ProtoDAC TDA1387 X8 project

[hifinet]

@thomaschan The BF245B circuit with the 820 ohm source resistor is biased for a TDA1541A. The TDA1387 X8 will have a different bias point. I think the TDA1541 sinks about 4mA current at idle. The TDA1387 X8 produces about 4.5mA current at idle (based on 1.9V/420 ohm I/V resistor). After the 1541, the voltage on the gate with 100 ohm I/V is -0.4V. With the 1387 it is +0.45V (you can confirm and measure this voltage at the gate with a DMM). With the 820 ohm source resistor, I think the BF245B is under biased. To achieve the same bias point as the 1541, the value of the source resistor should be increased to 1000 ohms. You could try it and see if it sounds better.