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Need helps with hums, radio station in phono

My room seems to have all kinds of problem with some phono units. In the past, I had quite a bit of problem with getting radio station noise in some phono units but not others. The biggest problem seems to be in my Io Eclipse. I used to be able to fix it by connecting ground lead from tonearm to ground on SUT first (signal went straight to Io). Then last month or so radio station noise came back again and there is nothing much that help short of removing tubes from 3rd stage and reduced gain to 50 dB then use a SUT in the pathway. Sonically, I had not complain with using Dynavector 1:13 SUT although overall the gain is a tad on the high side. With Reed tonearm, I am still quite happy with the result.

Recently I installed Graham arm on my turntable and it gave a new hum problem. As soon as cartridge touch LP, I get quite a bit of a hum but no hum when the needle is lifted. I did not have this problem with Reed. I tried moving Io around as much as my shelf/cable/AC cords allowed. Playing with ferrite thing around cable, lift ground from AC, float ground on SUT, trying placing ERS paper around SUT, cables, Io, connecting ground cable from chassis to chassis of isolated transformer, nothing works. Everything I have is plugged into a power conditioner and Isoclean Isolated transformer. Sometimes the hum went away for a few days then it came back again. My Lamm phono has no such problem. I still really like Io Eclipse sound very much and definitely wants to keep it but I am at my wit's end.
I was told that Versa Dynamic used to make something that supposed to help with this problem but have not been able to locate any on Ebay or a'gon.
suteetat
andyprice44
133 posts
 
I did end up trying the method peter lederman suggested. I used some 3-prong to 2-prong adapters from ace hardware. The only component I left earth grounded with the 3-prong power cord was my phono stage. Then my processor,amp, and turntable are connected to the ground lug on the phono stage chassis. This has totally eliminated all hum at my listening chair. The only way I hear a hum is when I turn the volume up to max and I put my ear next to the tweeter or midrange driver. This is more than satisfactory for me. I never listen to music at max volume or sit right next to the speaker anyway. I do listen to music at 85% of max volume sometimes. I can hear no hum at all at these levels. I am going to leave the adapters in place until I can come up with a better solution.
As a precaution, I added some extra shielding to my phono cable and to my tonearm lead wire. I had some scrap monster speaker cable junk laying around. I cut a 12" length off and stripped the shielding from the wire. I then removed a single strand of copper wire about the same diameter of a hair and wrapped this around my tonearm lead wire in a spiral fashion. I left this wire about 3" long and connected the end to the ground lug on my turntable. Once I had this wire installed I wrapped it in PTFE tape. I also wrapped my phono cable in PTFE (teflon) tape. This has also helped to cut down on EFI/RFI interference. It was a tedious process to hand wrap these cables but, the end result was worth it.

Andy

PS
I am using a VPI classic 1 with the exposed wire coming out of the tonearm head. This wire is un-shielded and was picking up interference. That is why I grounded it and added shielding.
atmasphere's avatar
atmasphere
7,068 posts
 
Hi Andy, now that you know a way to fix it, the next step is to find a way to correct the grounding problems that cause the need to lift AC grounds from the wall.

For example what happens if the DAC is unplugged from the wall? Ca you ground everything else normally? If not, then the DAC may be off the hook.

FWIW, in the old days grounding the preamp as the heart of the system was considered normal practice. In this day of liabilities, that is no longer considered a good idea.

If you continue to operate things with the grounds lifted, there is a shock and fire hazard if a piece is damaged or has certain types of failures.
andyprice44
133 posts
 
Atmasphere,
I agree with you. I need to go through my components and determine which piece was causing the problem. Then I will find a way to properly ground it. I have been using the setup for a week or so everyday like this. Still no fires or shocks. That doesn't mean that the possibility isn't there so, I don't recommend that anyone leave their system in this configuration. I do have my components plugged into an APS purepower 1050. I feel this makes it a bit safer by preventing overvoltages.
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