Encouraged, i added the output stage. Well, good news, bad news. Good first, it works. Bad news, i draws too much current. Vr4 is at min, and still too much current.
How do i lower it?
How do i lower it?
Correction...i meant vr1 has very 'little' effect...i dropped the word 'little'.
Good news, i found mistake, swapped accidentaly drain and source. Now it drawes correct amps. Sounds great, actually.
Still in testing mode, getting to know the interplay betweet trimmers.
Good news, i found mistake, swapped accidentaly drain and source. Now it drawes correct amps. Sounds great, actually.
Still in testing mode, getting to know the interplay betweet trimmers.
If the output comes from the drain (and the input into the gate) it is common source. The “common” terminal is always the one at AC ground.
vr1 is setting the jfets current, correct current for low distortion, vr2 may be the feeback control (gain and distortion control).
Yes, vr1 sets the jfet current, but it affects dc on output as well
But no matter what position, adjusting remaining trimmers accordingly it has very little effect on sound
Vr2 however, controls distortion, and messes up dc balance, it has to be adjusted carefully as it has profound effect. You can go from great sound to distorted in a blink of an eye
Vr3 is master dc control and works great
In their later scheme with servo, they used smaller value trimmer flanked by bigger resistors, to allow for finer adjustment
Right now its little touchy
Vr4 sets current
This is nice sounding amp, i am still using it withjust a test speakers, but i decided to finish it to the box with final power supply. Right now its powered using test power supplies through variac
One thing i changed, that grounded output. It presented no advantage in my case
Cheers
But no matter what position, adjusting remaining trimmers accordingly it has very little effect on sound
Vr2 however, controls distortion, and messes up dc balance, it has to be adjusted carefully as it has profound effect. You can go from great sound to distorted in a blink of an eye
Vr3 is master dc control and works great
In their later scheme with servo, they used smaller value trimmer flanked by bigger resistors, to allow for finer adjustment
Right now its little touchy
Vr4 sets current
This is nice sounding amp, i am still using it withjust a test speakers, but i decided to finish it to the box with final power supply. Right now its powered using test power supplies through variac
One thing i changed, that grounded output. It presented no advantage in my case
Cheers
Lot more amplifiers with the same outputs.
Does anyone has stock?
2SJ200/2SK1529pp 2stage power amplifier
Does anyone has stock?
2SJ200/2SK1529pp 2stage power amplifier