ACD said:If you want to drive 4 Ohm speakers it would be a very good idea to add at least one extra set of output transistors
Yes but I can't mount others output transistors.
I want to make make a little optimization to make a little more stable the output and drivers stage.
What do you think about a 100nF capacitor on E - C of Q1
and a 39pF capacatitors on B - C of Q2 and Q3 ?
"What do you think about a 100nF capacitor on E - C of Q1 "
I would do 1µF across R7, R8 instead.
I would also use a better opamp, not too fast. A NE5534 with the correct cap would sound much better.
Bypass C4, 5, 7 with 100nF.
I would rather see R10, 11 fed from the stabilized opamp supplies. The values would need to be lowered to keep the current up.
I did a commercial design of a CFP output stage with gain, driven from an opamp, about 10 years ago. It sounded quite good.
I would do 1µF across R7, R8 instead.
I would also use a better opamp, not too fast. A NE5534 with the correct cap would sound much better.
Bypass C4, 5, 7 with 100nF.
I would rather see R10, 11 fed from the stabilized opamp supplies. The values would need to be lowered to keep the current up.
I did a commercial design of a CFP output stage with gain, driven from an opamp, about 10 years ago. It sounded quite good.
Why don't you check out Jan's amp? The same idea but a little bit developed.
http://www.delta-audio.com/PA-34A.htm
http://www.delta-audio.com/PA-34A.htm
Here is my amp design with OPA frontend. Cheap, simple, but powerful and sounds nice.
schema: http://edl.uw.hu/sch.jpg
parts list: http://edl.uw.hu/parts.jpg
schema: http://edl.uw.hu/sch.jpg
parts list: http://edl.uw.hu/parts.jpg
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.