2. amps-preamps
  3. 193662-143767

Hum in my system; its the turntable R and L interconnects. Huh?

Pioneer PL-570 reconditioned turntable

EAR Phono Box

Cambridge Audio Integrated amp

DALI Floorstanders

I have a very pronounced "Hum" in my system, sounds like a 60cycle hum. I tried all the troubleshooting steps; it originates in the EAR, which has just recently been serviced and has new Goldline tubes. But here is the kicker, if I disconnect the R and L TT interconnects the hum cuts out and I get a fine white noise sound of much less volume. The TT produces the hum in the system even if the TT is unplugged from the wall receptacle. Removing the ground wire from the TT to the EAR has no effect. I can place my ear on the EAR case and hear nothing, dead quiet. A fault inside the TT?

jereeb
jeffbij
116 posts
 

@jereeb   If you are also going to try a different TT, I'd also try a different set of cables, ...any different set of cables.  It could be that one or both of the cables were damaged when you unplugged the EAR out or hooked it back in.  (It happens.)

jereeb OP
5 posts
 

All good suggestions! The cables from the TT are soldered in place, they can't be swapped. I would consider upgrading the cables if when I try my son's TT in the system, the hum goes away,

I did try different cables between the EAR and the amp: no change. And tried a different input on the amp: no change.

jereeb OP
5 posts
 

Update: I took the EAR over to my friends house and tried it in his system. The EAR was quiet. So it's for sure originating in the TT. Odd that the TT will generate this feedback even if its not plugged in. So its not being generated by energy in the TT, it must be related to a internal wiring fault or the picking up of interference. He has an oscilloscope and has offered to hook it up to the TT to look at the sine wave. I'm not an electrical engineer so not sure what I can learn from that. 

I also ran a ground wire from the EAR to the amp: no change. 

I have not tried the TT in another system, or a different TT in my system. More to follow. Thanks to all of you that have shared your expertise. It's a journey... 

More to discover