Hi! Some news about the amplifier :
I have greatly improve the THD... by disconnecting the multimeter who was tracking the bias on the emitters resistors... I should have think about it before.
I have made some measurments of how the resistor on the base of the transistor CCS voltage reference influ THD. I have use 1k. With the reference connected to the VAS CCS, the THD without it is 0.08%, with the resistor it is 0.008%, 10 time improvement! :tu:
With the reference connected to LTP CCS, the THD without it is 0.1%, and with it, again 0.008%. I think the major distortion now come from elsewhere in the circuit, so the difference in the transistor position is not measurable.
I have not improve the thermal tracking for now, so the results are approximate.
I have greatly improve the THD... by disconnecting the multimeter who was tracking the bias on the emitters resistors... I should have think about it before.
I have made some measurments of how the resistor on the base of the transistor CCS voltage reference influ THD. I have use 1k. With the reference connected to the VAS CCS, the THD without it is 0.08%, with the resistor it is 0.008%, 10 time improvement! :tu:
With the reference connected to LTP CCS, the THD without it is 0.1%, and with it, again 0.008%. I think the major distortion now come from elsewhere in the circuit, so the difference in the transistor position is not measurable.
I have not improve the thermal tracking for now, so the results are approximate.