500W PA amplifier with Limiter

thank you for warning kandimba, i have only this for power. its coming from old amp. 62vdc was feeding 2 channel, and 88v dc for subb channel. maybe i can use that 44-0-44. still cannot find any 2w zener that is big problem here in turkey. i search all sellers and no one have it. i will build other parts and wait for zeners.
 

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thank you for warning kandimba, i have only this for power. its coming from old amp. 62vdc was feeding 2 channel, and 88v dc for subb channel. maybe i can use that 44-0-44. still cannot find any 2w zener that is big problem here in turkey. i search all sellers and no one have it. i will build other parts and wait for zeners.

What a WEIRD transformer.

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What is the current capacity for each winding?
I simply can not believe you can extract full transformer power from any of them at random.
I´d expect *one* beefy winding and the others being lower rated.
What exact amplifier (brand and model) did it come from?

What does the "350" in the model name mean? 350VA? 3500VA?
Do you have a direct link to manufacturer? Any datasheet?
As of the Zeners, if Apex told you 1W is fine, so be it :)

But if it were not, you can´t parallel Zeners for power sharing but you can use them in series, so proper full spec replacement should have been 2 x 7.5V 1W Zeners in series.
 
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What a WEIRD transformer.

What is the current capacity for each winding?
I simply can not believe you can extract full transformer power from any of them at random.
I´d expect *one* beefy winding and the others being lower rated.
What exact amplifier (brand and model) did it come from?

What does the "350" in the model name mean? 350VA? 3500VA?
Do you have a direct link to manufacturer? Any datasheet?
As of the Zeners, if Apex told you 1W is fine, so be it :)

But if it were not, you can´t parallel Zeners for power sharing but you can use them in series, so proper full spec replacement should have been 2 x 7.5V 1W Zeners in series.

hi, its coming from reborn amplifier. 2 channel each 350w and 1 channel subb 300w. i have that amplifier schematic too i can add if you want. that 350 coming from schematic name hi-350.

abouth zener apex said i can use 1w. but if i use series i need use2x 1w 7.5v zener? sory for my english and thank you for answers. and feel good learning some thing else...
 
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finally

hi friends,

finally i start for b500. one of my sellers call me and said he have 2w zener 15v. they dont know what they have in their stock. i want to ask i need to make 2 protect for 2 channel? or there is any way modify protect board for 2 channels.

thank you for answers...
 

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cables

hi friends.

i make b500 finaly. but there is some things i cant understand.

when i connect input ground to input ground, volume not coming enough. if i connect it to output ground volume getting x2

there is input, gnd, A, B, on connector. what should i connect to A and B i think i doing some thing wrong.

note: i dont have loud speaker in home so i testing with 4 ohm 10w small speaker.
 

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i dont understand what is the problem i am getting sick abouth it. yesterday it was working. to day its not working

giving me 13v dc at output. and when i check the voltage i see +11v and -65. then i disconnect power and check on powersuply. its normal +- 65v dc. but when i connect b500 positive side drop to 11v.

1- i check zener its good.

2- i check all roads no short.

3- i check diodes and 5200, 1943 all is ok.

4. on the R23 330R connected at mje340 emiter to base 0volt on it.

i dont know what else to check

please some one help me
 
If you measure +/-63v on capacitor bank and the same time on the amplifier board you measure 11v it is one and only one fault ,the connection cable and the connection terminals.

i dont know how i dont see the cable broken inside ty my friend but now i have another problem. i change 5551 and 5401 cause i read some one get problem for them. and now R20 100r frying 2 times i check all roads there is no short i am sure. maybe that mje340 have problem but i dont have another one for test. but i take it out and check with multimeter and it look like ok.:confused::confused::confused:
 

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i dont know how i dont see the cable broken inside ty my friend but now i have another problem. i change 5551 and 5401 cause i read some one get problem for them. and now R20 100r frying 2 times i check all roads there is no short i am sure. maybe that mje340 have problem but i dont have another one for test. but i take it out and check with multimeter and it look like ok.:confused::confused::confused:
What are you using instead of 5551 and 5401?
 
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