Power supplies and cables - observations, considerations & commentary

[firedog]

This comment intrigued me! Not that there is anything wrong with the sentiments expressed here, in fact this would appear to be a an entirely sensible comment. However, this forum is full of comments along the lines of 'you need the best possible, cleanest power supply you can get in order to achieve the best sound quality from a microRendu'. On top of this, these has also been much comment about the very high performance potential of the UltraCap LPS-1. So based on a general read of this forum, maybe without thinking too hard about this technically, it would be very easy to reach the conclusion that the general consensus is that if you have a microRendu it should be powered by the UltraCap LPS-1, which in itself is needs a LPSU to keep mains noise down. Of course Paul Hynes has a reputation for producing very fine LPSU's. So could you hear the difference between a mR powered by Paul Hynes LPSU alone or one powered by Paul Hynes + UltraCap LPS-1? I would doubt it, but with the extreme emphasis that has been placed on the importance of clean power for the mR, it is hardly surprising that this kind of thought process prevails.

 

I understands Superdad's comments to mean that even the MeanWell wall wart he will supply (if asked) with the LPS-1 is pretty low noise into the AC, and with a fairly benign noise profile. So it will sound good.

 

The comments on this forum pretty much always push towards getting the most expensive, most tweaked out solutions possible.

 

At some point there is a big drop off of results for the dollar.

If you already put out the bucks for a superior PS like the SuperCap, the question needs to be asked how much extra SQ you are getting in YOUR system by investing more in it,and is that the most worthwhile place for you to spend on your system, and even if YOU will hear the difference in YOUR setup.

 

The answer isn't always yes.

[Confused]

.

 

The comments on this forum pretty much always push towards getting the most expensive, most tweaked out solutions possible.

 

At some point there is a big drop off of results for the dollar.

If you already put out the bucks for a superior PS like the SuperCap, the question needs to be asked how much extra SQ you are getting in YOUR system by investing more in it,and is that the most worthwhile place for you to spend on your system, and even if YOU will hear the difference in YOUR setup.

 

The answer isn't always yes.

 

Quite! I am trying to imagine how good a system, or indeed how good your ears and brain would need to be, to detect the difference between say a mR powered by a 'respectable' LPSU such as the Paul Hynes and a mR powered by the LPS-1. I would have thought the difference would be vanishingly small?

[barrows]

As an aside... Answer this question: Why does a better power supply make a µRendu perform better?

 

I would submit that the answer is: less noise in the power supply and ground planes, means cleaner power supply rails, ultimately, to the masterclock. And every clock performs better with clean supply rails. This means lower jitter. So, perhaps yes, that jitter is what matters here...

 

Believe me, when Crystek (manufacturer of high precision low phase noise clocks) produces the specifications for their various clock models, they are using a very, very clean power supply.

[lmitche]

Hand up here! I have isolation transformers on all my equipment except my amp which already has a floating ground switch. The transformers cost around $100 each and make a world of difference in sound quality. Combined with ethernet isolation transformers, most devices are isolated on the digital as well as the AC side.

 

I am waiting for the next generation of PSU and USB isolation devices to complete the job.

[Blake]

Fair enough. Do your measurements provide data for literally every single aspect of music/sound that can be perceived by humans? For example, did you measure the perceived "soundstage"?

[barrows]

Poor Amir. I suspect he does not quite understand how to apply the scientific method to an audio component. The Scientific method includes: observations (in our case, listening), theory (speculation as to cause of the observed effect), and then, proof (in our case, measurements). Even Bruno Putzeys, a very skilled audio engineer who designs first via measurements, admits that he then listens to the component, and if something sounds wrong, he then returns to the measurements to attempt to find the problem he observed through listening. Mr. Putzeys mentions that he sometimes has to find new ways of measuring components under development when he hears a problem his initial measurements did not show.

There is ample observed evidence of the µRendu increasing sonic performance vs. other devices. So the scientific task at hand would be to develop the measurements which prove what is responsible for the improved performance, and not applying relatively simplistic and incomplete measurements. Measuring jitter at very low levels is brought with problems, even the (likely) most experienced person at this, John Atkinson, repeatedly has remarked how difficult it can be to get a meaningful result, and the noise floor of standard laptops is likely not adequate to make such measurements when the DUT is at the limits of the technically possible performance (does one actually believe that a standard laptop has the performance necessary for this measurement, when the reason for the existence of the µRendu is to outperform a standard computer in the first place?).

[Confused]

As an aside... Answer this question: Why does a better power supply make a µRendu perform better?

 

I would submit that the answer is: less noise in the power supply and ground planes, means cleaner power supply rails, ultimately, to the masterclock. And every clock performs better with clean supply rails. This means lower jitter. So, perhaps yes, that jitter is what matters here...

 

Believe me, when Crystek (manufacturer of high precision low phase noise clocks) produces the specifications for their various clock models, they are using a very, very clean power supply.

A very good point I think! I have been trying to rationalise my own thoughts as to what to get to power my mR, but the question 'Why does a better power supply make a µRendu perform better?' has to be THE question. Maybe if the Sonore guys could provide some additional clarity / information with respect to this point it could provide some useful insight.

[Superdad]

I understands Superdad's comments to mean that even the MeanWell wall wart he will supply (if asked) with the LPS-1 is pretty low noise into the AC, and with a fairly benign noise profile. So it will sound good.

 

The comments on this forum pretty much always push towards getting the most expensive, most tweaked out solutions possible.

 

At some point there is a big drop off of results for the dollar.

If you already put out the bucks for a superior PS like the SuperCap, the question needs to be asked how much extra SQ you are getting in YOUR system by investing more in it,and is that the most worthwhile place for you to spend on your system, and even if YOU will hear the difference in YOUR setup.

 

The answer isn't always yes.

 

Discussion of our forthcoming UltraCap LPS-1 (production board order being released in a few days!) belongs over at the its thread. But since some continuing premature fixations about choice of "energizing" supply for our 100% galvanically isolated device have bled over to here, I'll paste a recent response comment of mine:

 

I have a feeling that everyone is going to find out that the problem with SMPS has more to do with leakage currents--now blocked by the LPS-1--and not much to do with the high frequency noise they kick back into the AC (which modern Level VI units--such as the Mean Well we include--spread over a broad and very high range to meet the emission standard). There is already more crap in your AC lines than these SMPS are putting in.

 

 

Now back to watching the fun with Amir…

[lmitche]

First thanks so much for your concern about my safety. You should know that prior to purchasing the isolation transformers I did a lot a research.

 

Here is one article suggesting the use of isolation transformers with SMPSes.

 

https://www.google.com/url?sa=t&source=web&rct=j&url=http://www.signaltransformer.com/sites/all/pdf/IsolationTransformers%2520Increase%2520Safety%2520of%2520Electronic%2520Systems.pdf&ved=0ahUKEwj3u_7diO_OAhVCtRoKHSOKBZ4QFggzMAM&usg=AFQjCNH-wQhQ7tRIa4QZQYvyfquINqWREg

 

But you can't always believe what you read on the internet, so I had a trip to one of the largest manufacturers of toroids and isolation transformers in the states to ask about safety. They manufacture the toroids used in many of the high end audio components made in the states. They also crank out isolation transformers all day long from very small, less than an inch in diameter, to huge four foot diameter isolation transformers used by power companies.

 

Much of their business is in hospitals where their transformers are used with computers in operating rooms and patient monitoring systems. These isolation transformers are mandated by US regulation. My bet is that most of those computers use a SMPS to power the computer.

 

They also manufacture isolation transformers used on boat docks to avoid tragedies where kids swimming around a dock inadvertently hit water conducting current to ground. These tragedies seem to happen annually in the US.

 

So after a two hour discussion with the owner of the company about safety I feel confident that the use of isolation transformers on my audio system is safe.

 

Lastly, I don't run my equipment with exposed PCBs as is commonly done on workbenchs used by engineers and repair technicians. I am sure that Tektronix knows what they are talking about in this environment.

 

Thanks again for your concern for my safety.

[JohnSwenson]

Quite! I am trying to imagine how good a system, or indeed how good your ears and brain would need to be, to detect the difference between say a mR powered by a 'respectable' LPSU such as the Paul Hynes and a mR powered by the LPS-1. I would have thought the difference would be vanishingly small?

 

There is not a simple answer to this.

 

It breaks down into two pieces: how can anything in the upstream USB device (source) affect the sound quality that comes out of the DAC and how can the USB output of the microRendu be impacted by the power supply feeding it.

 

The honest answer to the first is "nobody really knows". There have been a lot of hypothesis floating around for a long time but with very little hard proof as to what is really going on. Part of the problem is that nobody knows what to look for since this is all about human perception, every time anybody tries to figure out exactly what is changing in the electrical output from the DAC to change the human perception nothing worthwhile comes of it. It seems human perception varies a lot from person to person, and from day to day for a specific person.

 

The result is that all we have to go on is vague correlations found from random testing. It's maddening from an engineering standpoint, but that is the way it is right now.

 

A bunch of experiments I did over a period of many years show correlation between signal integrity (SI) of the USB signal feeding the DAC and perceived sound quality. As the SI improves the signal sounds more "real". This has not been universally true for all people and all DACs, but has been true in a large percentage of the space (DACs and people).

 

Thus the purpose of the microRendu is to produce the highest USB SI I know how to do. SI consists of several things, jitter, noise on the signal, well formed signal (lack of over shoots ringing etc) and proper rise and fall times.

 

The power feeding the electronic circuitry is a very important part of achieving that high SI. As Barrows mentioned the noise on the power rails can cause increased jitter from the oscillator, and can directly wind up on the output signal.

 

The noise on the power rails comes in two parts: the inherent noise of the last regulator, (that is the noise when powering a fixed resistor) and the noise generated by fluctuating load current. This latter is particularly important for digital devices because the current drawn by the load (the digital circuitry) varies radically all the time. How the power supply behaves when given these changing load currents is very important. This is measured by an impedance VS frequency plot.

 

The Power Delivery Network (PDN) of the microRendu has been optimized to have very low impedance for high frequencies and mid frequencies, but not low frequencies. This was a deliberate engineering tradeoff, an important factor in USB SI is the length of the cable, shorter cables (everything else being equal) have better SI. So the device was designed to be very small so it could fit behind a DAC and connect with a very short cable. The tradeoff was that there is nowhere near enough room in such a package for enough capacitance to give good low frequency PDN impedance.

 

Thus for best performance of the microRendu the external supply must have very good low frequency impedance. Higher frequency impedance and inherent noise also make a difference but not as much as the low frequency impedance. A longer power cable has much less effect on SQ than a longer USB cable so keeping the case small so it could use a very short USB cable was the best compromise we could make.

 

Then there is an entirely different reason for the PS driving the microRendu making a differences in SQ: leakage currents. I don't have time to describe this in this post (I have put a lot in other posts here on CA) but in a nutshell it is noise that flows in a loop through the mains, power supply, DC from the PS, through interconnects (analog cables, USB cables etc) to another box and then back through the PS of THAT box to the mains. This is NOT, I repeat NOT the "noise on the AC line" that everybody talks about, it is completely different, it is hard to grasp what it is and how it works, but it is there with ALL power supplies that connect to the AC mains. Different supplies have different amount and spectrum of this noise and every system is going to be different as to where this current flows. It is usually a fairly low level effect, but once most of the other issues are dealt with it is frequently The largest contributor to sound degradation.

 

Thus differing supplies can have different leakage current affects on a system, completely irrespective to anything having to do with the first part of this post. Thus you may find out that a supply with higher noise but lower leakage, can sound better than the lower noise higher leakage supply.

 

One major problem with specifying leakage current is that it forms loops, (which is why it is called a ground loop) it takes at least two supplies connected to the mains to form this, thus it is impossible to specify the leakage current of a specific supply, it HAS to be in relationship with another supply. That makes defining a number for a specific supply extremely difficult. (If you have more than two AC supplies it gets even more complicated)

 

I know, way more than you ever wanted to know, but that is the state of things. The conclusion is that it is going to be extremely difficult to pick between two supplies based on published specs. You have to listen, and preferably in your system.

 

John S.

[rlow]

I'm thinking about going with a Meridian Director USB DAC to join with my mRendu. However, the Director draws its power from USB, and apparently prefers a steady 5V to sound its best.

 

Was wondering if anyone knows the USB output power of the mRendu?

[Superdad]

I'm thinking about going with a Meridian Director USB DAC to join with my mRendu. However, the Director draws its power from USB, and apparently prefers a steady 5V to sound its best.

 

Was wondering if anyone knows the USB output power of the mRendu?

 

Yes, the MicroRendu provides ample and very quiet USB VBUS output for DACs that need it. The 5 volt/1 amp regulator it uses to do so is best in class, and it is supported by a good size, ultra-low ESR filter cap, etc.

[rlow]

Fantastic, thank you! I've only had my mRendu running for a couple days now (with DLNA), but so far with my meager DAC, very impressed...next up, Roon + Tidal and new DAC!

[Nikko1960]

Thanks Nikko,

 

I've had a reply from Paul and he states the SR3-7.5V can provide 3.3A continuous and 20A transient so it's fine for the Upton UltraCap.LPS-1.

 

I understand the SR3 takes a while to settle-in so the results out of the box are impressive with more to come.

 

Regards

 

Paul

 

Hi Paul

 

Did you order the SR3 in the end? We should compare notes as I think we're local. I live just outside of Calne and my kids go to school at West Lavington!

 

Nikko

[flummoxe]

Hi Paul

 

Did you order the SR3 in the end? We should compare notes as I think we're local. I live just outside of Calne and my kids go to school at West Lavington!

 

Nikko

 

 

Hi Nikko.............I'll PM you

[Confused]

 

I know, way more than you ever wanted to know, but that is the state of things. The conclusion is that it is going to be extremely difficult to pick between two supplies based on published specs. You have to listen, and preferably in your system.

 

John S.

Way more than I wanted to know? Actually, no, that was a fascinating and very enlightening post! Many thanks for sharing John!

[HumanMedia]

 

The Power Delivery Network (PDN) of the microRendu has been optimized to have very low impedance for high frequencies and mid frequencies, but not low frequencies. This was a deliberate engineering tradeoff, an important factor in USB SI is the length of the cable, shorter cables (everything else being equal) have better SI. So the device was designed to be very small so it could fit behind a DAC and connect with a very short cable. The tradeoff was that there is nowhere near enough room in such a package for enough capacitance to give good low frequency PDN impedance.

 

For those of us who definitely can't fit a microrendu via short connection to the DAC anyway, are there any plans for a larger 'macroRendu' with better low frequency PDN impedance?

 

(It might not make much difference to me as I am powering my microRendu with a JS-2 and my DAC with a separate JS-2. The USB connection between them is a 75cm Chord Silverplus USB. Yes it sounds great.)

[vortecjr]

For those of us who definitely can't fit a microrendu via short connection to the DAC anyway, are there any plans for a larger 'macroRendu' with better low frequency PDN impedance?

 

(It might not make much difference to me as I am powering my microRendu with a JS-2 and my DAC with a separate JS-2. The USB connection between them is a 75cm Chord Silverplus USB. Yes it sounds great.)

 

I wouldn't overthink this. I'm using a short USB cable so are a good portion of my customers.

[audiocrazy]

I got microRendu last week and very impressed with the results using iFi 9V PSU. I compared with PS Audio LANRover and MicroRendu is comparable to LANRover. However LANRover edges out microRendu in some case but overall they are neck to neck in performance in my system.

 

I believe if i feed microRendu with good LPSU then it can beat PS Audio LANRover.

 

So I'm considering JS-2 or Sonore Signature LPSU or Uptone UltraCap LPS-1. I've HDPlex on the way to get a flavor of LPSU but I really want a better PSU.

I know its been asked several time before. Can anybody opine on how does JS-2 compare with Sonore Signature LPSU?

 

Here is my signal chain

Synolog DS-1813+ NAS

Roon Server on Win10 (6 core CPU i7-5860K)

Intel NUC i5 (optimized PC running Roon Endpoint + HQPlayer) with Fidelizer Pro on Purist mode.

microRendu(HQPlayer NAA)

Oppo HA-1 DAC

ATI 6007 amp (on dedicated 30amp circuit)

Salk Soundscape SS8

I use Furman reference IT-20i Power conditioner on dedicated 30amp circuit with Furutech outlet.

[Nikko1960]

Can anybody opine on how does JS-2 compare with Sonore Signature LPSU?

 

 

You probably want to wait to ask this question until the LPS-1 is in the wild. The price difference between it and the alternatives you mention is significant.

[vortecjr]

I got microRendu last week and very impressed with the results using iFi 9V PSU. I compared with PS Audio LANRover and MicroRendu is comparable to LANRover. However LANRover edges out microRendu in some case but overall they are neck to neck in performance in my system.

 

I believe if i feed microRendu with good LPSU then it can beat PS Audio LANRover.

 

So I'm considering JS-2 or Sonore Signature LPSU or Uptone UltraCap LPS-1. I've HDPlex on the way to get a flavor of LPSU but I really want a better PSU.

I know its been asked several time before. Can anybody opine on how does JS-2 compare with Sonore Signature LPSU?

 

Here is my signal chain

Synolog DS-1813+ NAS

Roon Server on Win10 (6 core CPU i7-5860K)

Intel NUC i5 (optimized PC running Roon Endpoint + HQPlayer) with Fidelizer Pro on Purist mode.

microRendu(HQPlayer NAA)

Oppo HA-1 DAC

ATI 6007 amp (on dedicated 30amp circuit)

Salk Soundscape SS8

I use Furman reference IT-20i Power conditioner on dedicated 30amp circuit with Furutech outlet.

 

I think you going in the right direction and will get a better idea about things when you try the HD-Plex PS.

[jtrelin]

I'm using the mRendu with the Sonore signature and I'm very happy with it. It took me a while to realize how good it is.

 

I have found that it's as good as what's around it. Meaning, to me it doesn't appear to be a limiting factor in my system, which is a lot to say.

 

 

 

Sent from my VIVO XL using Computer Audiophile mobile app

[asdf1000]

Hi all,

 

Can anyone share any experiences/recommendations for good performing PSU's for the microrendu, that are up to half the value of the microrendu itself - I'm on a tight budget at the moment. The Paul Hynes is attractive but shipped to Australia is more than the price of the microrendu itself and I can't go there for the near term.

 

So approximately up to USD300, AUD400, or 250GBP is my budget (roughly half the price of the mR itself)

 

Here in Australia I've been reading some great reviews on the Geisler Audio linear PSU and the price is comfortably under half the price of the microrendu

 

Appreciate any opinions / experiences

 

:-)

[audiocrazy]

Hi all,

 

Can anyone share any experiences/recommendations for good performing PSU's for the microrendu, that are up to half the value of the microrendu itself - I'm on a tight budget at the moment. The Paul Hynes is attractive but shipped to Australia is more than the price of the microrendu itself and I can't go there for the near term.

 

So approximately up to USD300, AUD400, or 250GBP is my budget (roughly half the price of the mR itself)

 

Here in Australia I've been reading some great reviews on the Geisler Audio linear PSU and the price is comfortably under half the price of the microrendu

 

Appreciate any opinions / experiences

 

:-)

I recently added HDPlex 100W LPSU to my setup with mR. Its priced at $399 USD so not exactly half of mR but the performance is better than iFi in my setup using Roon+HQPlayer.

Not sure if you have it available in Australia.

I think mR performance keeps on getting better with a better LPSU.

Eventually I plan on upgrading it to a better PSU. Have not decided yet as I'm still waiting for Uptone Ultra Caps LPS-1.

[jjraffin]

Hi all,

 

Can anyone share any experiences/recommendations for good performing PSU's for the microrendu, that are up to half the value of the microrendu itself - I'm on a tight budget at the moment. The Paul Hynes is attractive but shipped to Australia is more than the price of the microrendu itself and I can't go there for the near term.

 

So approximately up to USD300, AUD400, or 250GBP is my budget (roughly half the price of the mR itself)

 

Here in Australia I've been reading some great reviews on the Geisler Audio linear PSU and the price is comfortably under half the price of the microrendu

 

Appreciate any opinions / experiences

 

:-)

 

I'm in Aus and happily using Clay Geiseler's power supply for my Rendu. But I can't say I've compared it with other models.

 

I will try with the LPS1 when it comes out.

 

 

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