12 May
2016
12 May
'16
9:16 a.m.
Hi all, I have done a test on a different Pyra board:
* there I have no stereo (i.e. one channel is dead) * no scratch and noise bursts - so that might be a completely unrelated issue of the test board I have used first * the clipping is still present at higher volume - this indeed sounds like mechanical noise from the speakers running into the stop block... If I mentally try to ignore this sound component the music sounds good and crisp and high quality.
Summary: some of the problems are related to the specific unit I have tested so far (the whole OMAP5 runs a little less stable - maybe our 19MHz XTAL is instable?). Another problem is with the D-class amplifier making the speaker membrane run into full deflection.
BR, Nikolaus