500W PA amplifier with Limiter

[viki_v2]

Originally Posted by AndrewT

I think you mean 33E = 33r = 33ohm resistor.
If that is the case, then E33=0r33 = zero point three three ohm resistor.

Do not drop the leading zero. It is important to accurate transfer of information.

O O I messed up, will change to or33 and post

[AndrewT]

0r33 not or33
Zero point three three.
That Zero is important. do not call it o nor O get used to Zero, that is quite different.

Notice I did not say Zero point thirty three. never join the digits after the decimal point. Always read them out separately. Only the digits before the decimal point are allowed to joined. 124 becomes one hundred and twenty four, but 0.33 never becomes: point thirty three.

[viki_v2]

Originally Posted by viki_v2

O O I messed up, will change to or33 and post

i changed the resistors to 0.33 still no sound. no activity at out.

[mj777]

Sir Apex, I have a problem with this B500, as soon as I switch on the circuit, the 100R resistor (R20,R21) is getting burned:
this are the specs of the circuit taken from the forum and schematics:
psu: +/- 68Vdc
transistors: 1943&5200, mje340/350,2n5401,2n5551, zeners 15Volts 1 watt, R24/25 2.2K 2watts. I attached some pictures for everyone to give me some advice, tanx in advance for any help u can give.nsl32 replace by red LED and 47K resistor.

Regards,
mj777

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[andrewlebon]

hi mj777
greetings i had the same problem CHECK PIN COONNECTIONS OF
2N5401 2N5551 lots of fake transistors around same make BASE PIN was at side
not middle in some base pin was in centre both transistors had these 2n5401 2n5551 HOPE this helps you out
thanking you
andrew lebon

[mj777]

thanks andrewlebon i will try to check those transistors.

regards,
mj777

[andrewlebon]

hi mjm777
greetings why you dont use ldr and led combination instead of nsl32
easy and cheap to make
thanking you
andrew lebon

[viki_v2]

Originally Posted by AndrewT

0r33 not or33
Zero point three three.
That Zero is important. do not call it o nor O get used to Zero, that is quite different.

Notice I did not say Zero point thirty three. never join the digits after the decimal point. Always read them out separately. Only the digits before the decimal point are allowed to joined. 124 becomes one hundred and twenty four, but 0.33 never becomes: point thirty three.

Sorry but if it isnt zero. thirty three, what will it be.
i purchased . thirty three ohm resistor for b500.
please guide.

[mj777]

dear andrewlebon,
i have tried to check the transistors and all seems to be working fine, to verify that it is working(the transistors) I fixed it on my other diy amp the dx blame mk2 prototype and it is working fine. so i think the problem is not in the transistors, any other ideas u can share? and in ur nsl 32 replacement what is the resistance value of the ldr u use?
regards,

mj777

[jalou1995]

Originally Posted by mj777

dear andrewlebon,
i have tried to check the transistors and all seems to be working fine, to verify that it is working(the transistors) I fixed it on my other diy amp the dx blame mk2 prototype and it is working fine. so i think the problem is not in the transistors, any other ideas u can share? and in ur nsl 32 replacement what is the resistance value of the ldr u use?
regards,

mj777

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500W PA amplifier with Limiter

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