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Help needed with 50hz hum/buzz in Tube system

My high power tube VTL system is not quite there. I ran seperate outlets on different ciruits for both Mono block amps and the Digital front end which runs through a panamax 5500. The problem is that there is a 50hz buzz/hum comming through both speakers the woofer and tweeter. I connected an ipod to the amps directly and they have a silent background, But when the preamp in connected to the amps the hum returns. The turntable / phono section is even worse. Someone told me that there is a possibilty that the isolated outlets are wired on "opposing legs" of the incomming 220 line.

This afternoon this afternoon I removed the ground pin of the PS audio power cables and problem solved. It seems that Every component in this system must have the ground pin removed, because one I connect another component that is grounded the problem returns.

Any suggestions on what the proper fix to eleviate this issue should be? Thanks again to all for their time

PS if you are a professional electrician working in the rockaways/LI area and would like to take a shot at fixing this let me know
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audphile1's avatar
audphile1
4,919 posts
 
Wait with the electrician. Try this first.

disconnect the coax cable(cable tv) at its first point of entry into your house. Unplugging the cable box won't do. You need to take the coax cable out.
Then put the ground pins back on the PS Audio cables. Turn on your stereo system and see if it humms.
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swampwalker
5,138 posts
 
I suspect it is the cable TV and there is a very easy fix. If after trying Audphile1s suggestion and finding it works, just get a ground isolation transformer for the coax. From Rat shack $10 from Modial (called Magic) $100, lots of others at in between prices.
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weiserb OP
476 posts
 
I did already disconnect the link to the cable by removing the connection between my receiver and my preamp. that did not change anything . Only removing the ground pins solved the problem. I can disconnect the cable line and see if that changes anything. I think it has something to do with the way the outlets are wired to the electrical panel. FYI I looked up ground loop on Wikipedia and got a ton of really cool stuff to read on ground loops, detection devices, and more. probably 50 pages of information. But my # 1 trusted source is Audiogon. I have never had an unresolved problem once posted here.
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audphile1
4,919 posts
 
Weiserb, you have to take the coax cable out of the box. Disconnecting the receiver to preamp connection will not do. It is not on the connection level.
Please take out the coax cable from the cable box and re-check.
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weiserb OP
476 posts
 
Update. I spoke to Ryan at PS Audio and he said that there is a different grounding potential on the circuits powering the front end and the power amplifiers , and an electrician should correct the above and add an isolated grounding rod for all circuits for the stereo. In addition as mentioned above connecting the cable line may reintroduce the problem and require an Isolation Transformer from the Jensen company.
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