Audison LRX5 600 No Sound

Frycztech

Member
2017-05-18 12:09 pm
I have a Audison amp that I just picked up and it turns on, the green power light comes on with no other lights. There is no sound coming from any of the channels. Any one can lend me a hand on where to start? It looks like the bottom of the amp got wet, there is some corrosion on the aluminum end caps. Here are some pictures of the board.
 

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I don't want to start an argument but alcohol isn't a good contact cleaner. You need something that will stay on the contacts, will lubricate and will carry away any contaminants.

That said, the problem is now likely in the muting circuit. I'm assuming that you've already confirmed that the amp is producing both positive and negative rail and regulated voltage.
 

Frycztech

Member
2017-05-18 12:09 pm
I don't want to start an argument but alcohol isn't a good contact cleaner. You need something that will stay on the contacts, will lubricate and will carry away any contaminants.

That said, the problem is now likely in the muting circuit. I'm assuming that you've already confirmed that the amp is producing both positive and negative rail and regulated voltage.


Perry,

I have voltage coming in and the power LED is lit. Are you referring the the rail voltage for the FET'S? Where is the muting circuit and how would I test that?
 
I don't have any information on this specific amp. I was hoping that someone who does have this information would give you specifics but no one has yet.

The rail voltage is the positive and negative on the output transistors.

The regulated voltage is the positive and negative voltage on the power supply pins of the op-amps in the preamp section.

The op-amps in the output section (near the bias pots) are likely used with switched voltage to serve as the muting circuit.

Measure the DC voltage across pins 4 and 8 of the 8-pin op-amps.
 

Frycztech

Member
2017-05-18 12:09 pm
I don't have any information on this specific amp. I was hoping that someone who does have this information would give you specifics but no one has yet.

The rail voltage is the positive and negative on the output transistors.

The regulated voltage is the positive and negative voltage on the power supply pins of the op-amps in the preamp section.

The op-amps in the output section (near the bias pots) are likely used with switched voltage to serve as the muting circuit.

Measure the DC voltage across pins 4 and 8 of the 8-pin op-amps.

Would the op-amps be the 2 LM324D'S?
 

Frycztech

Member
2017-05-18 12:09 pm
I don't have any information on this specific amp. I was hoping that someone who does have this information would give you specifics but no one has yet.

The rail voltage is the positive and negative on the output transistors.

The regulated voltage is the positive and negative voltage on the power supply pins of the op-amps in the preamp section.

The op-amps in the output section (near the bias pots) are likely used with switched voltage to serve as the muting circuit.

Measure the DC voltage across pins 4 and 8 of the 8-pin op-amps.

Perry,

Iam only getting 60mV coming in and out of the 2 LM324D'S