In a lot of my videos, I use this little operational amplifier tester I built. By popular demand, I’ve decided to make a short run of them available. In this video I explain how my op amp tester works and how you can interpret its results to determine the mode of failure of many op-amp IC chips with standard pinouts.
Author: synthchaser
Sad ARP Quadra Repair & Restoration – Synthchaser #124
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.
Rhodes Suitcase Piano Pre-amplifier Repair & DIY Power Supply – Synthchaser #123
In this video we have a little look around and make a repair to a Rhodes Suitcase Mk I Electric piano. Since it was without the speaker cabinet, I built a standalone power supply to power the pre-amp and interface the piano to an external amp. However, the piano’s vibrato isn’t working, so we pull the pre-amp, repair the problem, and service the pre-amp to improve long term reliability.
Attempting to Re-Silkscreen a Vintage ARP Odyssey – Synthchaser #122
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.
Oxford Synthesizer Company OSCar Repair – Synthchaser #121
Have look inside and listen to a rare Oxford Synthesizer Company OSCar synth as we make a handful of repairs to it. We’ll convert it from 220V to 110V operation, change the power cord, correct the power wiring, clean the pots, replace the leaking battery with a safer solution, eliminate hum in the output, replace missing buttons, replace a sketchy connector, and fix some intermittent issue where the synth jumps back to preset #1.
ARP Odyssey 4023 Filter Original vs Clone Challenge – Synthchaser #120
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??
Synthchaser #119 – ARP Axxe Voltage Controlled Filter Repair
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.
Synthchaser #118 – Rhodes Chroma Repair & Restoration Part 3 – MIDI, Programmer & Demo Sounds
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.
Synthchaser #117 – Rhodes Chroma Repair & Restoration Part 2 – Power Supply & Recapping
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!
Synthchaser #116 – ARP Synthesizer Mains Power Wiring Explanation & 240V Conversion
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.
