MOSFET Amplifier IRFP240/IRFP9240

Hi the HV350 amp working for me with single pair of MOSFET and +/-33V. It's only for testing. I am going to construct the full function amplifier:)....

But the Toshiba transistors are not available in my nearest stores. for testing now i am using 2N5401&2N5551 instead of 2SA970&2SC2240. For other two complementary pairs i am using MJE340&MJE350 (sorry its only for testing). The amp works good but i want to match the perfect complementary pair for all the Toshiba transistors.

The transistor terminal changes not a problem, i will make the correction in my PCB design. My question is may i replace the 2SA970&2SC2240 pair with 2N5401&2N5551 permanently. What should be the equivalent transistors for other pairs and it should be easily available in market. Please give me a solution. Thank you.

Regards
Udhay
 
Hi the HV350 amp working for me with single pair of MOSFET and +/-33V. It's only for testing. I am going to construct the full function amplifier:)....

But the Toshiba transistors are not available in my nearest stores. for testing now i am using 2N5401&2N5551 instead of 2SA970&2SC2240. For other two complementary pairs i am using MJE340&MJE350 (sorry its only for testing). The amp works good but i want to match the perfect complementary pair for all the Toshiba transistors.

The transistor terminal changes not a problem, i will make the correction in my PCB design. My question is may i replace the 2SA970&2SC2240 pair with 2N5401&2N5551 permanently. What should be the equivalent transistors for other pairs and it should be easily available in market. Please give me a solution. Thank you.

Regards
Udhay
I try to use most available parts, and use design witch performance is independent of special parts. 2SA/2SC can be permanently replace with 2N, and you can replace other transistor, but try to maching hfe for simetry,
Regards
 
Thanks.
I need schematics because I don't know where to connect output,voltage,...
it's not marked on pcb.
Regards
This can help...
 

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Hv23 bias compensation

I dont use this PCB in a last 2 year (repleced with H class in PA and A class for home aplication), but I must build couple PCBs again and try to see the effect on some sugestion.
I set bias to 200mA, after 10min. amplifier was hot and bias decrease to 120mA. That's the fact for people who don't belive that HV23 have thermal stability. Thermal compensation with transistor in new version is need for do not underbiased not for overbiased amp.
Regards
 
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Look nice, but you must put driver transistors on heatsink with outputs, drivers work with 30mA bias and must be on heatsink. Better use some TO220 for drivers.
Regards

Yes thank you. But i already mention this is only for testing and now i am not using this amplifier. I am doing PCB work for final design,after that i will attach to heat sink and i didn't select an output transistor yet but i am thinking about MJE15032 & 33. What is your suggestion......

MJE15032 & 33 are not available in my city. It is only available in DIGIKEY. So may i use MJE350 & 340. It's get heat little more then output driver MOSFET(for +/-33 supply). Is it happen normally or anything wrong?