900W H-class PA Amp with Limiter

hi apexaudio

greetings
red wire 94 volts positive
brown wire 70 volts positive
green 0
blue wire 70 volts negative
black wire 94 volts negative
will send high resolution picture of pcb both rails supply drop to 16 volts approx
short suspected
thanking you
andrew lebon
 

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hi apexaudio

greetings
red wire 94 volts positive
brown wire 70 volts positive
green 0
blue wire 70 volts negative
black wire 94 volts negative
will send high resolution picture of pcb both rails supply drop to 16 volts approx
short suspected
thanking you
andrew lebon
Input GND missing! Amplifier can't work without connect input GND. I can't see wire jumper (red line on component layout) on botom side of pcb, somethimes I forget connect that wire.
Regards
 
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hi apexaudio

greetings thanks for your reply connection should be made to input gnd by seperate wire to pin next to input in is that correct

1 for pcb protect circuit for heat sensor transistor can mje340 be used instead of bd241

thanking you
andrew lebon
That's correct,
TIP31 can be used instead BD241, any NPN transistor can be used as thermal diode sensor but then reff voltage on comparators must be calibrate, becouse different 'Vbe on' for different transistor.
Regards
 
APEX
how about adding power trannies?let say 7 pairs
should .33R increase value
I don't want to diyers be afraid with "monster" amplifier useing six or seven pairs of output transistors, I use minimum on small pcb, you can add more outputs on larger pcb if you want. I see many amplifier with simple VAS simpler than my in "100w Ultimate Fidelity Amp" with seven pairs of outputs on large pcb called "monster" that's "fatamorgana" for my opinion.
Regards
 
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I don't want to diyers be afraid with "monster" amplifier useing six or seven pairs of output transistors, I use minimum on small pcb, you can add more outputs on larger pcb if you want. I see many amplifier with simple VAS simpler than my in "100w Ultimate Fidelity Amp" with seven pairs of outputs on large pcb called "monster" that's "fatamorgana" for my opinion.
Regards
what do you mean by fata morgana?
are you in favor or not to 7 pair output?
in this picture 2 pcb top & bottom share 1 heatsink?
 

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what do you mean by fata morgana?
are you in favor or not to 7 pair output?
in this picture 2 pcb top & bottom share 1 heatsink?
I mean, some amplifiers just look like "monster", and for a real are very simple, and not much powerfull as they designers say.
Yes I favor to use 7 pairs, but only on B500 and H900.
Amplifier on picture use 2 pcbs on 1 heatsink with 2 fans, work on 0,+/-55VDC,+/-110VDC, 2500w transformer. Heatsink is about 3kg, and amp can work on 2R load, but this is H1200 amplifier, not H900.
Regards
 
I mean, some amplifiers just look like "monster", and for a real are very simple, and not much powerfull as they designers say.
Yes I favor to use 7 pairs, but only on B500 and H900.
Amplifier on picture use 2 pcbs on 1 heatsink with 2 fans, work on 0,+/-55VDC,+/-110VDC, 2500w transformer. Heatsink is about 3kg, and amp can work on 2R load, but this is H1200 amplifier, not H900.
Regards
does your h1200 mean 1200w per module or 600w+600w
h900 450w+450w?
this means that those who knows amp math can upgrade h900 to
h1200?
 
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