MOSFET Amplifier IRFP240/IRFP9240

[apexaudio]

Thanks for the corrections.

U can also use this circuit, no need for cut-out circuit on PSU pcb.
Regards

 

[jash2008]

U can also use this circuit, no need for cut-out circuit on PSU pcb.
Regards

By the way, this might be a silly question:

You have designated some resistors as "FP" (example gate resistors) in your all drawings. Does it means something special?

 

[east electronics]

flame proof

 

[jash2008]

flame proof

Ok, thanks

 

[apexaudio]

By the way, this might be a silly question:

You have designated some resistors as "FP" (example gate resistors) in your all drawings. Does it means something special?

If U use circuit in post #161 one BC546 for bias must be on heatsink with outputs fets. Sakis already answer about FP.
Regards

 

[Valenca]

Hi apexaudio !

I can feed this amplifier with 90 + / 90 - volt DC? Works well?

 

[apexaudio]

Hi apexaudio !

I can feed this amplifier with 90 + / 90 - volt DC? Works well?

In post #1 U can find picture of this amplifier with 5 pairs mosfet which worked on +/-90V, but not for PA.
Regards

 

[Valenca]

OK, but is there any limitation for use in PA?

 

[apexaudio]

OK, but is there any limitation for use in PA?

No, but +/-75V is safty operation in PA

 

[khalsa]

Hi apex, I want ur pcb drawing with vi limiter of ur #161 circuit,
Thanks

 

[apexaudio]

Apex hv350

Hv350 sch+pcb

 

[apexaudio]

Hv350 pcb

 

[AndrewT]

Hi Apex,
could you point me to a description of the clip indicator operation?

 

[apexaudio]

With new bias circuit on HV350, bias current can be setup at higer value than HV23. Also with new VI limiter there is no need for cut-out protect on PSU and protect PCB.

 

[apexaudio]

Hi Apex,
could you point me to a description of the clip indicator operation?

When peak output voltage is <12V to rail voltage clip led light on.

 

[apexaudio]

Clip indicator

If no signal on the output of amplifier voltage on point 47k,22k,10R,10uF is 25V to the negative rail, BC546 is on and short circuit led diode, current go thru GND 10k1W CE of BC546 to negative rail. When voltage on output is about -65V (-75V rail voltage), voltage on point 47k,22k,10R,10uF is 10V to the negative rail, and in the point 22k,1k5,base BC546 is 0,6V to the negative rail, BC546 off current go thru GND 10k1W led to negative rail, and LED light. 10uF give some time delay for short peaks. Sorry for my English.
Regards Mile

 

[apexaudio]

I prefer stability in amplifier, who prefer value with 10pF instead 100pF amplifier have perfect square at 20kHz, but I do not recomended.

 

[khalsa]

hi apex kindly send me the pcb desin for #27 thanks

 

[apexaudio]

hi apex kindly send me the pcb desin for #27 thanks

If you post some pictures of your diy work, I will consider about that.
Regards

 

[engel dela pena]

apex,
do you have quasi design for fets
i have a bunch of 2sk's