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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
suteetat OP
435 posts
 
Thanks for all the advise. I live in an apartment building so creating separate ground for my audio outlet is not possible although several of my friends who live in a house has separate ground rods placed specifically for their audio system. There is no ground switch on my preamp/phono unfortunately but there is a ground/float switch on my T100 SUT. Sometimes floating ground on SUT seems to help but sometimes not.
I talked to TW acustic and there is no provision to connect ground wire to bearing hub and they think that my problem is unlikely to be solved by doing that anyhow!
andyprice44
133 posts
 
I spoke to peter lederman from soundsmith this afternoon. I learned a new trick from him. New to me atleast. He said to only earth ground one piece of your audio equipment. If your equipment has a 3-prong power cord, get a 3-prong to 2-prong adapter. He said this helps to get rid of more ground hum. This makes sense to me as there is less chance of creating a ground loop. I have not had a chance to try this method yet but, I plan to. I am going to earth ground my phono stage and then connect the rest of my components to the grounding lug on my phono, bypassing the grounds on the powercords. I will post results on this method after I give it a try
suteetat OP
435 posts
 
Hmmm... as soon as I posted the message, the hum went away. May be I should complain more often :)

Some equipments do like grounding, even more so than just with 3 prongs AC cord. My Lamm pre/power/phono has extra ground posts on the chassis and I found that background noise is reduced quite a bit more by connecting those ground post to my isolation transformer as well.
atmasphere's avatar
atmasphere
7,068 posts
 
He said to only earth ground one piece of your audio equipment. If your equipment has a 3-prong power cord, get a 3-prong to 2-prong adapter. He said this helps to get rid of more ground hum.

If any of this ever makes a difference there is either a bug in the design or a defect in the equipment; in either case it should be returned to the manufacturer for repair! You should never use a 3-to-2 prong adapter except for testing, as they can cause shock or fire hazard with certain types of failure in the equipment!

Suteetat, without an LP on the platter. you should see if lowering the arm will induce the hum. Having the hum only show up when you lower the arm sounds like an intermittent wiring problem in the arm itself.
jmcgrogan2's avatar
jmcgrogan2
6,346 posts
 
08-07-12: Suteetat
Tbromgard, I tried it only with phono cable as I use Stealth Dream AC cord on my phono unit, not sure where I would find ferrite ring that big!.

I hope that you are using a "Preamp" version of the Dream power cord. The Dream was designed so that it provided "star grounding" for a system. Therefore, the "Preamp" version has a clearer path to ground than the "Digital" or "Amp" versions.
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