“For sale by original owner, purchased 1986, serial #02241. Exterior condition: excellent; never left my studio – but diskette drive needs replaced (“Lh” locked head error msg, will not read disks). (There have been replacement drives on the market – also USB-based floppy emulators from companies like HxC and N-Drive that specifically support the Prophet 2000, but I have no experience with those.)
61-key velocity-sensitive keyboard (no aftertouch)
12-bit sampling at 42K, 32K, or 16K
512K sample memory (two banks of 256K)
8-voice polyphony
Great-sounding analog VCFs (with resonance) and VCAs
Samples can be mapped into 8 layers across keyboard
Loads samples via internal 3.5” diskette drive (or MIDI Sample Dump Standard, SDS, if you can find appropriate software)
Built-in arpeggiator
MIDI In/Out/Thru
Original footpedal & approximately 100 sample diskettes (3.5”) included. (Can’t guarantee that 100% of them will read, given their age and because I can’t load them with its current floppy drive – however, approximately 35 backup copies—smaller boxes in the photo—are also included.)
Spring for pitch-bend was replaced.
No original manual, but PDF copies are easily available online.” Click here to visit listing on eBay
“This is for a used Sequential Circuits Six-Trak Vintage Analogue Synthesizer. The body is in decent shape has some nicks and scuffs as shown in picture but nothing major. Keys work perfectly, sounds awesome. The speed knob works fine but i think it has been replaced as it’s a little wonky but still works fine(right knob shown in picture) The 6 key works but sometimes needs to be pressed hard and last-the rubber around the end of the outlet plug is starting to degrade as shown in picture. All that said still works good and sounds amazing.” 
” You will not be disappointed from the big rich tones that this unassuming synth puts out. One of the original predecessors to the Dave Smith prophet, this synth has 100 presets that give off that quintessential 80’s sound with looks to boot. From funky to spooky this synth will definitely make you think of soundtrack to stranger things. it has a built sequencer that features 6 banks you can store or stack tracks in. I can’t even begin to describe how BIG of a sound it has, it gives my Roland Juno 60 a run for its money. Minor scuffs and scratches that would be common for a synth of its age. (see photos)” 
“This Six Trak is in very good condition and working perfectly. All controls have great feel and respond accurately. All lights fully functional. All ports and jacks in great shape and connect without issue. Sound is strong and clear. Keys straight and play nicely. Some scuffs and dings on the wood end panels and general signs of age, but overall in very good physical condition. ” 
“First class condition example of this iconic synthesizer.” 
“I’m selling my beautiful Sequential Circuits Six-Trak. This unit has a few dings and scratches due to it’s age, but as you can see in the pictures, it’s gorgeous. All functions and lights on this synth work great. It sounds great too! I’ve programmed some patches on it, but the rest are up to you” 
“Missing buttons for track 5 and 6 and also sound select 1 and 3, transpose and time button also missing. They are just simple rubber buttons and should be able to be replaced if you can find some. The knob for the master volume is also missing.
“For your consideration is the Sequential Circuits Prophet 5 Rev 3.3. This Prophet 5 has just returned from having a full service, from the country’s top Prophet tech, including some upgrades including: MIDI, ROM upgrade, expanded memory, a few CEM chips replaced, all new keyboard bushings, and IEC power cord. The original manual and data cassette are included as well. There are some cosmetic issues, so please look over all of the large, high-quality photos included in the listing.” 
” Six-Trak Sequential Circuits Synthesizer Keyboard. This unit has a few dings and scratches due to it’s age, but as you can see in the pictures, it’s gorgeous!!! All functions and lights seem to work on this synth and it sounds great too!!!” 
“Very recently serviced (30 days ago by SD Machines in Miami) Sequential Pro-One with case and owner’s manual. Everything works. In very good condition. It has a new transformer, new power switch, all keyboard contacts have been cleaned, new bushings, all keys aligned and calibrated. There is a chip in the paint next to the LFO amount knob (see picture). The Modulation wheel broke in two and has been glued together (see picture) The inner foam of the case is not the original one (see picture)” 
“In like-new condition, except for minor crack in power cord where it meets the unit(pictured). Never gigged. Original owner. All documentation included. Original flight case included.” 
“This unit is in almost new condition and works flawlessly. This is a great and rare find. Comes with original manual and full original library of samples on 3 1/2″ Floppy and replacement Floppy Drive.” 
“Good condition. Everything works. Includes power supply + extended sound cartridge. Comes with original box.” 
“This Six Trak is in very good condition and working perfectly. All controls have great feel and respond accurately. All lights and screen fully functional. All ports and jacks in great shape and connect without issue. Sound is strong and clear. 
” Here we have a rare Sequential Circuits Midi Voice Expander synthesizer from 1984, made in San Jose Ca. I hooked up a pair of vintage headphones to this synthesizer and all the keys and button appear to be in working order. There are a few scratches and marks on the surface, but nothing that affects performance, please see pictures. ” 
“Overall very nice condition. Has new key bushings and new battery. Action now very smooth throughout. Lowest G#/Ab has some clacking, note plays fine otherwise. Will ship in flight case.” 
“MINT- RACK FACE. When installed in an equipment rack, instrument appears MINT-. Rack Face is Mint except for a faint 2 MM scratch below the Envelope Group Rate button, faint 2 MM scratch to each knob, and minor oxidation of Vector joystick stalk (not joystick end). Instrument case sides, rack ears, top and bottom have scratches from installation in equipment rack. Instrument case sides, top and back have minor paint fading. See photos!” 
“Up for sale is a highly modded and amazingly cool Sequential Circuits Pro One. 
“This unit is used, but it is fully functional and has been recently serviced, has new battery for the memories which will provide years of trouble-free service. The power supply capacitors have also been replaced to ensure quiet operation.
“SCi Prophet-600 programmable polyphonic synthesizer
“This item was part of an estate sale of a musician friend who passed on.
” Rev. 3.3 ( 120 programmes ) Museum piece condition ! Hard to find a scratch , even underneath. The synth was given a full professional service just last month , new set of bushings , new battery , re capped , calibrated etc. Included in the sale is a comprehensive long term survival kit , consisting of several CEM chips , potentiometers , switches etc. Also comes with a new custom made padded bag , and an original manual. Over the last 30+ years i have played and owned several Prophet 5s , but have never seen one as nice as this.” 
“A nice condition Prophet 600 with the Gligli mod. This synth is sooo warm compared to modern synths. Just had it tuned up by The sequential guy here in the Bay Area. The Gligli mod changes up a few of the functions some of the knobs do so make sure to download the Gligli manual to know what your twisting. As with all vintage analog synths, let her warm up for at least 5 minutes to let the oscillators tune. It’s with a heavy heart that I sell this wonderful machine.. ”
” A very capable synthesizer with 99 presets, full parameter control, 6 voice polyphony w/unison, simple classic design, and a six track sequencer built in to the synth! ” 
“This Vintage Six-Trak Synthesizer is fully functional and in Very Good to Excellent Condition. The synth has been well taken care of with all knobs and pads intact. The wood side panels and keys are clean. The keyboard will come in a RoadRunner Flight Case measuring 29 x 18 inches. ”
“This unit is in almost new condition and works flawlessly. This is a great and rare find. Comes with original manual and full original library of samples on 3 1/2″ Floppy and replacement Floppy Drive.” 
“Vintage Sequential Circuits Pro One Analog Synthesizer in great condition. Legendary synth used by everyone from Depeche Mode and New Order to Prince.” 
“This unit is in almost new condition and works flawlessly. This is a great and rare find. Comes with original manual and full original library of samples on 3 1/2″ Floppy and replacement Floppy Drive.” 
” Sequential Circuits Six-Trak Vintage Analog Synthesizer. In excellent condition. Everything works on this synth. Volume control is clean, no noise at all…. Thanks for looking!” 
“SEQUENTIAL CIRCUITS PRO ONE SYNTHESIZER
“Sequential Circuits Prelude Synthesiser. Very rare analogue keyboard.Very good condition for a synth of this age. There is a small chip in the front of one of the keys as shown in photos, and the second D doesn’t work. I’m sure this is not a big job for someone who knows what they are doing. ” 
“Six-Trak Synthesizer – Everything works and is in Very Good Condition. Midi settings all set to factory settings using the midi ports. This synth has been well taken care of and all knobs and pads feel like they have experienced low use. The wood side panels are in great shape and the keys are clean. The Inside shows no sign of repairs or abuse. Clean inside and out. Please see the photos. ” 
“SN/???
“This unit is in almost new condition and works flawlessly. This is a great and rare find. Comes with original manual and full original library of samples on 3 1/2″ Floppy and replacement Floppy Drive.” 
“Sequential Circuits Pro One Analog Monophonic Synthesizer Fatar Keybed Turbo CPU MIDI