Mtx ta92001 distorted output.

[kfx5050]

+0.009 volt this is a 50hz test tone. by the RCA input

 

[Perry Babin]

The 0.009v is DC. You're looking for AC. Here you have 2+v of signal.

Was the preamp board plugged in when you checked on the other op-amp?

If not, do you have any computer circuit board/hard drive shunts?

 

[kfx5050]

no the preamp board is disconnected.has been disconnected during this whole time. no computer circuit board or hard drive shunts. I do have some old xtant jumper

 

[Perry Babin]

Audio passes from the main board to the preamp board and back. You have to jump as shown in the attached photo if the preamp board isn't plugged in or working.

 

[kfx5050]

with the jumper install the op-amp buy the ribbon cable for the pre amp board across pin 1 and 7 I am getting 50hz at 1.958 volts

 

[Perry Babin]

Do you now have audio or a square wave of the audio frequency on the output of the op-amps near the opto-couplers?

 

[kfx5050]

op amp close to led400. I have the 60hz sound wave across pin 1&7 but the op amp close to the heat sink I have nothing

 

[Perry Babin]

The 5534s have a different pin configuration. For these, check for signal on pin 6 with the black probe on ground (negative speaker terminal).

Did you mean that you had a 50Hz sine wave or are you picking up noise from the 60Hz mains (common when fluorescent lights are nearby)?

 

[kfx5050]

yes there are four fluorescent lights here in my work area
no output on pin 6 from nether op amps

 

[Perry Babin]

Is signal making it to the two points in the photo?

 

[kfx5050]

At the resistor yes at the op amp no.

 

[Perry Babin]

Confirm that you have audio on both pins 1 and 7 of the 5532 near the header.

 

[kfx5050]

yes I have the 50hz tone on pin 1&7 near the pre amp board plug

 

[Perry Babin]

Is R4011 within tolerance?

Do you read 2000 ohms between pin 1 of the header op-amp and pin 3 of the op-amp near the heatsink?

 

[kfx5050]

R4011 is showing 1.832kohms

The op-amp right cross from r4011 the one closest to the heatsink is what your referring too right? If so, It's reading 1.824kohms

 

[Perry Babin]

I'm trying to determine why the signal isn't making it from the dual op-amp near the header to the two inputs on the 5534. You won't see the input to the inverting input while the op-amp is functioning normally but you should see it on the non-inverting (pin 3) input.

 

[kfx5050]

Ok I order a new radio just arrived. I have a 50hz test tone at 1.055volts going into the amp on one side of r4016 I have the 50hz tone on the ather side I do not have the 50hz tone

 

[Perry Babin]

On R4016, you should only see the signal on one side of the resistor. On R4011, you should see it on both terminals.

 

[kfx5050]

On r4011 I only have one 50hz on one side of it. The ather side I do not.

 

[kfx5050]

I removed R4011 resistor. I have 50hz test tone on the resistor pad comeing from the header. The other side of the resistor pad going to pin 3 of the op-amp I do not have 50hz. I check to make shore the Trace comeing from pin 3 to the resistor r4011 is not damaged by setting the meter to continuity. It checks out good. Does this mean resistor R4011 is bad?