MicroRendu, UltraRendu or Other

I have the Bluesound Node 2i and more recently added an ultraRendu (with UltraCap LPS-1).The Node 2i has a few functional advantages (such as support for integrating a hand-held IR remote, a greater variety of input/output options, and physical volume/tracking controls atop the device.) It’s a relatively user-friendly device.

For me, probably the most important thing the uR brings to the table is support for network operation of HQ Player. If you are not interested in HQ Player, then I’d hesitate to recommend the uR over the Node 2i solely on the basis of SQ. The uR (by itself) may or may not deliver a noticeable enough difference in SQ over the Node 2i (for you, in your system) to justify the additional cost. To know for sure, I think you’d need to try out both, then keep the one you prefer and return the other.

I know a lot about the pi processor board. I’m not against using it, but we looked at it and it can’t meet the goals we set forth for our products. I won’t get into why the pi board is inadequate for our needs because what we are doing in the Rendu series is proprietary. Hint, we are closely interfacing with the SolidRun module in a way that you can’t do with a pi board. The SolidRun module we use looks similar to the standard offering but it’s a custom order so your analysis is wrong. BTW we have our own processor board design, but it costs a lot of money to reproduce and it’s really not worth it for us to produce it because SolidRun has a firm handle on that.

FYI Some companies say ground up design but they are actually using reference designs made available to anyone so best to avoid assumption. Also, SotM claims to have made the operating system, but I know where they got it from…us:)

These are computers with USB output streaming bit perfect audio so irrelevant graphs showing nothing useful are pointless. I think’s it’s inappropriate for you to suggest we don’t have an incredible product with fantastic support and fantastic customer engagement. We are a small company in a niche market and we tailor to our customers. We have products at various prices with and without power suppiles.

By all means recommend Allo, SOtM, pi, or anything else for that matter, but please avoid comparing things incorrectly.


Tom, the UltraCap LPS-1 has a lot of noise on it’s output. The UltraCap’s charger was less noisy when I last measured it;) If you want to improve things you need a better power supply. At minimum you should implement a trick that John came up with to reduce the output noise from the LPS-1 which is to shunt the DC negative of the charger to AC ground. You can find more information on this technique here:

I thought the UltraCap LPS-1 came highly recommended. Now I’m confused. It has (or had?) a lot of noise, but now is less noisy? These are not inexpensive products. I’m not too inclined to mess around with the grounding.

@Jesus_Rodriguez, did you mean to say that SMPS are noisy ? The cited article by John details his experiments in suppressing leakage current from SMPS and concludes:

If you want to get it all you will have to use something like the LPS-1 which will get rid of it all.

The UltraCap LPS-1 was replaced with the UltraCap LPS-1.2. The UltraCap LPS-1.2 is an updated design and it also has the grounding trick built into the SMPS.

Both are noisy. The combined update and grounding trick on the LPS-1.2 makes for a cleaner power supply. Personally, I prefer a linear supply.

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So was John wrong in the cited article when he said the LPS-1 eliminated all such leakage current ?

I thought the design of the LPS-1 rendered the charging device completely irrelevant because there was never a connection between the charging device and the capacitor bank supplying power.

John identifies two forms of leakage current. The combination of the trick and the update design improves things.

I am more confused now. What I bought (to power the ultraRendu) is the LPS-1.2. Isn’t “LPS” an acronym for “linear power supply”?

Well this is what John says:

The PRIMARY purpose of the LPS-1.2 is to break leakage current induced ground loops, (which exist in almost all systems), and the fact that the output is isolated from the input (thus not affected by noise of the feeder supply) is a bonus, not a primary goal. Of course the LPS-1 has a very low noise, very low impedance output as well.
There are two very different mechanisms by which an AC power supply can interact through the AC mains:
1) traditional “noise injected back into the AC line.” This is easy to measure, easy to grasp what is happening, and many devices exist to try and filter out this sort of noise.

2) Leakage current, this is created by capacitances between the AC line and the DC output of the supply, it ALWAYS exists but varies from supply to supply. This is hard to measure, hard to grasp what it is and how it propagates through a system. After everything else is taken care of the leakage current is still there, I consider it to be one of the last great untouched detriments to obtaining best sound.

Both #1 and #2 exist in almost any system to varying degrees. Since there is already a large body of knowledge and products to deal with #1, I set out to work on finding ways to deal with #2. The LPS-1 is the first fruit of that work.

Leakage current has always been there, but has not been a big issue until recently for two reasons:
A) it is fairly low level in most systems so its effects have been masked by all the other problems preventing our systems from being their best, as these other sources of problems have been identified and addressed, the sonic results of the leakage current are now much more obvious.
B) leakage current from SMPS is usually much higher than from LPS, so the inclusion of computers (which are usually run from SMPS) into systems has greatly exacerbated the sonic detriment due to leakage current.

What are the two forms of leakage current you refer to ? Can you point me to where John discusses them ?

Above you posted that you had a UltraCap LPS-1 not an UltraCap LPS-1.2. The UltraCap LPS-1.2 is the updated design with a built in grounding trick in it’s charging supply.

An UltraCap is charged by a switching mode power supply connected to your AC mains. The unit has a switching bank of ultra caps driving the output.

I prefer a traditional linear power supply with no switching components.

The link above was provided to show the member how to shunt trip the noise from the DC output of the SMPS charging the UltraCap LPS-1 which otherwise sales right through the unit.

The link above was not provided to inform you about low impedance leakage current and high impedance leakage current.

I stand corrected on my assumption, thank you for taking the time to clarify.

So we agree not producing it is the smarter approach.

We agree on that.

Something useful might be that you, the designer, or any of the ownership at Sonore demonstrate that what you’re doing is audible, by publicly submitting yourselves to a blind listening test to silence the people who claim all you’re doing is spreading FUD to sell product. This isn’t limited to Sonore. I’d love to see it become a standard, especially in the “experimental computer science” space.

I was responding to a specific claim of interference due to size of the board, made by one of your customers. My claim stands, which is that the fundamental design is similar to the allo: compute board on custom silicon. The result is also audibly identical, until you, not “your happy customers” can prove otherwise.

[Moderated] I went out of my way to call your UltraRendu a “really nice, really clean design”, which I’m sure it is - I’m not sure what more you need. I’ll take your word that your support is top-notch, and stated as much in my closing paragraph. I’ve been on the receiving end of engaged your customers are in the past, and it was not pleasant, so can attest to that as well. Value is another matter, and highly personal. If someone wants to pay ten times the price of a pi, double what Allo charges, or a quarter of what dCS does for a device of comparable function, it is up to them.

I will, however, gladly confess that there are many reasons I would never suggest anyone buy one of your products. [Moderated].

We don’t make any outrageous claims about our products and simply state that using a better power supply gives you better results. We also state that the output is bit-perfect which is to say that we don’t alter the signals as some have claimed. I don’t have to guess about these things in a blind test because I can hook it up to my analyzer and measure the output of the DAC and prove it. These devices are connected via ground planes and cables so things like power supply noise matters. However, if you are going to use a good power supply then we owe it to you to make these units as low noise as possible. If my customers want to say they enjoy our products I don’t think it’s appropriate for you to shame them any more than its appropriate for you to shame them if they like some other product that you are promoting. I simply ask that you not make false claims. There is nothing experimental going on here. We make a microcomputer with low noise regulators and low noise oscillators run on custom software that we have developed over a Linux platform. The software is an integrated part of the design and maintained for the customer as opposed to a DIY project where the customer needs to maintain the software themselves. This kind of work takes a lot of time behinds the scenes and costs a lot of money so the price of our products has to reflect it.

On face value, things can appear similar. There is no collaboration between our companies so expect differences. I don’t have to prove anything to you. I also don’t have to discount happy customers who enjoy our products.

I know John personally and he is a very humble guy/genius. I appreciate and agree with you that the UltraRendu is a “really nice, really clean design” I have no issue with people buying what they want to buy.

You made some false claims and they needed to be corrected. It’s not personal.

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Of course, you can buy the updated ‘Charging Supply’ for the LPS 1.2 to use with the LPS 1 unit.
Cost £21 from https://www.vortexbox.co.uk/Uptone_75V_ground-shunt_36W_PSU/p317978_17832335.aspx for those in UK etc.

And here from Uptone Audio themselves, at $17 for the revised Supply https://uptoneaudio.com/products/uptone-branded-7-5v-4-8a-36w-smps-with-internal-ground-shunt (Ships worldwide via Priority Mail or FedEx for just $34 ($25 Canada; $9 USA);

Some would say the claim that using a better power supply and / or optical devices to isolate equipment results in audibly better sound is outrageous.

I was not aware of these claims, and naturally never made them myself. I’m sure we agree they’re idiotic, and would be trivial to disprove.

As we both know, a well designed and executed blind test has nothing to do with guessing. It is, however, intriguing that you state it would.

I will remind you of the trite “extraordinary claims require extraordinary evidence”, and that I am not the one claiming a bit is not a bit here.

Once again, this is not criticism that applies specifically to Sonore, and I would say the same, as far as USB is concerned, to SoTM, @wklie of Lumin, the @ALLO_audio_boards people, a USB cable manufacturer, or anyone else who makes similar claims. This is not to imply these devices have no other qualities, of course.

To reiterate: I am not the one claiming these devices make an audible difference. Hell, I doubt that a bit is a bit, and that PSUs make a difference, enough to use one of your competitors’ devices, and have said as much in this very thread.

I will also share that I am not a manufacturer, nor am I associated with one, but dare hope that if I was, I would not [Moderated] refer to a competitor’s measurements as “irrelevant”, all while refusing to provide my own with the associated protocols so that they might be independently reproductible and compared. As long as the protocols were provided, and I claimed my products were superior, I will admit I might go as far as publicly offering a comparison of my own offering with that of the competition.

It is absolutely not my place to tell you how to better run what is already a successful business, but I do believe sharing both those measurements and the protocols that would allow them to be replicated is something that would be of value to the entire field you operate in. Likewise, and this is also something I say without irony, I am looking forward to the long-promised device your designer has stated he was working on and that could be used to prove his intuitions. Evidence-based competition is good for everyone.

Instead of alleging, I would appreciate it if you show me where I have shamed your customers for enjoying your products.

The one thing you will find is me making a reference to a completely unacceptable use of language by one of your customers, in support of you, and against the people who do not blindly believe your claims.

Because I was curious where you could get such an idea from, I’ve just looked through my post history. The one thing that did stand out, apart from us disagreeing on expensive 9/12v cables, was that I’ve pointed towards your products (alongside those of SoTM, Allo, and others), multiple times.

The one thing where I have a small doubt is if you happen to also be involved in selling audiophile Ethernet switches or USB cards. I have called those idiot magnets and suited for the truly brain damaged, respectively.
Lest you start believing this is some type of cabal against an engineer you seem to admire, the device I linked and referred to when talking about Ethernet was sold by SoTM.

If there wasn’t, wouldn’t the science behind it, as applied to audio reproduction devices, be widely accepted by the scientific community and the subject of numerous awards in fields and publications much more prestigious and reputable than audiophilia and subjectivist audio publications ?
Despite how groundbreaking such an event would be for audiophiles everywhere, and the service it would do to the hobby, I would wager that outside a rather rarified group, the humble could maintain their humility. In fact, I’d assume a humble man would rather choose to start by getting that work published in a scholarly journal, rather than risk being exposed as a genius by people so technically incompetent they believe in the magical properties of special stones.

If such material exists, I would welcome a DOI or two, because I’m genuinely curious.

I’m sure Ropieee users are very impressed at self-updating software.

I agree you have nothing to prove to me. I also agree you shouldn’t discount happy customers who enjoy your products, but, unless you’re incapable of backing that claim up empirically, I don’t see how proving your products make a clearly demonstrable audible difference, with the most trained listener possible, yourself, would be discounting them. Unless, of course, they don’t do what you told your customers they do. Which, in case you didn’t know, is fix a problem that “translates into a minimizing of critical spatial or soundstage cues.”

Sonore offer a 30 day no questions asked return policy. Anyone can try their products at no risk, if you don’t think it sounds better than something else, just send it back, what could be easier? Trust your own ears as they say. If you don’t like their marketing claims, just move on, let go of the bone. An ultraRendu clearly sounded better than the NUC that I was using for MPD, it really was a no brainer. Similarly, using the ultraRendu in Roon Ready mode was demonstrably better than a MacBook Air running Roon Bridge. YMMV which is perfectly fine.

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You seem to assume I live in the US, which I don’t. Insured S&H both ways + taxes on an UltraRendu would cost a couple of hundred.

This isn’t the way it works. The marketing (including organic) leads to biased expectations. Given the extraordinary nature of the claims, psychology, including cost, makes this family of products (once again, not only by Sonore) especially likely to create such biased expectations. That’s fine, but it also puts the onus on any such company to first prove their claims. In the case of Sonore, this relatively simple request seems to be interpreted as desire to pick a fight, not something that signals high confidence, I’d add.

Then comes a degree of game theory: if there’s a small price differential over a DiY solution, alongside measurements, I’m ok with taking the risk of being taken for a ride, including through psychology, because the risk is low. YMMV, of course.

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They would be wrong and it’s very easy to show the noise at the output of the DAC.

I’m not getting the impression that you know anything about this topic.

You are saying extraordinary claims have been made. You can repeat it as often as you like and convince yourself that it’s true, but none have been made.

There must be a conspiracy if everyone is involved. So where else have you made these type of allegations and mocked the designers and developers of these other fine products.

One minute you are saying they don’t make a difference and another minute you are saying they do. According to the link you provided above there is noise originating from the computer and galvanic isolation is useful. Sounds familiar right.

I have a hard time believing you. You haven’t provided any evidence for your position and yet here you are making outrageous claims and pretending to be above us all. When you do say something wrong because you don’t have a clue or don’t bother to research it…at least you admit you are wrong. How many times have you been wrong now because it seems like a lot.

It’s really not your place, but you want to do it, and you are doing it. Why would I provide you measurements for the obvious. Besides you have already stated with conviction that what we do does not matter. You made up your mind nothing right.

You are wondering off topic and ranting about stones and magic. I said there was nothing experimental going on. The scientific community passed you by a long time ago. The topic of noise and galvanic isolation you suggest do not matter only to later say that they do are well understood.

Okay. Again you are wondering off topic.

You repeating yourself and I’m forced to do the same. I just don’t have the inclination to show you anything especially when it’s abundantly obvious.