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
Test some units of different amperage on just your digital. But remember, each unit improves as it's power supply is improved,so the testing should be repeated for your digital after you've improved the PS to the other units. The sound will go up and up and up. Cheers to a pristine source of AC.
Lak makes a good point about acoustic noise being a potential concern with the Topaz isolation transformer or other comparable devices. I couldn’t find meaningful data on the Topaz model 91095-22 linked to above, but I found this datasheet covering the model 91095-32T, among others, which appears likely to be fairly similar. The spec listed for acoustic noise is "less than 50 db measured at 3 feet from the noise suppressor." Ouch, unless "less than" is actually "a lot less than."

I also note, btw, that the particular listing for the 91095-22 indicates "open box," perhaps indicating that the device was previously purchased and then returned, or was obtained by the seller from a previous user. And in fact despite the indication of "unused" in the listing the power cord pretty clearly shows signs of use, and even a bit of damage, when the photo in which it appears is expanded.

Best regards,
--Al

Thanks to all. And thank you, Al for finding the acoustic noise spec. That unit would need to placed in a separate room.
And I knew that it was not a new item, but did not notice the wear and tear on the PC.

One thing I don't understand is why some iso xfmr's are rated in watts and some are rated in amps.
What size would I need for my 2 digital components...500 watts?
Again, I'll refer to the Tripp-Lite...
http://www.tripplite.com/isolation-transformer-based-power-conditioner-500w-line-noise-reduction-spi...
The ARC CD3, at least in its first version, had a specified power consumption of 40W max. I would think it very unlikely that the power consumption of the Mkii version is much higher than that. The wall wart for the QuteHD DAC is described at the Chord site as:
12v 1A 2.1mm connector. Centre point positive 100V- 240V – 50/60Hz, 1A wall adapter supplied
I seriously doubt that it actually draws anything close to 1 amp at 120V (which would be approximately 120 watts) to be able to supply 1 amp at 12V (which would be approximately 12 watts). And the 1 amp output is presumably its max output rating, and what would be drawn by the DAC is undoubtedly a good deal less than that. And correspondingly the AC current drawn by the wall wart would be considerably less than it would draw when required to supply 1 amp at its output.

So it’s probably very safe to assume that the AC drawn by the DAC + CDP is less than 100 watts. A 500W transformer would therefore provide a margin of more than 5x, which certainly seems comfortable. Intuitively I would start to feel uncomfortable at less than 3x.

If you go to a linear supply for the DAC, though, before finalizing a selection be sure to assess its current draw or power consumption, as it will most likely be a good deal more than the wall wart’s.
One thing I don’t understand is why some iso xfmr’s are rated in watts and some are rated in amps.
Just a different way of specifying things. For a resistive load watts = volts x amps. So you’ll note that it says in the description of the Tripp-Lite Isolator:
Supports combined loads up to 500 watts continuous/4.2A at 120V.
4.2 amps x 120 volts = 504 volt-amps, which for a resistive load = 504 watts.

Best regards,
-- Al

Many thanks, Al. Your knowledge and the time you spend contributing to the forum is much appreciated.
Jim