Only for your information I don't use C10, ok I will do the changes & rapport, thank you Nick.
As you use (6k8r // 1M) = 6754r
6754 x .047 = 317.44 almost = 318, I would say you are spot on the 500.5Hz mid point.
It should sound very good as is.
Let us know your oppinion if you reduce the 15,2n to 15n
6754 x .047 = 317.44 almost = 318, I would say you are spot on the 500.5Hz mid point.
It should sound very good as is.
Let us know your oppinion if you reduce the 15,2n to 15n
After jump R9 & take off C5 I measured again the voltages:
Left channel
Leds to gnd 7.30V
Across R17 0.259V
R10/Q2 to gnd 10.30V
R1/Q3 to gnd 11.32V
R7 to gnd 10.51V
Drain Q5 to gnd 19.85V
Right channel
Leds to gnd 7.50V
Across R17 0.285V
R10/Q2 to gnd 11.24V
R1/Q3 to gnd 11.80V
R7 to gnd 11.30V
Drain Q5 to gnd 18.80V
It's necessary to adjust R10/Q2 to gnd at 10.0V with R6 trimmer & do the measurements again?
Better match channels there with R6 trimmer, yes. Also in right channel I see a bit high through R7. Its because voltage Q2 is high, but make your R7s 1.2k if you have.
Left channel
Leds to gnd 7.29V
Across R17 0.261V
R10/Q2 to gnd 9.02V
R1/Q3 to gnd 11.69V
R7 to gnd 10.00V
Drain Q5 to gnd 21.3V
Right channel
Leds to gnd 7.55V
Across R17 0.286V
R10/Q2 to gnd 9.86V
R1/Q3 to gnd 12.00V
R7 to gnd 10.00V
Drain Q5 to gnd 26.3V
Leds to gnd 7.29V
Across R17 0.261V
R10/Q2 to gnd 9.02V
R1/Q3 to gnd 11.69V
R7 to gnd 10.00V
Drain Q5 to gnd 21.3V
Right channel
Leds to gnd 7.55V
Across R17 0.286V
R10/Q2 to gnd 9.86V
R1/Q3 to gnd 12.00V
R7 to gnd 10.00V
Drain Q5 to gnd 26.3V
Don't trim to match at R7, trim to match at R10/Q2 to GND. 10-11V. Current is better for your IDSS through R7 now.
The only point of interest for alike gain between channels in 2nd stage is R10/Q2 to GND. The other voltages in buffer derive from drops due to static bias differences between channels and different -Vp. They just need to be logical.
OK, so now the current is under IDSS in the buffer also. Make R11 3K3 0.5W to go lower Q5 to GND and avoid some dissipation on the buffer FETS.