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Phono stage hum

Dipping my toe into Tubes for first time.

Have been using simaudio moon lp5.3 phone stage.

today trying Manley Chinook tube stage.

getting what sounds like ground loop hum with the chinook and my thorens 160 super... tried with a different turntable (cheap teac) and no hum....

any ideas? 
otherones
noromance's avatar
noromance
9,766 posts
 
Check all the ground wires inc the one on the chassis. Run a test wire from the Chinook ground lug to the chassis to see if it resolves it.

otherones OP
13 posts
 
I appreciate the tips but the hum didn't go away.
A few other notes:
  • The hum is on both speakers
  • The hum increases/decreases with volume
  • The hum is 'mostly' drowned out with music playing but still audible and very audible in between tracks or during quiet parts of song
  • Thorens turntable + Sim Audio LP5.3 (solid state phono stage)= No Hum
  • Thorens turntable + Chinook (tube phono stage) = HUM
  • Teac turntable + Chinook (tube phono stage) = No hum
It is sad b/c I really like the sound of the Chinook but will probably return it in a couple days b/c I won't be able to stand the hum.
If anyone has other troubleshooting ideas, I'd be grateful :)
rotaryphone
159 posts
 
Do you place two TT on the same spot?

I would move the phono amp away from the other equipment as far as you can and see what happens. 
otherones OP
13 posts
 
Both TT tested in same spot and I have also tried moving the phono stage as far away as I could... same result 
noromance's avatar
noromance
9,766 posts
 
Try using a cheater plug on the amp. This removes the ground connection and therefore the loop. 
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