Re: uBitx has a bit too crispy / semi-distorted audio even on low signal levels #ubitx #ubitx-help

 

Mike,

Try this: Lift up D15 or 16 diconnecting one end from the board. Solder the
center and one end of a 47 ot 100 Ohm preset between the two diodes.
Make sure the preset is at minimum. Power up and slowly increase the
preset till distortion goes away.See that the Q72/73 don't get hot while
the volume is low.

You are increasing the quiescent current in the final transistor to overcome
cross over distortion.
https://en.wikipedia.org/wiki/Crossover_distortion


Raj


At 16/06/2018, you wrote:
Raj, VU2ZAP: here are the voltages you asked for.
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