Monthly Archives: November 2014

#oggstreamer – Repair Series 1 – channel not working / high gain

some weeks ago I had to exchange an OggStreamer because one channel was not working – the user Mike recorded the following video to demonstrate the problem:

If you watch the video closely you can see that the left channel is always amplifying the Audio with a very high gain – and only as he turns the gain up also the right channel appears – actually it is the right channel that is working correctly and the left has an error where it has a very high gain.

Looking at the schematics reveals that a connection error to the Potentiometer (which is in the Feedback loop) could cause such a high gain of the inverting amplifier:

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So a loose connector is my first guess. My second guess would be a faulty potentiometer.

Lets take the device apart:

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gently push the whole assembly (top and pcb) out of the extruded alluminium case:

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A quick look around and touching cables reveals the problem:

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because I had a spare contact lying around i soldered on a new contact, but elsewise I could have recycled the orignial one:

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Time to put everything to gether and check if it works:

 

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both channels work now 🙂 success.

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