#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:

highgain

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

Lets take the device apart:

DSC00005DSC00006

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

DSC00007

A quick look around and touching cables reveals the problem:

DSC00011

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

DSC00012

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

 

DSC00013

both channels work now 🙂 success.

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One response to “#oggstreamer – Repair Series 1 – channel not working / high gain

  1. Hi
    You could exchange the position of the potentiometer P1:1 and the resistor R8 in the circuit. So if the connector gets loose or if the slider of P1 is lifting then the gain gets zero instead of infinity.

    Of course the connection of the potentiometer itself has to be changed also in order to turn louder when turning to knob to the right.

    Maybe a task for the next revision… 😉

    regards, Fritz

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