Linear Power supplies for DACs...?

Is there real SQ benefits or is it placebo snake oil?
i have a Chord Qutest and it has a wall wart. Lots of people say there’s real benefit to adding an external LPS. 
Plenty of choices ranging from $50 - $500.
Sure, a home audition is ideal.

but, what do you guys think?

Not just for the Qutest, but in general for DACs.

My biggest concern with wall warts is the noise they could inject into the AC line which gets picked up elsewhere. Putting a noise source AFTER a power conditioner without separate filter banks could allow it to inject noise into your previously clean power.

For this reason I like to keep networking wall warts outside of my power conditioner’s clean zone, and use an iFi to power my streamer.

I don’t think it’s worth major moolah, but an iFi wall wart or inexpensive LPS can be useful vs. cheap alternatives.

I also like to use shielded power cables.  Again, not major dough here, but another way to keep external network noise and EMI/RFI out of my system.

If not, buy a new DAC yours must be pretty old and junk since even cheap ones now have pretty good filters. In others words it’s placebo. Good modern DACs work really well with whatever power supply they came with.

@djones51 Thanks for letting me know that I have three placebos on my rack. My listening skills and those of others who have heard my system must be in question, so take the rest of my post with a healthy grain of salt.

I first bought a MCRU linear power supply for my Arcam irDAC. The MCRU was souped up for me at the factory and had a Furutech rhodium IEC socket and fuse, and a pure silver DC tail. Adding this lps to my system made a very positive difference in the sound of the DAC, better bass, less hash in the mids, and smoother highs. Overall an improvement over the stock switching power supply. When I upgraded my DAC to a Chord QuteHD, the 12V MCRU improved the performance of that DAC as well compared to the stock smps. I am now using a Chord Qutest DAC and Bluesound N130 as a streamer/server, and I have ordered a Teddy Pardo Dual 5V LPs to supply both devices. I will report on how that works.

I was so pleased with the performance of the MCRU supply that I bought a Swagman SE linear supply for my Pro-Ject Tube Box DS to replace its switching supply, and again, a noticeable improvement. I have since added a less built out lps for my Amazon Firebox, the goal being to eliminate smps from my system entirely.

I can’t tell if the benefit of replacing smps with lps is accrued at the component or system level, or to what portion of each the benefit applies. I just know for my ears in my system the benefits are real. My reason for going in this direction was the fact that Naim and many high end makers of digital gear routinely put capable linear power supplies in separate boxes, and the performance of the improved power supplies are routinely lauded by audiophiles and reviewers alike.

Adding an lps also allows me to explore using different power cables, which in my system, also can make remarkably large differences in how my gear sounds. The differences are significant and not always good. As someone who assembles many of my own PCs, this allows me more ways to experiment with different materials and designs to see what works best in different applications. I have a fairly busy rack, with AV, analog and digital front ends, and keeping signals in their own lanes and noise contained may be of greater importance for me, ymmv.

I use a Shunyata power supply/conditioning, so there is some filtering from the wall and between components. I also have a dedicated power line from the breaker box and my listening room is purpose built for audio, so I have put significant thought and time into maximizing the performance of my fairly modest components.

Why are some higher end manufacturers going to switching supplies?  Well, in Europe, power consumption is an important issue, and there is no question that linear power supplies are less efficient than smps. Switching supplies have gotten quieter and more robust, perhaps as a result of efficiency driven demand for less power use and better performance. The stock switching power supply on my Qutest DAC is pretty good, and iFi is making some well received smps available at different voltages for not a lot of money. But I am not sure that the smps hype from manufacturers is fully consistent with reality. Rob Watts of Chord insists that the switching supplies for their DACs can’t be improved. Experience of customers say otherwise. Theory meets reality at your ears. That is where I make my decisions.

Switch modes can be very quiet T&A uses them in one area of their excellent

200 dac , a top linear supply is better  90% of the time 

the downside is they are much larger , use much more power , but infused to operate the whole unit then LPS for sure. I use Linear Tube Audio , And a mojo audio both are one of the best out there.

I had a DC power cable that didn't fit well, so I ordered one from Monoprice and it worked perfectly.

Doesn't the Swagman have an IEC that accepts a standard power cable?
By "wall-wart" do you mean the DC power cable with the 2.1mm barrel connector that goes from LPS to Arcam?

I want to upgrade the sound I have. I just purchased a Swagman Labs Linear Power Supply on ebay for my Arcam DAC. The wall wart it came with is not factory and is just a small universal one with the correct voltage but it does not fit securely into the back of the arcam dac. I hope my sound will improve. The Dac is a bit lean right now but oh so open in highs and midrange. Arcam was one of the earlier companies to design dacs I think. Any suggestions guys? I am using a Schitt Asgar 2 headphone amp into nice Grado cans. When I play an analogue source like my nakamichi it is still better (fuller). I need the dac for my music on my phone.  
I can put an AM radio next to the usually poorly snubbed diodes of a big linear amplifier and hear things too, and usually much larger current spikes at 100/120Hz on the AC line.
I would be far far more concerned about the power quality on the DC end of a wall-wart that is highly unlikely to be designed for optimum noise rejection for audio equipment than radiated EMI or what goes back on the AC line, which at least, if you buy approved stuff, has to meet some standard.
I tried using my Oppo 105 direct to amp and found using a preamp much better

Then, I bought a LPS from Ebay + a Rhodium IEC with heavy gauge pure silver tail that attaches to the board, which alone was a huge improvement

I haven't gone back to my preamp since
Anybody here using an Innuos Zen Mini mk3 with a LPS other then the one they sell? 

@lowrider57 , email Bob to inquire. The Matrix DC cable doubled the benefit of the LPS, it's that good. I had him use 2.1mm Oyaide plugs on both ends with standard wiring using the center pin as positive.

VHAudio sells a V-Quad cable that you can DIY. I have 2 feet of it but I have yet to complete the project with a pair of 2.1mm plugs. 
Has anyone experience w/ linear power supply with Schiit Modi3 DAC?

According to one reviewer who gave a very positive review of the DAC said he tried other wall wart types and linear power supply with it and there was no difference in sound with the Schiit., That would definitely save me money if there is no improvement. Does anyone have a different experience w/ Schiit Modi3?
I'll be sure to stay away from my wall warts with a portable transistor AM radio. I have a wall wart for a DVD player plugged in my panamax conditioner with my other stereo components never had a problem. Just use what comes with your DAC if you can actually hear it make noise then by all means replace it but replacing it with a linear with never hearing any noise doesn't make sense. 
@c_avila1 , is the Cerious a custom cable? I don't see it on their website.
I don't know if there is a standard connection to a LPS, but the termination to the device is a standard 2.1mm.

Don't neglect the DC cable. It's just as important. The Cerious Matrix DC cable provided a surprising boost in sound quality.
Just go near any SMP with a portable AM radio tuned down low in the dial somewhere 5-8 hundred kilohertz where it’s quite turn up the volume make sure it’s not auto muting and see the noise it put out when you wave it around an SMP.
And this is radiated RF, it penetrates everything bar a Faraday cage, then also add what’s going back through the mains wiring of the house.
Many amp manufactures that use SMP's in their better higher end models they have linear supplies in them, think why??

Cheers George
The noise issue with switching supplies is primarily common-mode. Fitting a common-mode filter on the DC feed to a DAC would be sub-optimal, its best position is on the mains side. Anyone got example DACs with CM filters on their power inputs?
If not, buy a new DAC yours must be pretty old and junk since even cheap ones now have pretty good filters. In others words it's  placebo. Good modern DACs  work really well with whatever power supply they came with.
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I've lived in 8 residences in the last 20 years and never had or heard any hum. I've never noticed it with wall warts or linear in amps. This thread is about DACs and if a linear would improve or is it placebo so whether you use linear, switched that came with the DAC it doesn't  really matter since we don't  listen to those wires anyway their waveforms are filtered by the DAC. 

Power supply or transformer hum is harder to get rid of short of replacing the offending item or getting rid of the component.

No, not really.

Hum in a system could have several causes:
- DC offset
- ground differential
- bad capacitor 
- a fluorescent ballast on the same or another circuit
- a dimmer lighting switch on the same or different circuit
- poor grounding
- a poorly sealed transformer
- loose nut(s) on a transformer
. . . and more

In the three residences, I’ve lived in the past 20 years, hum has been completely eliminated each time depending on the cause. None of the cures included replacing any equipment at all. I’ve never had a LPS that caused a hum whatsoever. Each LPS significantly improved the SQ. They generated clean power.

The noise problem is due to the fact that linear power supplies have large transformers and other magnetic components that operate at the AC line frequency (50 Hz to 60 Hz). These line frequencies are audible, and we are all too familiar with the hum and buzz that audio products can produce. It is no secret that this noise is caused by the power supply, but few people understand why it can be so hard to eliminate. Most people think that hum is caused by conducted interference (AC ripple on the power supply rails), but this is rarely the case. Most AC hum is caused by magnetic interference, and this can be very hard to eliminate.

Anyway I wasn't referring to only LPS or power supply  in general  but any noise in the signal that can get to the speakers. Power supply or transformer hum is harder to get rid of short of replacing the offending item or getting rid of the component. 
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If you turn your system up with nothing playing and hear hum then you need to look for the culprit unless you're using tube amps sometimes they will have a small hum. Other than that a good DAC should filter any power supply noise out, nowadays even a cheap DAC should. 
Probably it is the question of combination of specific: DAC, LPS, home electricity and power supply design of other components (CD transport, amplifier, preamplifier)  .
It is hard to say what the audible difference is with my fabulous power supplies, but because they're simply so large and cool (compared to the wall warts anyway) I've decided they're better anyway...and a part of my humless system.
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I used MCRU LPS with my Chord 2qute.
The result was a very odd, unbalanced, not organic, unmusical sound.
I read a number of other people reported similar bad results with LPS.

Yes, there are more positive reviews about usage LPS with Chord DACs.
But my Chord 2qute sounded so horrible with MCRU LPS, so I don’t believe to these positive reviews at all.
I guess these people just try get positively anything they bought and changed in their systems.
I read in one of my father's old MSEE textbooks from the golden age of hifi in the 50's, that a block of iron or other magnetic material in proximity to a transformer will improve coupling action between the primary & secondary windings.

Thanks, @mkgus. This info gives me something to research.

SMPS  can be better depends on who makes it and what it's  in.


"Switching supplies are noisy."

"Linear power supplies are best for audio."

We disagree!

About 5 years ago, Benchmark stopped putting linear power supplies into our new products, and we replaced them with switching power supplies. We did this because linear supplies are too noisy. Yes, you read that correctly, linear supplies are noisy! A well-designed switching power supply can be much quieter than a linear supply.

I don’t know what VPI claims. I always go back to this quote from @dgarretson in another thread:

I read in one of my father's old MSEE textbooks from the golden age of hifi in the 50's, that a block of iron or other magnetic material in proximity to a transformer will improve coupling action between the primary & secondary windings.

 I also added a VPI brick on top of the LPS transformer. Seems to help smooth things out. Strange.
@mkgus,  what does VPI claim the benefits of the brick are when added to a power supply?

+1 @steakster 

Every LPS I've had experience with has improved upon the supplied stock SMPS. 

As I've moved up the LPS ladder: improved outcomes.

Moving from stock DC cables to custom DC cables: improved outcomes.

Isolating the LPS: improved outcomes.

Changing power cables to the LPS: changes in results and when paired with the right power cable > improved outcomes.

Feeding the LPS via a custom power supply / power conditioner: improved outcomes.

I'm afflicted with a preponderance of misfortune in improved outcomes. I should read more and listen less.
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Here’s some recent test data for linear power supplies.  Looks like no audible difference.  I was considering buying a Small Green Computer, but when I talked to the company they tried to sell me power supply magic that cost more than the server.  When I questioned the need for the power supply equipment, they reported Mac mini ports are noisy.  There is also little negative date about noisy usb and many professionals are using 2018 Mac mini’s for audio mixing.  I’m going to save my money and stick with my Mac Mini.
I have some great yet currently extinct power supplies for my Cambridge DAC and phono preamp..."Pangea P100s" supposedly designed by a smart person, and they are MUCH better than the wall warts they replaced...noise filtering, stable transformer based little gems.
I recently made some improvements to my front end which includes a linear power supply for my CD player and battery power for my tube preamp buffer. Things have never sounded so analog. Digital glare? What’s that? I also added a VPI brick on top of the LPS transformer. Seems to help smooth things out. Strange. 
Just a report back:

I bought a Teddy Pardo LPS for ,my Chord Qutest and it has made a very substantial positive impact.

More depth.
More layers of sound.
Fuller sound spectrum.
Deeper tones.
Greater separation.

Very dimensional and a true sonic upgrade. I am very pleased.
Ian, in your case the LPS Farad3 psu is one of the best in the market. An excellent choice is also theSMPS from SotM Sps 500 with a clean filtered PSU.
I have a Qutest as well. Started with the wall wart, switched to a battery, then got a Teddy Pardo LPS. The Teddy Pardo is amazing, and I've bettered it by using a deep cycle battery and pure sine wave inverter to get completly off the grid(for the backend of my system).
I'm using a TeraDak DC-30W LPS from Taiwan ($100++) for my Chord and it does the job; I hear the difference. 
My Exogal Comet DAC has an optional power supply and according to Exogal : It provides plenty of power to stretch out and render the highest highs, drive the deepest bass, and lets the Comet provide the richest, most authentic sound stage of any DAC on the market.
I went for it :  )
Mytek recommends it for the Brooklyn, but if it was an improvement, it wasn't quite worth the complexity. :)

I used MCRU LPS with my Chord 2qute.
The result was a very odd, unbalanced, not organic, unmusical sound.
As result I sold this LPS.
The Small Green Computer 5V LPS goes for $160 + shipping.
It does the job. Only potential negatives ... it does run hot (I keep mine on all the time), and the blue LED display is rather intense.  If you check out my system in the Virtual Systems section here on Audiogon, you'll see that I have the power supply facing the side of the cabinet it resides in to minimize the intensity of the LED display.  Overall I give it a thumbs up. 
chord insists not but i agree with you gents, i added a LPS to an old 2Qute dac and was improvement.  I have the qutest now also, small green good?  others?   would like to keep it under 200.   thanks 
I too have a Chord Qutest.
I replaced the stock power supply with a Small Green Computer 5V Linear Power Supply ... and yes agree that it makes for a worthwhile upgrade.
Have gone from supplied wallwart to battery to linear power supply with my DAC. Each time was a noticeable improvement.