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Bah Hum Bug

I am having an issue with hum.Hum is only apparent in very quiet passages while listening to lps or when unit is in idle mode.Unit is Dead quiet..no hum in cd mode of operation.

I am running a Fosgate Signature Phono amp,Thorens Td124 with Ortofon Silver Meister Cart,Wright AU-1000 linestage, 2A3 SET power amp into Klipsch Heresy speakers.

When ground is is attached from TT to Phono amp the hum is intolerable so I run the TT with no ground to Phono amp.

I have tried cheater plugs and that has made no difference.

When volume is turned up say past 1 oclock in either the Wright or the power amp the hum is very noticable. Is this indicative of the high efficiency of the Heresys and 2A3 tubes? or is there some other thing going on here?

Please help.Thanks.
fromunda
marakanetz's avatar
marakanetz
5,473 posts
 
2nd to Jmc.
fingerpaws
51 posts
 
I have had similar problems and it was the cable that connected the arm to the phono preamp. However, I can easily get noise if I raise the gain too much. I mean more gain than it would need to be very loud. So, I agree with those who suggest cable problems. I use a very low output moving coil, and perhaps a "louder" cartridge would be worth a try. I use Kimber Silver Streak between my Denon 100th anniversary cartridge and Parasound JC-3. Pre amp is Audio Research LS 17. I need very little gain for high volume, and I am frankly surprised by how quiet it is. Good luck, you may need to find a helpful shop.
fromunda OP
146 posts
 
All equipment is plugged into Fuman Elite power conditioner
manitunc
795 posts
 
+2 on the phono cable. Drove me nuts with my Manley Steelhead. Changed tables and arms and cables until It is now silent. does the level of hum change at all if you move the phono cable around. that might help isolate if its due to proximaty to a hum source, or possibly a small break in the cable sheathing. You just have to work through a process of elimiation.
fineito
34 posts
 
Fromunda, I had the exact same problem as you. It was phono stage related. I tried cheater plugs, not much difference. I ended up purchasing the Granite Audio 502 Ground Zero and that seems to have worked for me, with some experimentation of settings. Let's just say that I am no longer cognizant of the hum at higher volumes without a signal. Maybe it is still there, I don't know, but I've not fixated on it since the 502. I've moved on. All the above advice is good. Clean you interconnect contacts, too. they could be dirty with poor contact. Lastly, I had an expensive Kondo KSL silver interconnect short circuit internally. Kondo repaired, and it is as good as new now. That caused a very loud hum different from your's.Still, clean the contacts.
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