500W PA amplifier with Limiter

[toreto009]

all of you solders is good? And check the input capacitor too.
To my old amp that problem it was from input capacitor, was leaking.

soldered all is well, replace the capacitor?

 

[apexaudio]

Hello everybody! I did B500, it works, but it does not play cleanly in a small volume. But with an increase in volume plays perfectly. What to check?

Amp is underbiased, replace 680R in bias circuit with 1k pot and set bias to 30mA

 

[toreto009]

Amp is underbiased, replace 680R in bias circuit with 1k pot and set bias to 30mA

This 680R?

 

[apexaudio]

This 680R?

yes

 

[toreto009]

yes

I can leave the LED and resistor in place of NSL 32? Or remove it?

 

[apexaudio]

I can leave the LED and resistor in place of NSL 32? Or remove it?

can leave

 

[toreto009]

can leave

but it is better with a resistor or without 47K?

 

[ArDean]

can leave

resiistor rating for b500 beside re nad r shunt
any sugestion using of rating 0.25w 0r 0.5 watt?
wich is better? thanks

 

[selvakumargoi]

B500 TEF WITH PROTECTOR SPEAKER

PLEASE ARRANGE TO SHARE PASSWORD
YOUR PASSWORD IS VERY VERY URGENT FOR ME

MY E-MAIL ID :JAGANEESH2010@GMAIL.COM

 

[france]

hi sir apex,

can i ask a help my b500 after my friend borrow & return to me the sounds now is distorted no bass i think more on mid an the out has -12mv already what should i need to replace. before he borrow the amp the sounds is so clear & bass, mid , hi is balance what happen to my amp.

 

[france]

i fixed already just a hair line problem on pcb ground.

 

[chico67]

Hi guys.
I've made B500 and it has 50mV output DC offset that seems OK, but input has 375mV DC too.
what is the root of this problem, how to fix this issue?

best regards.

 

[france]

Hi guys.
I've made B500 and it has 50mV output DC offset that seems OK, but input has 375mV DC too.
what is the root of this problem, how to fix this issue?

best regards.

check proper grounding same problem i encounter.

 

[moore4889]

Hi guys.
I've made B500 and it has 50mV output DC offset that seems OK, but input has 375mV DC too.
what is the root of this problem, how to fix this issue?

best regards.

Please check,, input ground should be connected to power supply ground...

 

[chico67]

Thanks for your help.
I've checked it, there is no conection between power supply GND and input GND.
I've also checked schematic, i couldn't find any conection between them.
it seems that input GND and power supply GND aren't same.

Thanks.

 

[apexaudio]

Thanks for your help.
I've checked it, there is no conection between power supply GND and input GND.
I've also checked schematic, i couldn't find any conection between them.
it seems that input GND and power supply GND aren't same.

Thanks.

Connect input GND from input terminal to psu GND.
Regards

 

[apexaudio]

B500P

 

[chico67]

Connect input GND from input terminal to psu GND.
Regards

Thanks for your replay.
i connected input GND to PSU GND, but it still has -9mV dc at input.
i'm confusd😕

 

[chico67]

Connect input GND from input terminal to psu GND.
Regards

Thanks for your replay.
I connected input GND to PSU GND, but it still has -9mV dc at input.
i'm confused. 😕

 

[AndrewT]

how about showing that connection in the schematic?