brown DAC 71 chip, and all replaced components completed throughout its maintenance. All maintenance receipts included for your records as well.

All buttons, knobs, wheels, display, and inputs work. Some pots have slightly more resistance than others – but all work completely. This is the original wood of course, which looks great. Keyboard action is wonderful and responsive. All badges are original. Underside has some scratches, which is cosmetic and how it looked when I originally purchased it in 2001.

Maintenance Record:
2009 = performed major overhaul of all controls by Davidson Electronics. Replaced missing screws. Resoldered numerous poor and weak connections.
2010 = Prophet 5 Factory MIDI Kit from Wine Country purchased.
2010 = Spare Burr Brown DAC-71-CSB-I D/A Converter chip purchased to ensure longevity and future proof.
2013 = Installed MIDI kit, tested all functions, installed and configured all NEW key OEM bushings. Fully tested. All work by Davidson Electronics.”
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.” Click here to visit listing on eBay