Category: ARP

It’s time to dig into my stash of ARP Quadras and get a couple of them overhauled and back out into the world. This Quadra was looking really sad, all of its slider shafts were sheared off, and it was shipped to me partially disassembled and in disarray. But the seller said it was working… NOT!

In this video I share (just some of) the ordeal it took to get this Quadra awesome again. Including refurbishing sliders, replacing broken slider shafts, repairing battery corrosion, replacing a dead CPU chip, dead oscillator, dead bass section, no output, broken phase shifter, and the list goes on.

This ARP Quadra is now for sale below.

Restored Vintage ARP Quadra Synthesizer Keyboard

I bought several broken ARP Odysseys, and as is common with the Black & Gold ARPs, a number of them had heavy wear to the gold lettering on the panel. After meticulously restoring the electronics of this one, I decided to risk it all to see if I could successfully re-silkscreen the panel graphics myself. The result wasn’t impressive. Though it made usable again a synth that was otherwise unusable since you didn’t know what slider did what.

Vintage ARP Odyssey Mk II 2813 w/Moog Ladder Filter Fully Serviced w/ LED Sliders

I have 2 recently refurbished ARP Odysseys side by side. They’re identical model 2800’s except one has the original 4023 voltage controlled filter and the other has my clone of the 4023. Which one do you think is the original??

While restoring this ARP Axxe I found that the voltage controlled filter wasn’t working right–it wasn’t filtering anything! In this video we put the filter into my ARP Filter test fixture and track down the problem using the schematics.

In the last part of this series, we repaired the power supply & recapped this lovely Rhodes Chroma. Today I show you some of the upgrades I made to the Rhodes Chroma, and we have a listen to some of the many sounds the Chroma is capable of.

My usual disclaimer: none of the sample sounds played are intended to be musical, I am not demonstrating my musical ability (or total lack thereof), just showing some of the sounds the Chroma can make.

In the last video we figured out why this Rhodes Chroma wouldn’t work. In this video, we make the repair to the power supply as well as recap the synth and clean up some corrosion on the CPU board.

Viewer submissions for new time-lapse soldering music is welcome!

Before this Omni gets shipped off to the UK, I explain the mains wiring and show how to convert an ARP from 120V to 240V operation.

You will learn why the lamp on the power switch is meaningless as a diagnostic indicator, as well as where there is a dangerous wire that is color coded neutral but is actually hot mains level.

I briefly show you my set up to test ARP Voltage Controlled Filter submodules. We also have a listen to a couple of different ARP filter designs, the 4075 found in all ARPs from 1975 on, and the 4035 Moog style ladder filter found in some rarer Odysseys.

This Rhodes Chroma lay dormant for over a decade, and wouldn’t wake up from its long nap. In this video we troubleshoot and repair the power supply and get the synth alive and making sound. We also have a brief tour around the inside of this legendary polysynth.

Want to see more of the restoration and upgrade of this Chroma? Let me know what you’d like to see in the comments!

Introducing an innovative replacement for the obsolete and impossible to find ARP Octave Transpose switch found on the ARP Pro Soloist & Pro/DGX. Let me know in the comments what you think of this as a replacement! If there’s any interest, I will also make one for other ARP synths like the Odyssey and Axxe.

This particular Pro Soloist also has my replacement 4034 filter submodule installed, which sounds just like the original, only better!

Synthchaser LED Octave Transpose Switch for ARP Pro Soloist & Pro/DGX Synthesizers

Synthchaser ARP 4034 VCF Filter Submodule