Oberheim DX Full Restoration: How to Add MIDI, Upgrade RAM & Play Live

video upload by Nostalgic Explorer

"If you want to see how the Oberheim DX looks from the inside, how to clean the buttons, how to upgrade the RAM, and how to add MIDI to this classic drum machine, you're in the right place.

This machine came to me in pretty bad shape. Dirty on the outside, with some faulty buttons, and in serious need of some love. But honestly? It's not that hard to bring one of these back to life if you're careful and you enjoy working with vintage gear. And if you don't — stick around anyway, because it's super interesting to see these machines from the inside.

I'm walking you through the full process: deep cleaning, how to remove and clean the button contacts the right way (spoiler: cleaning the surface does nothing — you need to go under them), installing the Electrongate MIDI board and RAM upgrade so you don't need a battery anymore, and swapping the plastic panels for the beautiful wooden ones from Electrongate.

Big shoutout to Paul White, whose Electrongate videos were a huge reference for this build. I'm just a student passing the knowledge forward — go check his page, I'll leave the links below.

Once everything was back together and fully working, I put on a jacket — because if I'm performing original music for you, you deserve some respect — and played a live jam using the restored Oberheim DX, the Oberheim DMX, Moog Voyager, Rhodes Mark I, Oberheim Matrix 6R, Elektron Digitakt, and the Roland Space Echo RE-201."

Rick Wakeman's Polymoog 203a Restoration

video upload by synthpro

"Hey Guys,
In this video I take you through the restoration of Rick Wakeman's Old Polymoog that now belongs to Steve. (he purchased it from Rick and has a letter of authenticity) I preserved some areas while completely restoring and servicing others to keep this a historical unit but also very much usable.

This unit in particular would have been used on the YES album, 'Going For The One'.

Needless to say this was a very exciting project for me growing up listening to Rick Wakeman/YES as well as my appreciation for Dr. Dave Luce and the Polymoog.

Special thanks to Steve for giving me the opportunity to work on this Polymoog!

Thank you Rick Wakeman, for all the inspiration you gave me as well as million of others through your music and performances.

Sincerely,
Jareth

P.S- here are a few videos with Rick and the Polymoog:"



Playlist:

1. Yes - Going For The One Sessions Part 15
2. Yes - Wonderous Stories (Official Music Video)
3. POLYMOOG PROMOTIONAL FILM PT.1

Siel DK80 Battery Replacement

video upload by gstormelectro

"Audio + Video by G-Storm Electro c. 2026

In my previous video [posted here] you saw me tear down a Siel DK80. Today I am going to replace the lithium coin battery. Be sure to backup your patches to the cartridge before proceeding."

G-Storm Electro:
MUSIC https://gstormelectro.bandcamp.com/
BLOG http://gstormelectronica.blogspot.com/
LISTEN/DOWNLOAD http://soundcloud.com/gstormelectro
REVERB https://reverb.com/shop/gstormelectro

Roland JD-990 Super JD w/ Vintage Synths Expansion Board SN ZE81890

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via this Reverb listing

Additional CONTROL Listings

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

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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."

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

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Dead Roland Juno 106 Repair - Synthchaser #178 video upload by Synthchaser

via this eBay listing

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KORG PS series divider chips! RARE

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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."

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Oberheim OB-8 Boards & Modwheel Section

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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"

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Sequential Circuits Prophet VS Keyboard to repair SN 1259

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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."

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

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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"

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Linn Electronics LinnDrum LM-2 Drum Machine SN 2161

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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"

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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"

Rare Moog MEMORYMOOG DISPLAY

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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..."

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Sequential Circuits Prophet 2002 SN 0263

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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."

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Moog Minimoog - Early Oscillator Board - Rev 2 - LM3046

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via this eBay listing

Additional Analog U.S. Listings

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Very early Synthi A -1971! s/n 4118

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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)."

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Three Phutney EMS clone PCBs, Tuned

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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."

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

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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."

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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"

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.

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