non inverting vs inverting 3875

[sangram]

Originally posted by Kuei Yang Wang
...I think you may wish to repeat the comparison using the latest inverting schematic, with 10k/22k/220k resistors around the negative input and 18k to ground on the positive input.

OK, I'll try 220K but last I remember anything above 100K was creating too much noise. I'll try it out anyway.

Also the source may be not as loaded as there is a volume pot before the input cap. I rarely push it above 50% mark, so I assume the source is looking into an impedance ~50K or so at 50%. Not a problem as such.

I forgot to mention. I am using a 18K resistor to ground in the TDA 2030. The STK with the calculated value was giving offset ~1V. It needs the value to be equal to the feedback resistor, to ground the + input. I will try a few more values and report back.