Mile
Try to put square wave threw the amp with 8R load to check if is not oscillating, I had some problem to get it stable with square wave (i putted 2n--10R compensation at front stage). Mje340 in biasing (I know is only for symulation here) - I have some bad experiance (or I am doing something wrong), looks like they have bad hfe at high temeratures - I left my amp with 100mA bias on and after 40min radiator had 165 Celcius with bias 2,5A. Maybe 2sc3964 ??
Try to put square wave threw the amp with 8R load to check if is not oscillating, I had some problem to get it stable with square wave (i putted 2n--10R compensation at front stage). Mje340 in biasing (I know is only for symulation here) - I have some bad experiance (or I am doing something wrong), looks like they have bad hfe at high temeratures - I left my amp with 100mA bias on and after 40min radiator had 165 Celcius with bias 2,5A. Maybe 2sc3964 ??
The feedback resistor r24 has to dissipate 350mW at Max power. This would be to high for me. When using high quality rnd55 resistors, I try to stay below 100mW dissipation.
What do you think about this? Am I to conservative?
22k for R24 and 10pF for C5 can be use instead values on test schematic for simulation.
I putted back bd139 and amp is playing past few days no problem.
I just wanted to try mje340, so I learned a lesson.
THX
I just wanted to try mje340, so I learned a lesson.
THX
No it was BG1 amplifier with 3 pair of outputs. The diamond amp is stable ok, biasing bd139.
Funny think is that changing slightly current in first or second pair is changing harmonics spectrum and little bit sound too.
Tomorow I will try to make a prototype of your amp (I hope I will have enough time).
Funny think is that changing slightly current in first or second pair is changing harmonics spectrum and little bit sound too.
Tomorow I will try to make a prototype of your amp (I hope I will have enough time).
Diamond buffer have adventage compare to simple symmetrical input, I use it in AX17
Attachments
Mile,
That is a very nice layout. Is it published somewhere for self-etching? I've looked for it in 100W Ultimate Fidelity Amplifier thread and couldn't find it.
That is a very nice layout. Is it published somewhere for self-etching? I've looked for it in 100W Ultimate Fidelity Amplifier thread and couldn't find it.
Sansui s diamond circuit is a fet single differential that drive
a symmetrical differential , see below.
Attachments
Layout is from Romanian forum Forumul electronistilor • Vezi subiect - Amplificator APEX 100W - Putere si Fidelitate
Thank you for the link. I've registered on this forum but I couldn't find the layout anyway. Oh well, looks like I'll have to draw my own 🙂)
Several AX17 pcb designs with single pair is available http://www.diyaudio.com/forums/solid-state/164093-100w-ultimate-fidelity-amplifier-281.html
