Stroh Rare Prototype Analog FM/PM panel + Ian Fritz/UglySound Timbre Tantrum 2017 4U/Serge

Panel #1 (bottom) : Stroh prototype frequency/phase modulation panel: two VCO's with many waveforms each, sync, FM (lin/exp), PM (two inputs), very easy to get extreme modulations and "crazy" but useful sounds with the PM inputs, which I actually prefer to the FM ones.

The idea appears to be Yamaha style FM (which is actually PM), allowing very deep and extreme modulation but with 100% analog circuits.

I would suggest this thread for history and (partial) documentation: but you will also have a great time experimenting and figuring out your own uses. The thread possibly dates this system to 2017 though I'm not sure on this.

The middle section in the VCO's module (X/Y/Z) seems to be a ring modulator for X and Y, not sure what the Z input does, sounds like it mixes in directly but at a lower volume. then there are four VC Slope/envelope generators + CV mixer, then four VCA's and an output module.

Panel #2 (top): Many Ian Fritz designed circuits, all of exceptional quality, assembled by Uglysound. It takes too much to describe each function but the quality is quite good, each module alone provides an incredible range of useful timbral variation. Only thing i notice is Threeler filter 1V/oct jack seems not to work, BUT the variable VC control works fine and can be used instead -- there are CV mixers in this system to help as a workaround, for instance to mix an envelope and keyboard voltage. Other minor issue is a few knobs provide more resistance than others, but none of that

Cosmetically its in great shape overall, there is a small black marking on one of the side panels, a few minor nicks and scratches in the wood.

The system comes with its own Stroh power supply and cabling (pictured).