Quad 405 (MK 1) Buzz / Hum

[xtal_recorder]

Hi all,

My newly acquired 405 is making a hum / buzz from both speakers even when not connected to the 44 pre.

I don't think it's been turned on in a while and likely needs a service but it sounds like a ground loop..

Does anyone have any ideas as to what I could try?

Thank you!

 

[xtal_recorder]

If I connect it to the 44 and turn it on, the buzz is still there but not as loud.

I'm connecting both the mains with 3-core cable.

 

[Barrymagrec]

If there`s nothing else connected it can`t be a ground loop, there could be other problems though.

The 405 is known for hum caused by a single small cap - old thread here:-

Quad 405/2 noise/hum

I have recently had a problem with a noise coming from my quad 405/2. This was from the r speaker. I swopped speaker leads and yes, it now comes from the left. I know this is not from the the 44 pre amp having disconnected it and had the 405 on its own with no input. Not being fully...

pinkfishmedia.net

 

[xtal_recorder]

Thanks @Barrymagrec yes the buzz happens when just the speakers are connected.

I think the 44 and 405 are probably long overdue a service...

 

[davidsrsb]

A 405 MK1 is at least 42 years old, so a very long time if never serviced.