Best (sane) choice to power micro/ultraRendu?

[davide256]

I've been powering my micro Rendu for the past year off the adjustable 9V tap (set to 7.5V) on an HDPlex LPS power supply.  I see in window shopping

that Sonore recommends 7V for both micro and ultra Rendu so I'm feeling pretty good about buying a better (quieter?) power supply that I can  use

for now with the micro and later make the upgrade to the ultra Rendu.  Has anyone compared the different flavors of power supply, if so for under $1K

what are your thoughts, advice?  Looking for comparisons please, not owner loyalty statements.

[davide256]

1 hour ago, m3lraaHnevetS said:

ask @vortecjr to look for a second hand Sonore Signature PS, should be able to get one for 1K one day...I compared this with mR 1.3 and uR against Sbooster, Ifi iPower, LPS-1 and Sonore Signature Rendu SE. Only the SE bettered the Signature PS. the rest was blown far away.

 

So try to get a Sonore Signature PS or save up for a SE would be my advise

 

I found this article echoed your experience but it does appear the off the shelf price of the signature PS is $1300. Interestingly enough its not listed for sale on Sonore's web site?

 

https://positive-feedback.com/audio-discourse/sonore-microrendu/

 

If you couldn't afford the  Sonore PS, the reviewer seemed to like this next best, wonder if anyone on the site has tried it...doesn't look like he had the Uptone supply or Sbooster. As always trying to spread those audio dollars as far as I can. If for example there's really little difference between the HDPlex  and others below $1K, that $1K gets me halfway to a Yggdrassil

 

https://ciaudio.com/product/vdc•7-mkii-upgrade-power-supply/

[davide256]

The current draw of the micro/ultraRendu isn't really that high, and the strength of the devices are the low component noise levels of the board. DAR posted a recent article

 

http://www.digitalaudioreview.net/2017/11/allos-59-boss-dac-is-a-super-tasty-delicious-pi-maker/

 

Halfway down the article he says

 

" Moreover, I’ve heard it from more than one DAC manufacturer that a USB receiver chip will engage additional layers of otherwise dormant circuitry when faced with a super-jittery incoming data stream. Circuitry that when engaged introduces more electrical noise to the system. "

 

and then says pretty much the same argument about Ethernet frame errors. So power supply quietness seems key for best performance, the question is what's the valid comparison metric to judge a power supply by and is there more than 1?

[davide256]

2 hours ago, sandyk said:

 

Basically, the key ingredients for a good power supply are very low noise over a wide bandwidth, and a very low output impedance over a wide bandwidth . They should also prevent voltage spikes from being generated at their output due to sudden load changes.

The original generic Positive and Negative supply voltage regulators such as the LM317/337 (adjustable) and 78xx/79xx  (fixed voltage ) don't have a wide enough bandwidth to prevent SMPS ripple at 25kHZ and higher,  and it's harmonics, from almost sailing right through to the output; although a choke ( inductor) at their input in combination with the voltage regulator's input capacitor can be used to markedly reduce the level getting through.

I think we have a failure to communicate, lets try again

 

from HDPlex website  the ripple voltage on the 200W LPS  " <3mv on 19VDC/12VDC/9V/5V output. "

 

On a 7v signal, how much less than 3mv does the ripple noise have to be to make a difference? Does the Teddy Pardo perform better?

[davide256]

3 hours ago, One and a half said:

The Teddy Pardo graph shows the lower freuqency 'spikes' centred on 50Hz, it's 3rd harmonic, 150Hz, and 250Hz. These spikes are from the front end diodes making their way through to the output. This tells me, there's no choke in the DC or AC input, so far from creating noise on the AC side, well, 'significant noise'... marketing.  A very crude choke would be to wrap an AC cable around a steel pipe  At the power we are dealing with here, the cable wouldn't heat up that significantly.

 

The amount of crud entering the AC line is dependant on the source impedance of the installation and the crud value. No one has set out what this should be as a standard, since it varies from second to second.  

 

Now, the logitech switchmode peaks is all at the lower frequencies. Time and again, CA members when changing power supplies to anything other than SMPS will remark their bass is improved. No wonder since the crud from the PSU is treated as signal by the amplifier, way out of time with the music.

Still, the noise levels are low, good to see the values in db, but maybe the scaling should be the other way around. Like the Amir fiasco, it depends on how the measurement is made, but if the same instrument and method is used, we're just looking at the relativity between each model, which is fair enough, s'pose.

 

Hmm, does analog amplification logic apply to a pure digital audio device? Put another way, is a 50hz noise spike  a "choppy" sea or a "calm" sea to sail on for a device that takes Ethernet frames in, processes them, and outputs coax/spdif/hdmi? Not saying it doesn't, but trying to get some sense of the model principles for PS noise interference with digital. I know that I have experienced 60hz audible interference from a bad wallwart PS on a switch upstream CAT6 connected to microRendu... kind of like all the low volume signal level information was put through a blender. But that seemed pretty extreme, the wallwart was audibly humming when I put my ear near it.

[davide256]

Just saw this review,  it was interesting as a "what does it sound like" comparison of ultraRendu vs SMS-200ultra

and for the LPS1 vs SPS 500 vs Paul Hynes SR7 power supplies.

 

https://audiobacon.net/2017/11/18/sotm-sms-200ultra-network-audio-player-sps-500-power-supply-review/

[davide256]

After thinking about it, the SPS-500 makes more sense for me to start with. It's adjustable voltage and can handle  the 12V/4A power draw for the Microzotl 2 preamp, I can swap it back and forth with the HDPlex for both MicroRendu and Zotl to see  where the biggest improvement gain occurs. And if it doesn't pan out, should be easy to resell.

[davide256]

SotM SPS-500 ordered this evening, got an immediate response from SoTM that it would be sent Fedex later in the day.  Will want to burn it in but hopefully by end of next week can share whether it panned out vs the HDPlex PS. @SpeedRacer , will be curious as to your experience after you have had time to play with the Teddy Pardo PS

[davide256]

SPS-500 arrived, running the Microzotl 2 off it now for burn in. So far I can say that it runs a lot cooler than the HDPlex... and that I had a moment of panic

 after turn on with 0V measured output until I realized the green "powered" indicator on the front is also a  relay switch 

 

Ouch! My ear just got whacked  by the big drum used in Braveheart/Mornay's Dream... yea I think there's more current available  here than in the HDPlex...

[davide256]

hmm, how to say this. I am underwhelmed at the difference  between the HDPlex and the SPS-500 at a first listen feeding the microRendu. I'm going to give this the benefit of the doubt, that the lack of improvement is due to limitations of the Gustard U12 asynch USB converter. Hopefully Schitt will come though with my back-ordered Eitr  end of next week and I can try again after it settles in. Life is a lot, lot better though using the SPS-500 with the Microzotl 2

[davide256]

9 hours ago, sandyk said:

 

Dave

I presume that the HDPlex is a Linear PSU ?

 The SPS500 appears to be a SMPS , judging by the wide AC voltage input range without a selector switch, and the .pdf which doesn't appear to give too much away, including output noise level.

If you have access to a DMM, try measuring for A.C. voltage between it's metal case and mains earth.

If you read a fairly high A.C. voltage, it will almost certainly be an SMPS in use, and possibly also benefit from the 0 volts being earthed, although I would first try something  like a 22 to 100 ohms resistor to earth instead initially, instead of a direct connection to mains earth to see if it improves. 

 

Alex

 

http://docs.sotm-audio.com/lib/exe/fetch.php?media=manuals:sps-500_user_guide_rev1.1.pdf

hmm, can try but the U12 has already given me fits where the DBS feature on the AQ cable  breaks 176/192 DAC coax synch yet works with iFi Nano for asynch USB to coax conversion... having to use Toslink with it. The DMM shows about 163 mv between ground and case, not sure if that matters. If its an SMPS, I'm not going to complain, the playback difference  powering Zotl 2 headphone/pre-amp is like switching from bookshelf to full size speakers.

[davide256]

This has gone in a bit of a different direction than I planned. The difference the SPS-500 makes powering the Microzotl 2 headphone/pre-amp is just too great from that of using the HDPlex to ignore or even contemplate going back to the HDPlex for comparison when the Eitr arrives. Even better, with the HDPlex 12 v tap freed up, i was able to use it with the Synology NAS, a cleaner and more irritant free result in sound. So will sit tight with the new configuration for a few months, until I've kicked the tires long enough to think about introducing and evaluating another change.

[davide256]

In the FWIW column,  I did eventually buy an LPS 1.2 as well as ISO Regen. The LPS 1.2 within its current limitations is a better PS than than SoTM SPS500 for ISO Regen and/or microRendu. While I did not find power supply for the FMC to matter much, using a Netgear switch powered off the 12V tap of the SPS500 was noticeably better as a buffer between microRendu and rest of network... I use that instead of bothering with FMC's