Hi,
I am interested to tweak DoZ Pre Amp (ESP Red Elliots), originally at:
Minimalist Discrete Hi-Fi Preamp
or
Minimalist Discrete Hi-Fi Preamp
1. Can I swap BJT of Q3 to N JFET like 2sk170, as there is a voltage adjustment (trimpot) that - I think - should work to adjust working bias of JFET also?
2. And what about Q2 (with 2sj complement), as it is also common to have FET there (as the BJT-Q4 as voltage/current sense will auto adjust the voltage needed).
3. And what about Q1, just modifying R3, to route it to the source (junction of R6 and R5) instead of to GND?
4. Why in the 37a, voltage/bias adjustment is "injected" to emitor/source, instead of at 37, "injected" to grid/basis? Both will work theoritically (and I do have experiement both). What is the difference, sound quality/character/sonic/noise etc?
Thanks,
Ervin L
I am interested to tweak DoZ Pre Amp (ESP Red Elliots), originally at:
Minimalist Discrete Hi-Fi Preamp
or
Minimalist Discrete Hi-Fi Preamp
1. Can I swap BJT of Q3 to N JFET like 2sk170, as there is a voltage adjustment (trimpot) that - I think - should work to adjust working bias of JFET also?
2. And what about Q2 (with 2sj complement), as it is also common to have FET there (as the BJT-Q4 as voltage/current sense will auto adjust the voltage needed).
3. And what about Q1, just modifying R3, to route it to the source (junction of R6 and R5) instead of to GND?
4. Why in the 37a, voltage/bias adjustment is "injected" to emitor/source, instead of at 37, "injected" to grid/basis? Both will work theoritically (and I do have experiement both). What is the difference, sound quality/character/sonic/noise etc?
Thanks,
Ervin L