xlr to phono, buzzing sound from amp Options

[john11]

Hi and thanks for reading this post.

I just purchased a hrt music streamer pro usb dac to connect my pc to my amp.

The hrt has output via 3pin xlr and my quad 405-3 amp has input via phono so i used a mini xlr to phono adaptor..

Immediately upon plugging in the hrt i heard a loud buzzing sound which fades after the first 10 seconds, this has never happened before but it now happens every time even when the amp is totally disconnected and i am trying to find out why it keeps doing this.

I contacted David from net audio who makes the 405-3's who said it sounds like the bridge rectifier is damaged and it is charging the power supply smoothing capacitors at different rates.

I don't know if this is possible as the capacitors and bridge rectifier are brand new and i choose really high quality vishay units so find it hard to believe they have failed so early.

The mini xlr phono adaptor connects pin 1 and 3 of the xlr to the outer screened cable to the phono and pin 2 is hot.

Do you think it is okay to use these adaptors or are there any compatibility issues as some people do not connect the drain wire.

Any advise on what to do or which way to go would be appreciated.

Many thanks in advance. John.