MATRIXSYNTH

Sunday, October 19, 2025

Original Black Oberheim TVS Two-Voice System

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.

"One of very many items from Calum Hunter's superb home studio - and probably the jewel in the crown. This is a rare black version of Tom Oberheim's classic original Two-Voice synth. Cosmetically it looks a bit tatty at first glance - but on closer inspection, the bad areas where the paint has come off in places are all just on the chassis surrounding the SEMs and sequencer. Oberheim's preparation of these areas was obviously not up to their usual standard. Those pieces are usually white, and they simply over-sprayed them without preparing the surface well enough. In contrast, look at the black section immediately above the keyboard, which is really good.
All the modules (the important bit) are actually in extremely good condition - and apart from the sequencer having four little knob caps missing, near mint.

It would be simple to respray the bad chassis bits if you wanted. The tolex, keys and case hardware are pretty good for their age. There is no lid. The mains socket has been replaced with a safer IEC one. Voltage (TBC) is UK /European.

It has been tested by Audiocircus and is sounding great."

PWM Malevolent Semi-Modular Analog Keyboard Synthesizer

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via this listing

Additional Perfect Circuit listings

Moog Source Analog Keyboard Synthesizer SN 2041

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via this listing

Additional Perfect Circuit listings

Korg SB-100 Synthe-Bass SN 750076

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


via this Reverb listing

"I bought this from analogia.pl (i.e., Maciej Polak, check out his album 1977!) in 2022, serviced and converted to North American power. This synth is a little limited, but it sounds great and the portability can't be beat. It also has two features that (as far as I know) are unique to this model among early Korgs: the "bender" buttons and the "Phaser" waveform. As far as I can tell "Phaser" is a very nicely dialed-in pulse width modulation that sounds especially nice in the lower registers.

No major issues in testing, but two notes:

The output jack was a little intermittent when I started testing, but after working a 1/4" plug in and out of it the signal is solid. Guessing it was a little dirty and could eventually use a cleaning if you're handy. The "Traveller" slider is a little stiff around the center of its travel. All audio passes great, so this is really a "feel" thing and something I've also noticed on some (but not all) other early Korgs. In great cosmetic shape overall, but there are many little blemishes and signs of wear, which I tried my best to capture in the photos."

Rare Vintage KORG KEIO (?) CHECKMATE Drum Machine

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via this Reverb listing

This appears to be the first one to be featured on the site. It looks a bit like the Wexler ROCKMATE. Teisco made a CHECKMATE keyboard. You can fhand a handful of posts mentioning CHECKMATE here.

Details via the listing:

"A vintage Checkmate drum machine, a true gem from the early days of rhythm boxes. This unit is as much a visual statement as it is a piece of music history: with its golden front panel and large knobs, it’s a guaranteed eye-catcher in any studio or collection.

Fully serviced: all electrolytic capacitors have been replaced, ensuring reliable operation.

Everything works as it should – all rhythms, switches, and controls have been tested.

Runs on a single 9V battery inside the unit, making it portable and hassle-free.

About the Checkmate

The Checkmate belongs to the family of early preset rhythm machines from the late 1960s/early 1970s, often linked with Korg’s DoncaMatic line. These units were designed for accompaniment but quickly became collectible for their quirky analog character and stunning design.

Limited but charming selection of preset rhythms.

Simple analog sound circuitry with a warm, nostalgic tone.

Rarely seen today, making it highly desirable for collectors of vintage drum machines.

Why You’ll Love It

While it won’t replace a modern drum computer in terms of versatility, the Checkmate delivers something unique:

A rare piece of music history that shaped the early years of electronic rhythm.

Unmatched aesthetics – the gold panel and oversized knobs look fantastic both in use and as a display piece.

Collector’s must-have – these machines are increasingly hard to find in good working order.

If you’re a vintage synth/drum machine enthusiast, this is a rare opportunity to own a serviced and working Checkmate drum machine. Perfect as a collector’s item, studio conversation piece, or source of authentic retro rhythms."

MFB 501 Analog Drum Machine – 64 Presets, Rare Odd-Meter Rhythms, Works Perfectly

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


via this Reverb listing

Mode Machines Seq-12

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


via this Reverb listing

"corners of the face plate are crushed. still able to be installed into a rack space without issues. Otherwise flawless. Comes with eu power supply and us adapter.

This is such an awesome sequencer. perfect solution for sequencing multiple channels of a drum synth or expander. Each channel has its own cc parameter lock style sequencing and pattern chaining capability. It’s a good balance of intuitive, quick, and deeply complex."

Octave Electronics Cat SRM/II w/ Original Box & Manual

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


via this eBay listing

"Cat SRM/II by Octave Electronics 1983
Vintage, monophonic analog synthesizer with three-octave keyboard.

Two analog VOC's for creating thick, rich sound.

VCO 1 with mixable saw, square, and triangle wave with sub-octave. Square wave has LFO-controlled pulse-width modulation.

VCO 2 with mixable square and triangle wave with sub-octave."

Gorse Lathe - Drone demo


video upload by Synamodec

"GORSE LATHE is a handcrafted experimental synthesizer designed to explore the border between chaos and harmony. In this demo, we dive into its drone capabilities — sustained textures, evolving feedback, and harmonic movement that feels alive and unpredictable.

No sequences. No presets.
Just electricity, movement, and time.

🎧 Best experienced with headphones.

'Every drone is a landscape — you just have to listen long enough.'"

Also see Noise Sculpting with the Synamodec - Gorse Lathe.

Check with dealers on the right for price and availability.

Strymon SuperKar+ (Part 4) Chord Voice w/ Magneto, BitBox Micro, XPO, and ZPO


video upload by Rheyne

"The ‪@strymon‬ SuperKar+ Chord Voice through a Strymon Magneto. Percussion is from a BitBox Micro, bass is from a Make Noise XPO, and the background synth voice is from a Steady State Fate ZPO.

Loops are from Ableton Live, with a Korg SQ-64 acting as a MIDI to CV converter. Ableton's clock is randomized by CV Tools stepped-random LFOs. The Strymon Magneto is clocked by the kick drum trigger. Reverb is from Ableton Live. Recorded in one take.

SuperKar+ is a Eurorack voice module that uses Karplus-Strong synthesis to create the sound of plucked or bowed strings, struck or blown pipes or tubes, or a suite of other sounds."
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