Aries System 300 Restoration

These are photos from a restoration I recently completed. It is (as one might guess) an Aries System 300 that a client found at an estate sale. It had some water damage, and many of the jacks and switches were corroded beyond the level where a simple cleaning would have sufficed. I’ve posted some sonic demos to my soundcloud account, if you’d like to hear what an Aries synth sounds like.


Other than cleaning and refinishing, these are the replacements and mods that I made:

I replaced all of the jacks with new Switchcraft 35PM2A. These are almost identical to the original 42A jacks, but they are 3.5mm instead of .141″ (tinijax), so the synth will now play well with Eurorack synths, and it will be easier to find patch cables (good luck finding tinijax cables for a reasonable price).

For the switches that needed replacement, I used NOS Raytheon switches.

For the potentiometers that needed replacement, I used NOS Clarostat, Ohmite, Allen-Bradley, and Precision Electronics K series potentiometers, depending on the required taper and value.

I reconditioned the power supply caps and rebuilt the whole wiring harness, because the original had too much damage.

The Q feedback regulation OTA on the multimode filter had died, so I had to replace that.

In the modules I replaced all of the tantalum and electrolytic capacitors, and few ceramic capacitors whose leads were damaged.

This synth came with only one reverb tank, but fortunately I was able to locate another, so now it is complete.

It also came with only one VCO, but there was an empty slot where a second should have been. I filled it in with one from my collection. I plan to build myself a new one at some point.

I added three new modulation inputs on the VCOs: AC coupled 1V/Oct input, AC coupled FM (linear) input, DC coupled FM (linear) input. These add a lot of flexibility to the modulation options. I still need to make labels for these repurposed inputs.