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Will an Isolation Transformer Help My Digital?

I am experiencing noise from my digital components into my system. It presents as high frequency interference thru the speakers once the components are warmed up. This interference is being sent back to the mains and can be heard when music is being played or idle.

I’m using an ARC CD3 mk II CDP, Chord DAC, and a NAD CD player. I have a 20 amp dedicated line with Blue Circle power conditioning at the wall.
A Furman power strip for the low-current analogue components is plugged into the PC. Also feeding from the PC is a Tripp-Lite Isobar with isolated filter banks for the digital. The toroidal chokes in this Tripp-Lite power strip are not able to filter the digital noise.
My amp plugs into the wall duplex outlet.

I posted a thread earlier where it was mentioned than an isolation transformer used exclusively for the digital components might resolve the noise/interference problem.
I read in the archives about the use of a Tripp Lite IS250HG Isolation Transformer to isolate the CDP/DAC.

https://www.amazon.com/dp/B0000ET7Q6/ref=wl_it_dp_o_pC_nS_img?_encoding=UTF8&colid=29XG41GAZ363K...

So, I’m asking if this would be a solution, since I don’t plan on running another dedicated line. (too many reasons to list).
128x128lowrider57
lowrider57's avatar
lowrider57 OP
5,417 posts
 
Hi Al.
See my explanation of the grounding theory. These early units were sold as a set.

And you’re correct that the noise was eliminated when CDP was plugged into different and more distant outlets.
Given that the noise was considerably less when you used the CDP’s stock power cord instead of the upgraded power cords you tried (the upgraded cords presumably having greater bandwidth than the stock cord, and therefore providing less attenuation of high frequency noise over a significant part of the spectrum)
Once again, correct. But, the noise was not eliminated. And now that I’m using a SMPS wall-wart for the DAC, the noise is considerably louder than a dedicated CDP. I intend to upgrade to a linear power supply.
lowrider57's avatar
lowrider57 OP
5,417 posts
 
@lak,
Always appreciate your participation. I found a thread where you speak to using an isolation transformer for the entire audio system, as you have done in your own house.
https://forum.audiogon.com/discussions/isolation-transformer-2?highlight=isolation%2Btransformer%2Bc...

Do you have any thoughts on using a iso transformer on the front-end of my system if indeed digital noise is being introduced?

terry9
2,354 posts
 
Lowrider, I'll bet the wall-wart is a switching power supply. If so, it may be feeding noise back into your wall. Why not try an old laboratory power supply capable of the same voltage, instead of the wall-wart? "Old" being the operative word, before switchers became the order of the day.

Just a wild guess.

lowrider57's avatar
lowrider57 OP
5,417 posts
 
terry, I'm sure your right since it is a switching power supply. I plan an upgrade, but that's not a bad idea as a test. Too bad I don't work with the bench tech guys anymore.

whart's avatar
whart
3,064 posts
 
Low- on the linear power supply, take a look at the product in the link below. I bought one in part because it was cheap, it has a large toroidal transformer, multiple channels for setting voltage and current limit (with read-outs) as well as a channel with fixed voltage/current. I am not using it for an audio component as such (rather, for one of those Acoustic Revive Schumann resonance generators which may put me in the category of "fringe"/voodoo, I dunno), but it seems like a good value.
http://www.loneoceans.com/labs/tekpower/ (Note that the writer compares it to two ’look-alike’ units that are also available, as this one is, on Amazon).
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