punch 1100a

[Hexhclass]

The 20 ohm resistors feeding voltage to the op-amp was all open.I replace them along with the diode that's connecting to the RCA shield.Amp will produce audio now but if the gain ports are set to full it will create a noise like a tone.Sound like the horn of a vehicle.If i set the gain half way and increase the input signal it does not behave that way.Any suggestions?

 

[Perry Babin]

With nothing connected to the amp, what is the resistance from the input RCA shield to the primary ground?

 

[Hexhclass]

I saw about 980 ohms

 

[Perry Babin]

If you move the RCA jacks, does that change significantly?

 

[Hexhclass]

If I move the RCA Jack's it does not behave so.

 

[Perry Babin]

?

 

[Hexhclass]

If I move the RCA the noise is gone.I also resolder the RCA ground.

 

[Perry Babin]

So, is that problem resolved?

 

[Hexhclass]

No problem us still there,was just letting you know with no RCA input the noise us not there.

 

[Perry Babin]

Are the ground connections between the RCA shields and the board broken?

 

[Hexhclass]

The connections are not broken.

I am thinking of connecting a 1k resistor from the shield to main ground.Would that solve a ground problem if there is?

 

[Perry Babin]

That's probably the 980 ohms you read previously.