I have tried ERS extensively over a 10-year modding career. I found that it was most effective right over the drive. I would avoid other digital or analog areas of the player.
I can't say that I've gone as far as trying ERS cloth inside components. I got as far as trying it around cables and on top of various components in large, medium and small sizes of the material. I experimented with ERS cloth in two highly resolving system over the course of two days. The results were consistent - while the ERS cloth affected the sound, even in small amounts, the sound lost its sparkle and sounded rather compressed and wooly. I found out that even having a sheet of ERS material sitting on the coffee table hurt the sound.
This is one of those products you have to experiment with, too much and you'll get the results that Geoffkait notes as I too have experienced. I've been using it for about 10 years. It DOES work in making things quieter but you don't want it to interfer with the music either, just noise from RFI/EMI. Best thing is to buy a sheet and experiment. I have it on the small transformers in my Berning amp. I also had it on over the impedance converters in the amp but discovered after removing it over a period of time some of the sparkle in the music came back without gaining noise. Results can be dramatic or subtle. You can try a small piece on the top of different components and see what happens. It's effect is going to be different depending on the system, noise your system is picking up and other things unknown, the audio voodoo gremlins. I'm not sure there is a clear answer, in any case use judiciously and DON'T line the inside of any component, I doubt you'll like the result.
My experience parallels those of Geofkait and Tubegroover. This stuff is like Cilantro - you have to get the proportion just right. I actually wound up cutting the sheets into very small strips and dots - nothing bigger than a half inch square. I used them on top of my CDP, moving them around by ear. I finally gave them up as being too tweaky after a cleaning lady broke through all my defenses and dusted my system.
I taped cut pieces around the transformers in the power supply of my Steelhead,on top of some caps,and around the power IEC.
I also wrapped another smaller linear power supply to my LTS volume control.
I put some on top of my Furman IT 1500 balanced power unit(over transformer but outside unit),and a small piece under one of my Furutech GTX D reptacles which sits out from the wall on a DIY platform on the floor which powers up the Furman and my two Acoustat servo amps.
There are a few places I would like to try the cloth,inside the Furman,which I will do when I order some more.
I also did some DIY shielding to the open wires inside both of the Steelhead chassis.I taped some pads under the metal chassis where the transformers are ,this time on the outside.
The end result is my vinyl sounds more focused.Instruments and vocals are easier to make out.
There's better differentiation.
I wrapped the transformer in my Furman balanced power conditioner because I noticed that this is what BPT does to the transformer in their units.
It made an improvement in my Furman, so I bought more sheets and wrapped every transformer I could throughout my system.
I don't know if it is shielding incoming EMI/RFI or outgoing from the gear.
All I know is that I like the results.
If I ever come across mu-metal and it's as cheap as the ERS, I'll certainly give that a try.
Something tells me that cutting and fitting cloth is easier than cutting and fitting metal.
I use electrical tape to affix the cloth.
What would you use to attach mu metal to a transformer?
Mu metal is not expensive, I'm guessing the same price per square foot as the Stillpoints stuff and can be wrapped around the transformer since it comes in thin malleable sheets that can be easily cut and also placed below and over the transformer. The issue of course is the powerful and toxic magnetic field produced by the transformer as a consequence of you know the current traveling through the wire, not to be confused with an electromagnetic field, that affects everything within proximity. One layer of mu metal absorbs about 75 % of the magnetic field, while two layers absorb about 96% of the magnetic field, which you recall from high school is orthogonal to the direction of the current flow.
Thanks Geoffkait. you are a great contributor. However you mention "you recall from high school days" would only be wishful thinking on my part! Are you saying the magnetic field from the transformer contributes as much noise as EMI/RFI. Does wrapping with mu-metal cause any problems. I also have a ~ 75 pound Equitech 2Q transformer. They don't appear to have it enclosed in mu-metal Any idea why?
"Are you saying the magnetic field from the transformer contributes as much noise as EMI/RFI?"
I'm saying it contributes more.
"Does wrapping with mu-metal cause any problems?"
Mu metal is conductive so one needs to be soemwhat careful. Usually the transformer is easily wrapped
"I also have a ~ 75 pound Equitech 2Q transformer. They don't appear to have it enclosed in mu-metal Any idea why?
My guess is either they don't know or don't care. I can't think of any manufacturers who enclose the transformer in mu metal. Go figure. Of course they don't do a lot of things, E.g., better fuses in, better power cords.
I've used mu metal in a couple of DIY projects with good results. I also covered the transformer inside my Lamm LL2 preamp and cannot hear a difference. Maybe it is shielded well enough already.
About a year ago I wanted to tackle EMI/RFI inside my digital: Metrum Octave DAC, Audiophilleo and purpose-built PC. At the time I was advised to try 3M EMI Absorber AB5100S instead of ERS cloth. My recollection of the reasons were better performance and that ERS cloth, being cloth, exposes us to the risk of loose conductive fibers inside an electric appliance - must be handled with care.
I bought the 3M "paper". It's not paper, really. It's 1mm thick, doesn't bend, and it's heavy. And worked very well for me. The edges are also conductive, so you want to line them with tape. Never used ERS so can't comment on it.
In my DAC, PC and AP I covered 3 faces of the box: one of each parallel faces inside the box. Also applied small pieces around clocks, integrated circuits, etc. around clocks I applied several layers. I wasn't patient enough to try out various combinations of varying layers in different places. But the impact was positive and noticeable. I crafted a box around my PPA USB card, taped it with vinyl tape, tripple-layered on top of it's clock, etc.
Another nice place to try this was in the circuit breaker box, on the inside of the box door, right in front of the circuit breakers themselves.
Very good product. A lot of user input over at JPlay/Computer Audio forum. Many DIY hard-core explorers there.
Never had luck with ERS, oh! well. Too phasey for me. But I did have good results with the 3M AB5100S on the AC cord coming into the player, on ribbon cables inside the player, those weird short 12 wire connectors, also on chips. Two layers of mu metal all around the transformer is noticeably better than one layer, but leave a space of say 1/4 between layers. I also strongly recommend pure natural cork 1/8" thick under any transformer and remove the bolt or at least loosen it. The bolt is a good idea only for shipping. It couples the 60 Hz hum to the chassis. Hel-loo! Finally, 1/8" cork spacers should be placed below all circuit boards. You know, to isolate them from the stupid transformer.