Strange buzzing sound from phono stage

[wilro15]

I am experiencing a strange buzzing sound (sounds like a ground loop feedback noise or an 8bit beepy noise) which seems to come from my phono stage.

My system is: Technics SL1210 -> Rega Fono MM -> Roksan Caspian M2 integrated.

All morning I have been listening to music from my Bluesound Node, no problems at all (I am working from home!). I thought I would switch to some vinyl for a bit, I have just replaced the stylus so wanted to check it out. After about 5 minutes into the LP the buzzing starts - pretty loud - out of both speakers.

I stop the record & turn off the Technics - still buzzing. I then change the input on the Roksan to an unused line in - STILL buzzing! I then turn off the Rega phono stage - still buzzing but gets quieter.

The weird thing is if I touch the Rega phono stage, the buzzing goes very quiet. As soon as I let go of it, it comes back. I can repeat this over and over again. So it seems like I am grounding the phono stage when I touch it - but why is this happening?

 

[TrevC]

I am experiencing a strange buzzing sound (sounds like a ground loop feedback noise or an 8bit beepy noise) which seems to come from my phono stage.

My system is: Technics SL1210 -> Rega Fono MM -> Roksan Caspian M2 integrated.

All morning I have been listening to music from my Bluesound Node, no problems at all (I am working from home!). I thought I would switch to some vinyl for a bit, I have just replaced the stylus so wanted to check it out. After about 5 minutes into the LP the buzzing starts - pretty loud - out of both speakers.

I stop the record & turn off the Technics - still buzzing. I then change the input on the Roksan to an unused line in - STILL buzzing! I then turn off the Rega phono stage - still buzzing but gets quieter.

The weird thing is if I touch the Rega phono stage, the buzzing goes very quiet. As soon as I let go of it, it comes back. I can repeat this over and over again. So it seems like I am grounding the phono stage when I touch it - but why is this happening?

Does it buzz with the Bluesound thing powered down?

 

[wilro15]

Yep. I switched off my DAC and the other digital bits and bobs and was still buzzing.

I managed to "fix" it by unplugging the Technics RCA leads from the Rega, then plugging them back in again. Managed to listen to 3 more LPs without an issue.

I'm expecting it to happen again, but looks ok for now.

 

[nopiano]

If one of the Technics phono leads had become slightly loose that would have broken the ground. Removing and reinserting it fully must have fixed that.

I did wonder if you'd disturbed a cartridge wire while changing the stylus, but hopefully not.