Trying to figure out how to get rid of noise, help is welcome!

[Jean]

Jean,
Did you, finally solve the problems?
I built an P3A months ago.
I'm fully sactisfied with it.
Time ago, I got hum problems when something was connected to the amp's input. I discover it wasn't a problem within the amp but a ground problem within connection beetwen the player and preamp (P88).
If you didn't solve the trouble, I can help you.

Still working on it. I can't get my tranny with dual bridge configuration to be as silent as a smaller tranny with one bridge mounted outside the chassis. I have also tried another way of grounding everything to the DC star ground, by running the wire from the caps to insulated post where every ground is connected to. It did not good, its just as noisy as when everything was connected to the caps.

The only thing left now is to remove the tranny that I was using and place it outside the chassis just like I did with the temp. setup. I also need to try putting resistors in series with rca grounds.

So, two more things to try.

As i can see on the picture, your chassis ground is connected near the front panel.
Usually it's connected directly beneath the most sensitive input connector. Just connect an inch of wire from the connector's ground to the chassis.

That was just a temp setup, I am not connecting DC ground to AC ground anymore. AC ground is now connected right near the EIC directly to the chassis (less than 1" of wire there). DC ground floats now, its not connected to the chassis in any way.

 

[Jean]

Hello guys!

Problem Solved, no more issues.

No noise with both channels connected or disconnected from the source. There is about 15-20 mvolts dc on outputs.

I went with seperate toroid-bridge-caps per channel instead of one toroid.

- the end .