DC Servo MOSFET Amplifier

[apexaudio]

F100 psu

On this PCB exept PSU is short-circuit and DC protect, clip indicator...

 

[apexaudio]

Short-circut even at low level cut-out speakers.

 

[apexaudio]

PCB size: 90x130mm

 

[apexaudio]

This PSU and Protect circuit ca be used with any amplifier. Short-circuit protect based on Tandberg schematics is 100% efficacy.

 

[apexaudio]

Ground for input amplifier must be conect with separate wire from PSU.

 

[maouna]

hi.can you provide schematics of this all-in -one pcb ?

 

[apexaudio]

hi.can you provide schematics of this all-in -one pcb ?

PSU and Protect?

 

[maouna]

yes.dc protect and clip indicator.

 

[apexaudio]

yes.dc protect and clip indicator.

Ok

 

[apexaudio]

yes.dc protect and clip indicator.

PSU+Protect Schematics

 

[maouna]

will it be ok if i use 24-0-24 transformer?will the clip indicator,short circuit protection and dc protect work correctly???

 

[apexaudio]

will it be ok if i use 24-0-24 transformer?will the clip indicator,short circuit protection and dc protect work correctly???

Yes, but some resistor value need to be changed.

 

[apexaudio]

I must say this is my most popular small PA amplifier in 90's. Over 400 pcbs in bars, restaurants, small clubs... still works.

 

[apexaudio]

F100 can work with TO220 fets IRF640/IRF9640 or IRF540/IRF9540 if rail voltage is +/-45Vmax.

 

[apexaudio]

I find this old pcb, same schematics with 5 pairs of mosfets, bias adjustment and protect on board, but files was lost.

 

[apexaudio]

After 15 years work...

 

[apexaudio]

I'm considering to remake this good old amps with some improvements...

 

[engel dela pena]

apex,
this design is +/-50 but i need replacement
bd139 MJE?
bf420 MPSA?
and i'd rather make 4 pairs of output
should i make .22r resistor .33 or .47?

 

[Globulator]

I'm not a big fan of solid state, but I have some questions!

I do not understand why you have C2 as well as C1.
What are the big 0.22R resistors for?
What is the loop feedback gain/amount?
What is the crossover distortion with the loop feedback removed?
I think you need a bias so you can also run in class AB (my opinion)
Why is there no bypass cap for the zener of the driver circuit?
Why is there no Zobel network (LC) on the output?

 

[apexaudio]

apex,
this design is +/-50 but i need replacement
bd139 MJE?
bf420 MPSA?
and i'd rather make 4 pairs of output
should i make .22r resistor .33 or .47?

If you want 4 pairs of output I sugest you to build this amp:
http://www.diyaudio.com/forums/solid-state/162043-mosfet-amplifier-irfp240-irfp9240-24.html
Regards