Bottlehead Forum

General Category => General Discussion => Topic started by: Thomasbhartwell on July 17, 2023, 02:47:33 AM

Title: I’ve got a hum all of a sudden!
Post by: Thomasbhartwell on July 17, 2023, 02:47:33 AM

Hi all, I’ve got a Bottlehead Eros2 phono amp which has been working brilliantly for some time, but all of a sudden has developed a hum/buzz in the right output channel….any thoughts of how to investigate/fix it?
Tom

Title: Re: I’ve got a hum all of a sudden!
Post by: Thomasbhartwell on July 17, 2023, 03:49:01 AM

For clarity, I know it’s the Eros because I’ve swapped out my Naim amp and the problem persists, and the hum is there when my turntable is on and off

Title: Re: I’ve got a hum all of a sudden!
Post by: Larpy on July 17, 2023, 05:34:23 AM

Easiest thing to try is to swap the EF86 tubes and see if the hum stays in the same channel.  If it does not, then you have a tube that either needs replacing or its pins cleaned.

If the hum stays in the same channel despite swapping the EF86s, you can experiment with the 6922 tube.
If you have a spare 6922 tube, try it instead of the one installed now.

Other obvious things to consider:  have you moved the Eros recently?  Or moved something else closer to it?  The hum could be coming from a nearby source.

Title: Re: I’ve got a hum all of a sudden!
Post by: Paul Birkeland on July 17, 2023, 06:20:47 AM

I would perform a voltage check.  Also be sure the earthing wire for the TT isn't loose or broken.

Title: Re: I’ve got a hum all of a sudden!
Post by: Thomasbhartwell on July 17, 2023, 06:30:09 AM

Awesome, thank you! I’ll let you know how I get on!

Title: Re: I’ve got a hum all of a sudden!
Post by: Thomasbhartwell on July 19, 2023, 09:33:53 AM

UPDATE! Now the noise is coming out of both channels, and I”ve not changed anything!

Title: Re: I’ve got a hum all of a sudden!
Post by: Paul Birkeland on July 19, 2023, 12:45:33 PM

Now you need to check the voltages in both channels.