Best means of isolating digital equipment i.e. DACs, CD transports, wall warts etc.


Is it better to route these digital noise polluters through a conditioner, isolation transformer or both in series?  Is a "digital" power cord sufficient by itself or could it be used with any of the above without negative side effects?  There are a lot of anecdotal observations in many old threads.  Can anyone help clarify based on what they have found?  I'm getting ready to add a dedicated circuit for my audio system and will be reconfiguring power cable connections.
jc4659
Digital noise polluters? Care to elaborate?
You'll get a thousand answers all different. Do some research.
Some power conditioners separate digital components from analog ones.
@erik_squires I'm sure i read this once before and found it helpful though does not directly answer all my questions.  In your article a DAC is considered a noise emitter and I would agree.  Why then do you show it plugged in on the "clean side"?
 In your article a DAC is considered a noise emitter and I would agree.  Why then do you show it plugged in on the "clean side"?

Yeah, I honestly went back and forth, in part because some are powered by wall warts, but then the following point kind of became most prominent:

The DAC starts the analog signal, so it needs clean power.

If your DAC uses a wall wart, I suggest swapping it for a linear supply. If you get aftermarket power cords, shielded cords (which are cheap) are recommended to prevent radiating, and receiving noise.

As for dedicated digital cables... I'd have to see the specific item you are referring to. :)


I have two dedicated digital power cables.  A shunyata alpha digital and a Signal Cable digital power cable.

The best way to isolate DACs and CDP is Craig's List. I recommend listing under "free stuff" as that gets them gone faster. But you are welcome to try and get something for them if you think you can.

A wall wart is nothing more than a small transformer, diodes, and cap. The solution to wall warts is not to isolate but to improve. Swap out the cheap parts and hard wire better quality cap and diode. Or if you can't solder then contact Michael Spallone about modding them. 

Ideally you would sell the DAC for enough to cover Spallone.
Is that what you did to fund the Moabs?

Post removed 
Could someone tell Miller that Wall-Warts have not been "a small transformer, diodes and cap", with rare exception for quite some time. Most are switch mode supplies not due to the requirement of universal operation and cost.
Is that what you did to fund the Moabs?

Good one. Hilarious. Good luck. Given the people helping so far you're gonna need it.
@audio2design It would make the forums a better place if you could post disagreements and corrections without appending personal attacks. 
I'll give it a shot.

Wall-Warts have not been "a small transformer, diodes and cap", with rare exception for quite some time. Most are switch mode supplies not due to the requirement of universal operation and cost.
I am trying to use language that he will understand, using his particular vernacular, except i tend to be more targeted where he just insults everyone :-)   
cal37131,132 posts01-10-2021 9:57pm@audio2design It would make the forums a better place if you could post disagreements and corrections without appending personal attacks.


putting the DAC on the clean or dirty side depends on two or three issues.

Linear or switching power supply?, Switch = dirty

Ladder or chip ?, IF chip with Faraday cage = clean,  IF not then dirty

Chip vs. analog display or switching ? see ARC and Aesthetix defeat of those w improved sonics, otherwise = dirty

finally listen

always use a quality power conditioning and a dedicated line for dirty


 i did a quick Craigslist search for MSB, DCS, Aesthetix, Benchmark and Bricasti...Weiss, Wadia Pro, etc...no luck...must be the musings of a wishful egotist...
but to come back and nail down your question a bit more. In my reference system I have essentially 3 dedicated circuits back to the panel for audio: Low level analog w power conditioning, Digital wall warts, server ( even w linear supply as it has no Faraday cage ) , streamer, network switch all on a seperate line and power conditioning, finally monoblocks w no conditioning on a third line ( split from 240 ).

experiment and listen
@tomic601 I don't have the luxury of 3 dedicated circuits; I will only be able to add one.  Right now I have my analog plus ayre codex DAC plugged into a hydra 2 conditioner (clean side).  I use a distributor to gain extra outlets since the hydra only has two.  All devices which use a switching power supply are plugged into a power strip which is plugged into a MGE 250VA isolation transformer.  I am assuming this prevents noise from going back into the circuit.  Please correct me if I have this wrong.
Eric, you have to be careful with Parts Connexion. They can be a terrible rip off. They sell 14 gauge three conductor shielded power cable for $100/linear foot. But here is basically the same stuff for $3.00/linear foot
https://www.wireandcableyourway.com/belden-9367-14-awg-1-triad-shielded-300v-power-limited-tray-cabl...
You can make a wonderful shielded power cord for $45.00 and make them to fit perfectly. 
If your power is reasonably clean all you need is shielded power cord not only to keep stuff out but to keep stuff in, isolating your interconnects from the power cord. 
In reality there is no such thing as a dedicated line. It all goes back to the same panel and mains. The individual lines are sized to the circuit breakers. Very few system in their entirety are going to trip a 20 amp breaker. Adding more current capability may make you feel better but it will not improve the sound in any way. As far as noise is concerned all the stuff in the house is connected to that panel. So, see if any of it causes noise. Turn your system all the way up and turn an the AC. Stick your head in the speaker. Do you hear it? Next the refrigerator. Turn down the thermostat. Do you hear it in the speaker? What about the washing machine or the blender. If you have good components you will not hear a darn thing and if you do not hear a darn thing forget about it. You do not have a problem so stop wasting money on a problem you do not have. 
two lines are fine, i would swap the Hydra and the Transformer and see which sounds better.

on the post above, maybe...but first get your audio clean circuit off the dirty leg of the AC panel, that is the one with refrig compressor and motors.

also good to tighten your panel connections including grounds on a periodic basis - dont do any of the work i mentioned in this post if unqualified.
@jc4659 - the best way I have found to isolate components of any kind is to ensure they are NOT plugged into receptacles that are "daisy chained" together in a parallel configuration.

The daisy chained approach is often used in many power strips and power conditioners - so I avoid using them

I have one outlet providing power to my entire system...
  • connected to that outlet is an extension lead with a single dual outlet on the other end
  • into that is connected my amp and a second power distribution box
  • each outlet in the distribution box is linked via it’s own pieces of wire to common neutral and live connection points
  • that, in effect, connects each device directly back to the wall outlet
  • so it is as though each device is plugged into it’s own wall outlet

This seems to eliminate any noise pollution issue in my system.

I also use very good power cables that eliminate cable generated noise, so the background of my system is extremely quiet.

regards - Steve
@williewonka Thanks for the details.  What power cables are you using?
@tomic601 I did that swap and and my system sounds more clear with the analog going into the hydra.  A few years ago, different equipment and different room, the best I obtained was when the preamp was plugged into the iso tranny by itself with the digital feeding the hydra so totally opposite to how I have it set up now.  You would think having an isolation transformer at the front of everything would be ideal.  Once I have a dedicated line installed with outlets closer to my equipment I will be more judicious about using anything other than the cords themselves initially, then systematically try the conditioner and iso tranny.
@williewonka I would think that your power cords are making more of a difference than avoiding the daisy chain since they are all tied together at the wall but I'm not an EE.
@jc4659 RE:
@williewonka I would think that your power cords are making more of a difference than avoiding the daisy chain since they are all tied together at the wall but I’m not an EE.
I might have agreed with your statement IF I had implemented everything at the same time, but I developed my distribution box long before I got into building power cables. The distribution box proved beneficial immediately using the stock power cables that came with the components.

@cal3713 - I started by building my own cables using Bulk cable from companies like Furutech and DH Labs, but now I build my own cables - see this link
**The HELIX IMAGE Power Cable | My Audio Alchemy (image99.net)

Read what other members think of them here...
https://forum.audiogon.com/posts/2085763

If you are not into DIY I would recommend power cables from KLE Innovations or Nordost.

Hope that helps - Steve

@williewonka Thanks for the details, they look great.
Nice cords!  Beautiful photography.