MATRIXSYNTH: synth guts

Showing posts with label synth guts. Show all posts
Showing posts with label synth guts. Show all posts

Thursday, April 23, 2026

Roland Juno-106 w/ ALL NEW Double Heart Voice Chips

Note: links to listings are affiliate links for which the site may be compensated.
video upload by Seventy Three Records Music Store



via this eBay listing

"This classic Juno 106 is in great cosmetic and operational condition. ALL voice / filter chips are working proper without any issues we we had them professionally replaced / installed by with Double Heart Audio Voice Chips (which are simply the best) this month. This synth was bought in the late 80s for a studio where it was used on many sessions. Always taken care of. Battery Voltage was checked and in spec, power supply checked and in spec. It was also fully calibrated. It is ready for years and decades of use.. ready for any synth lover's rig. We are pricing it pretty low considering it has the complete voice chip upgrade. And as you can see from the pics.. it looks amazing as well.. very well kept.. never gigged live!

If you've been waiting for a ready and steady Juno 106.. this is it."

Thursday, April 16, 2026

Roland Juno 106 Synthesizer - Serviced - New Voice Chips - Signed by Kip Winger

Note: links to listings are affiliate links for which the site may be compensated.
Dead Roland Juno 106 Repair - Synthchaser #178 video upload by Synthchaser



via this eBay listing

Wednesday, April 08, 2026

KORG PS series divider chips! RARE

Note: links to listings are affiliate links for which the site may be compensated.


via this Vemia listing

Click the auction link on top when you get there for additional listings.

"These are 12 (the full keyboard extension) extremely rare chips, perfect replacements for the unobtanium MM5823N built by NATIONAL SEMICONDUCTOR. The original ones do break after some years, these are made with new electronic components, so will last a life... Remember, if you have one of the following, you need them: these Ics are brand new ones, and are used on different types of synthesizers (Hammond X5,Korg PE-1000,PE-2000,PS-3100,PS-3200, PS-3300). I bought them for future maintenance of my PS 3200. Now it's gone."

Tuesday, April 07, 2026

Oberheim OB-8 Boards & Modwheel Section

Note: links to listings are affiliate links for which the site may be compensated.


OB-8 processor board via this Vemia listing

Click the auction link on top when you get there for additional listings.

"Oberheim OB8 processor board complete except for the eprom all ics was tested ok extremely rare to find"

Sequential Circuits Prophet VS Keyboard to repair SN 1259

Note: links to listings are affiliate links for which the site may be compensated.


via this Vemia listing

Click the auction link on top when you get there for additional listings.

Pic of the inside below.

"In very good cosmetic condition, complete but needing repair. More info: The prophet power on all the supply voltages are ok, and the Display turns on (need new backlight) but with all segments lit. The keybed need a new aftertouch sensor."

Sequential DrumTraks 12-Voice Drum Machine (Serviced) SN 06298 w/ Original Box

Note: links to listings are affiliate links for which the site may be compensated.


via this Reverb listing

Pics of the inside below.

"One of the earliest MIDI capable drum machines, the Sequential Circuits Drumtraks is punchy, unique, and will integrate effortlessly into a contemporary studio. The sound of this thing is fantastic, with 13 8-bit sample based drum sounds and a powerful pattern sequencer. This drum machine is fully tested and in great working condition. Serial No. 06298"

Monday, April 06, 2026

Linn Electronics LinnDrum LM-2 Drum Machine SN 2161

Note: links to listings are affiliate links for which the site may be compensated.


via this Reverb listing

Additional SYNTH CITY Listings

Pics of the inside below.

"1980s Linn Electronics LM-2 Drum Machine, fully serviced/restored in-house. Ready for studio action and sounds incredible. Serial No: 2161

-Refurbished 5VDC supply and installed new memory battery
-Replaced filter caps and supply caps
-Cleaned all buttons faders and pots
-Replaced (1) RIDE rom IC
-Calibrated 5v supply and voice settings"

Saturday, April 04, 2026

Synclavier II Hardware In 2 Minutes


video upload by Synclav com

"This is year number 27 for Synhouse.

Synhouse has fully restored and shipped many, many dozens of systems in the last three decades and this work continues in 2026.

Shown here is the testing of a Synclavier computer bin card set without needing the synthesizer voices yet (it ended up with 8 original style mono Synclavier II synthesizer voices). This Control Unit is used as a test box at Synhouse. Once testing was completed, the cards were moved to a freshly restored ATS 3-level enclosure chosen by the client.

Relatively few Synclavier IIs were made, and this is the super vintage hardware setup.

Synhouse stocks these systems and parts and Synhouse manufactures this hardware and has them in the Synclavier store on the Synclav.com website.

Video copyright 2026 Synhouse Multimedia Corporation"

Wednesday, April 01, 2026

Rare Moog MEMORYMOOG DISPLAY

Note: links to listings are affiliate links for which the site may be compensated.


via this Vemia listing

Click the auction link on top when you get there for additional listings.

"This is UNBTANIUM. An original, brand new (NOS) replacement for the display board for Memorymoog and Memorymoog plus! As you can understand, after so many decades these displays fail. After that, your Memorymoog fails. For ever. This is a unique opportunity to buy a NOS spare, genuine MOOG replacement, for a safe future of the Beast..."

Sunday, March 29, 2026

Sequential Circuits Prophet 2002 SN 0263

Note: links to listings are affiliate links for which the site may be compensated.


via this eBay listing

Pics of the inside below.

"Sequential Prophet 2002 with latest firmware 4.3B, expanded version with 8 out expansion. Basic testing done with midi keyboard and all patches play, sampler records and plays back. The buttons sometimes need another push to activate but all work and are responsive."

Saturday, March 28, 2026

Moog Minimoog - Early Oscillator Board - Rev 2 - LM3046

Note: links to listings are affiliate links for which the site may be compensated.


via this eBay listing

Additional Analog U.S. Listings

Friday, March 27, 2026

Very early Synthi A -1971! s/n 4118

Note: links to listings are affiliate links for which the site may be compensated.


via this Vemia listing

Click the auction link on top when you get there for additional listings.

Pic of the inside below.

"This auction is for an original 1971 Mk1 EMS Synthi A synthesiser, serial number 4118, in its Spartanite case. The case has a few marks and scratches as befitting a 55 year old instrument, but no chips or breaks. The latches, although showing some corrosion, work perfectly.
The Synthi front panel is one of the cleanest we’ve seen, being almost immaculate with virtually no panel marks and, unusually, no writing or marking absent or worn from the screen printing. In addition this example comes with the early chrome mirror finish knobs.

The internals are extremely clean and original with no modifications (see photo#4 now under the wrong thumbnail) and the unit has the genuine GE PA234 audio amplifier devices for the outputs and reverb.

The unit has been fully tested by one of the three or four people in the world who can call themselves EMS experts. It has been aligned and found to be working perfectly, and consequently given the original condition of the unit, no capacitors have been replaced. The original ones are working fine and show no signs of leakage or decay. However while the existing pots are electrically good with no scratchiness, some are a mechanically stiffer than current production models and the buyer might wish to have these replaced. This can be done at additional cost either here in the UK by EMS experts Lucid or by the buyer’s own engineer.

The Synthi comes with a full set of 20 patch pins and a new UK 240VAC mains lead (not shown). (Observant viewers may notice the absence of the usual Synthi A plastic name plate which usually adorns the outer case. This isn’t missing, but was simply never fitted as there are no holes for it, perhaps because of the early serial number. In addition the rear case is attached by four factory fitted screws and bushings, rather than the more usual arrangement of three)."

Three Phutney EMS clone PCBs, Tuned

Note: links to listings are affiliate links for which the site may be compensated.


via this Vemia listing

Click the auction link on top when you get there for additional listings.

"Set of Three Phutney PCB Cards – EMS VCS3 / Synthi A Clone A set of three fully built Phutney PCB cards for the EMS VCS3 / Synthi A. These are the highly regarded clone boards designed by Derek Revell, widely considered among the most accurate reproductions available for anyone wishing to recreate one of these classic synthesizers, or to replace cards in an original EMS instrument.

The boards were professionally assembled by an experienced audio engineer, using new old stock germanium and silicon transistors to get as close as possible to the character of the original EMS circuitry.

They have been extensively tested and calibrated in my 1975 EMS Synthi AKS. My original intention was to use them to build a VCS3 “Cloney”-style synth, but that project never materialised.

During testing, resistor values were carefully adjusted until the cards performed and sounded indistinguishable from the original EMS circuit boards.

The sale also includes: • Header and PCB solder-in edge connectors to simplify wiring during a build • A set of blue edge connectors with solder tags if you prefer the more traditional “old-school” wiring approach

All three boards are fully populated, tested, and confirmed working. As mentioned, they were bench-tested and run inside a working EMS Synthi AKS, allowing direct comparison with original EMS cards during calibration.

If you are planning to build a vintage EMS-style synthesizer, this is an excellent starting point, as the boards are already assembled, tested, and carefully tuned to match the performance and sound of a 1975 Synthi A / VCS3."

Thursday, March 26, 2026

Rare Custom DIY ARP-Style Analog Synthesizer – One-of-a-Kind Estate Find

Note: links to listings are affiliate links for which the site may be compensated.


via this eBay listing

"Offered here is a truly unique and intriguing analog synthesizer, discovered at an estate sale in Los Angeles belonging to a longtime record collector. This piece appears to be a custom-built or prototype-style instrument inspired by classic ARP designs—featuring elements reminiscent of both the ARP 2600 and later Odyssey models.

The layout, switching, and signal flow strongly reflect deep knowledge of vintage ARP circuitry, while the construction suggests a highly skilled builder with access to professional-grade metalwork and components. The unit is housed in what appears to be an ARP pedal synthesizer case, though the internal assembly is not permanently mounted—indicating this may have been a custom project or experimental build. It has one etched circuit board on a module and the rest are on perfboard with point to point wiring.

Notable features:

ARP 2600-style panel layout with Odyssey-style switching influences

Point-to-point wiring with included schematic diagram

Separate keyboard connected via cabling

Vintage analog components throughout

Powers on (unit lights up), though full functionality has not been tested

Whether this is a one-off custom build, a studio project, or an experimental instrument from a knowledgeable enthusiast, it represents a fascinating piece of analog synthesis history. With some restoration or calibration, it has the potential to become a highly expressive and unique instrument."

Tuesday, March 24, 2026

Mike's Multimoog Restore/Demo


video upload by synthpro

"Hey Guys,
In this video, I bring you along the adventure of a sick little Multimoog that now has a full bill of health. Thanks for watching!

Sincerely,
Jareth"

Monday, March 23, 2026

Sequential Circuits Prophet 2002

Note: links to listings are affiliate links for which the site may be compensated.


via this eBay listing

"Sequential Prophet 2002 with latest firmware 4.3B, expanded version with 8 out expansion."

Pics of the inside below.

Thursday, March 19, 2026

SP-1200 * PROTOTYPE * with Riley Smith (OG e-mu, Sequential Circuits)


video upload by Manuel Clement

"My friend Riley Smith walks you through my beautiful E-mu SP-1200 engineering prototype. Riley is a legend. OG from Sequential, decades at e-mu, and more. Enjoy!"

Wednesday, March 18, 2026

Alpha Juno VCF MOD


video upload by Maffez Synthmods

"Qiick an dirty demo of two modifications for the Roland Alpha Juno Series. 1. Self-oscillating filter, 2. Variable chorus depth. Check modwiggler forum under: https://www.modwiggler.com/forum/view..."

Monday, March 16, 2026

Gxmnopedie#1


video upload by sequentix

Yamaha GX1 with the lid up / open. Note the individual voice boards and ribbons.

Sunday, March 15, 2026

ARP 2600/3620 Duophonic Keyboard. Semi-Modular Analog Synth

Note: links to listings are affiliate links for which the site may be compensated.


via this eBay listing

"The ARP 2600/3620 Duophonic Keyboard is a vintage original semi-modular analog synth produced by ARP. With 49 keys and a semi-modular design, this synthesizer offers a unique blend of analog sound and modular functionality. It features input/output ports including CV out, trig in, CV in, gate out, gate in, and trig out, allowing for versatile connectivity with other musical equipment. The ARP 2600 also boasts pedal inputs, faders, built-in effects, and speakers, making it a versatile and powerful tool for creating a wide range of sounds and music compositions. Made in the United States, this classic synthesizer is still highly sought after by musicians and producers looking to add its distinctive sound to their work."

Pic of the inside below.

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