Author: synthchaser

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Synthchaser MIDI Adapter for ARP Quadra – Synthchaser #152

Supply chain issues are finally easing up and I’m able to produce another run of the MIDI Adapter I designed for the ARP Quadra back in 2021. It is the first and only MIDI interface for the ARP Quadra synthesizer! This MIDI adapter is user installable and requires no soldering or permanent modifications to the synthesizer to install (other than perhaps holes to mount MIDI jacks). Simply replaces the existing keyboard electronics board. Provides MIDI In, Out and Through capabilities! Supports aftertouch In and Out (via MIDI In, aftertouch will be applied to the full 5 octaves of lead synth instead of just the upper 3 octaves as limited by the original hardware). Supports duophony in the lead synth section and is compatible with the Quadra’s internal sequencer/arpeggiator.

In this video I show how easy it is to install, and how it allows you to interface with all 4 sections of the Quadra.

Synthchaser MIDI Adapter for ARP Quadra

 

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Oberheim Four Voice Synthesizer FVS Tour Inside & Technical Overview – Synthchaser #148

https://youtu.be/sMaqV7fHyTg

I’m going to be doing some repairs on this Oberheim Four Voice synthesizer and I thought I’d make a repair video on it. But first I want to provide some better context for the repair work that’s to come. So in this video we’ll look at the inside of the Four Voice, see the different modules that make it up and discuss how they work together to make an amazing synthesizer.

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Korg MS2000R / MS2000 DSP Troubleshooting & Repair – Synthchaser #146

New synths seem designed to be disposable, or repairable by replacing a whole board, which often costs more than the synth is worth. Today we do board level troubleshooting and repair on this Korg MS2000R that had no output and gave a “MPUtoDSP check error”.

00:00 Intro & where I’ve been the last few months
02:48 The problem & troubleshooting plan and setup
06:08 Oscilloscope probing
12:27 Removing the old DSP chip
14:33 Soldering the new DSP chip
16:15 Test and head off for a cold drink

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Oberheim OB-X and OB-Xa Memory Protect Switch

Recently got a question from someone unable to save patches on his OB-Xa.  “Where is the memory protect switch located?”.  On the OB-X and OB-Xa, the memory protect switch is located on the main processor board inside the case.  To access the switch, you will need to unscrew two screws on the left and right of the synthesizer to lift the front panel and access the board.   The switch is located as indicated in the pictures below.  On the OB-8, someone finally got a clue and moved the switch to the back panel where it can be accessed without opening the synthesizer.