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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

Showing 3 responses by atmasphere

atmasphere's avatar
atmasphere
12,116 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.
atmasphere's avatar
atmasphere
12,116 posts
 
Huh? Not buying that one.
atmasphere's avatar
atmasphere
12,116 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.
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