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electrical isolation of amp and other gear

I have a question about power and isolation involving an amp and other gear. Apologies if this is not the right forum.

I have (or will soon have) 3 primary audio devices:
- Pass Labs XA30.8 amp
- Lampizator Golden Gate DAC (with volume control)
- Sonore Signature Rendu SE streamer

My understanding is that that recommendation is to electrically isolate digital gear from analog gear (in terms of lines, outlets, power conditioners, etc.) However, both of the digital units that I have use linear power supplies, so I wonder if that isolation is still necessary in my case.

I also have a Furman Elite-20pfi power conditioner in which I plug some other devices (SonicTransporter that feeds the streamer as well as pro audio/guitar gear unrelated to the hi-fi system). So, with the above gear, I will have a total 4 devices to plug into the wall (the amp and DAC tend to sound better plugged into the wall then through the power conditioner).

I have 3 dedicated lines. Each one has different outlets - Furutech GTX-D NCF(R), SR Blue, Maestro. I’ll plug the power conditioner into one of them. My question is how should I group the other two? Here are some options:

- amp in 1 outlet, DAC and streamer together on 1 outlet, power conditioner on 1 outlet
- amp in 1 outlet, DAC 1 outlet, power conditioner on 1 outlet, streamer in an isolated bank in the power conditioner.

Are there other options that I should be considering? If there is no advantage to isolating gear with linear power supplies, I might as well go with the first option. At the end of the day, I’ll let me ears do the final judging. However, with all the possible options as well as the combinations of mating different pieces of gear with different outlets, there are a ton of permutations and combinations. So, I’m looking for general guidelines as a starting point.
strats

Showing 3 responses by erik_squires

erik_squires
15,643 posts
 
That's pretty much correct.

Inside the audio devices, the two biggest sources of noise are digital processors and switching power supplies, and now, networking devices. Frequencies here are from 10kHz to GHz.So, your DAC, streamer, DSP, or Class D amps, etc. can potentially cross-contaminate.

Using a shielded cable for these reduces the chance of this noise making it elsewhere. Keeping these potentially noisy sources outside the clean zone your linear devices are on makes sense.

Linear supplies can generate switching noise from the diodes in the bridge rectifiers, but in general it's accepted this, when it exists, is of smaller magnitude, lower frequency and easier to deal with.


erik_squires
15,643 posts
 
Yeah, cross contamination is still a possible issue.

I like to use the cheapest Furman with LiFT and SMP for those digital sources.


https://amzn.to/2HEq6pC

This puts them 2 filters away from my audio, and compared to a lot of audiophile power strips, a real bargain.
erik_squires
15,643 posts
 
The Furman unit you have has multiple filtered banks, so you can definitely use it for all your gear.

With the DAC, it is recommended by PS Audio, and I concur, to use shielded AC cables to keep the digital component noise emitted down. Even if you use a linear power supply ( a good idea ) DAC's are essentially computers with linear outputs. Digital tech can produce a lot of EMI/RFI which can possibly escape the power supply.
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