Part Number:PCM1792A
Hello again!
I was looking at the datasheet for the PCM1792 again (fig.37) and had another idea that might reduce distortion at higher audio frequencies (i.e. >10kHz).
As before, I am thinking that the op-amps should use around 2k2 as feedback resistors instead of below 1k. This would give an optimal balance between noise and distortion in the OPAx134. The problem is the first op-amp that converts the output current of the PCM1792 to voltage (U1 and U2). It would be difficult to use a resistor with much more than the proposed 820R due to the centre current (-6,2mA).
One way to solve the matter would be to connect a resistor between the 5V (quiet) VCC supply line and the output of the PCM1792. Setting the resistor close to 806R would effectively reduce the output centre current from -6,2mA to zero. Then I can use whatever feedback resistor I want in (U1 and U2).
Is it ok to do this or would it introduce other problems?
Thanks
Mark