Pioneer A400 amp - Right red output makes right tweeter buzz.

Maks Swiderek

Aug 11, 2015
I have 2 Wharfdale Rubiance RB-25 speakers connected to my Pioneer A400 amp. Since I connected them I've noticed that no mater what the configuration, the right red output creates buzz at around the higher end of vocal frequency (~3kHz). This is confirmed for different inputs (CD, Phono and line in (PC)).

I've tried separating audio and power cables.
I've rewired the speakers and swapped the speakers also.
I've tried re-grounding the photo TT.

How do i fix the buzzing?
You might have a ground loop.
Disconnect all the input cables and turn the A400 on. If the noise is still there then it is an internal problem in the A400.
If not then reconnect each source one at a time, turn the A400 on and listen. When the noise returns you will need to either break the ground at the AC cords or with an ground isolating transformer in the audio line.