Its not about that, some component value like capacitors and resistors are there for a reason of +/-40vdc. build a working AX11 firts before of thingking modifiying the circuit.
Good. Is it necessary to heat sink the drivers (BD139/40)? What about thermal touch sensation?
Regards.
ok,i will test it on a +/-25v supply ,and then make modifications,and then wind a higher voltage transformer
Nice work and this is the first AX11 made by forum member, I'm sure there will be many others in the future.
Regards
Hi, PetruV.
If you want more power, just build B500,A100,F100. All 3 are cheap and good power amps.
AX11 is Hi-fi home amplifier project, with one pair output transistors, like in commercial amps.
If you want more power, just build B500,A100,F100. All 3 are cheap and good power amps.
AX11 is Hi-fi home amplifier project, with one pair output transistors, like in commercial amps.
Hi,
BD139/140 are warm but not to mutch. You can touch them without any problem. But BC639/640 are very hot. The amplifier runs with +-38V DC. And I have not tested yet with power.
regards Olaf
If I find the time, I will try the PCB with BD139/149 and BC 639/640 on the same heatsink. It's a very elegant solution.
Maybe testing with another pair BD139/140 replacing BC639/640. Same characteristics, better dissipation (to-126 x to-92).
Any recommendation from Apex?
Regards.
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BF471/472, BF871/872... many pairs can be use in this design, also CCS current and heat on VAS transistors can be reduce: just use 220R instead 180R in CCS. Gain can be increase: use 680R instead 2k2 in feedback... this amp is for fan.
I've played a bit. A small heatsink connected with thermal adhesive (more for peace of mind;-). Some photos for 20kHz, 10kHz and 1 kHz with signal generator until 30V peak to peak at output. Load resistance and heatsink are good warm (too small).
In each perspective the amplifier operates stable and has a warm and transparent sound.
It is a very nice, cool amplifier - typical apex.
It's fun to build it and you get an impressive sound.
Thanks again to Apex.
regards
In each perspective the amplifier operates stable and has a warm and transparent sound.
It is a very nice, cool amplifier - typical apex.
It's fun to build it and you get an impressive sound.
Thanks again to Apex.
regards
Attachments
APEX AX11 PSU in Progress....
Let me know if anyone found mistake....
Just for fun..😉
Regards,
Let me know if anyone found mistake....
Just for fun..😉
Regards,
Attachments
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Hi Alex,
Good to see u around... actually its not finish that's why It's non labeled and can be change for something preferable one...
Regards,
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