Diy preamp for Amplifier IRFP240/IRFP9240

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Yes, one channel is shown on the schematic. You can use the same PSU if supply voltage is correct.



... Stereo Schematic ... something is missing ?

doc110.jpg
 
Valery, will this buffer be good enough to drive headphones?
MJE3xx should be enough.

Yes, but in this case it needs some "power-up":

R1, R2 = 220R
R7, R8 = 4R7
R6 = 10R

MJE3xx need some small local heatsinks.
Power supply should be capable of giving at least 50mA (for 2 channels).
It is also recommended to use some simple output protection in case of DC coupling - if something goes wrong, DC at the output will likely kill the phones 😉
 
No reference to GND at input and output thus risks for plops when connecting cables. No protection against cable capacitance, No HF/RF input filtering. No DC blocking at either input or output. No muting relay so burned "woofer syndrome" when wrong power on sequence is done.

Not suitable for generic use.
 
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