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Vintage Synth Repair

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Re: [vintagesynthrepair] Need some advice on fixing my OB-X

2013-05-29 by Rod Abernethy

Thanks Wes, I'll give this a shot and post the results.

-Rod



On May 26, 2013, at 2:17 PM, 65 Lotus <Lotus@...> wrote:


Here's something I ran across from Wes Taggart of Analogics. Worth a try...
=======================================================
Memory is a significant issue with the OB series of instruments (well any instrument with memory) in that it will do some pretty crazy things if the memory is bad or scrambled. Sometimes loading the memory is not enough. If problems still persist after loading the memory and replacing the battery, you may have to follow the procedure below:

Set unit to manual mode
pick patch A1
Turn every pot a couple times
Turn on and off every switch a couple of times.
This includes all the page 2 stuff also.
After the above, set a simple patch that you can easily identify. One oscillator, wide open filter, gate like envelope.
After you have the patch, write it to memory location A1.
Verify the patch is there by switching to another patch and then returning to A1.
Once verified, write this patch to every memory location. A real pain for those with 120 programs.
Load your program tape.

Scrambled memory creates issues because many times the value held in memory is outside the memory address range. So where the expected value is 0-255 and the actual value is -1,304,495. CPUs do not do well with this type of issue. Rotating the knobs allows the instrument to create a value within the expected value.

Wes Taggart
Analogics


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