ultraRendu and Component Stacking

Due to lack of rack space, I currently have my ultraRendu and my Nucleus sitting on top of my Bryston BDA-3 DAC (photo below). The power supply for the ultraRendu is on the floor next to the rack.
Should I be concerned about EMI being transferred between components by this stacking arrangement, or am I being pointlessly paranoid? If need be, I can move the ultraRendu and the Nucleus onto the floor on either side of the DAC. Comments?

Current setup:

I wouldn’t give it a second thought unless you are in fact hearing something amiss.

No, everything works great. Not hearing any noise through the speakers, other than normal minute background hiss/hum with my ear pressed up against the speakers.


Hum… I doubt that’s from the ultraRendu, but it should not happen. A well set up system should be dead silent when music is not playing. Either power or (likely analog) cabling may be at fault.

I’ve always had a tiny bit of background noise, regardless of which components I happen to be in my system at the time. There’s a lot of computer and network gear in my office where the stereo is, so that might have something to do with it. With the preamp (ARC LS17SE) muted, the hiss goes away but the hum remains (my amp is a C-J Classic Sixty SE). All the components in the system have three wire power cords, so there might be some ground loop action going on. The background noise isn’t audible from my listening position - I have to put my ear right up against the speaker to hear it.


There is a very low volume normal background noise which may emit from your speakers. Had it with my Parasound setup. It’s quite a common deal. Some setups are quieter than others. My W4S setup is dead quiet, but unless your normal listening position is three inches from the speaker, I wouldn’t worry about it. Surf around on some of the general audio forums and you’ll see its fairly common.

I would image that your ARC LS17SE preamp is picking up stray EMF from the electrically noisy computer equipment.
I remember a friend’s system with an ARC SP9 and that was very sensitive to EMF.
Try turning off all the computer & networking equipment and see if that sorts it.

Such great gear should not have hiss or hum. My guess is that cable routing or grounding might be at fault. My last two iterations of speaker and headphone systems have been totally quiet, but it took a bit of attention to signal cables (balanced where possible), their routing, power cables (shielded, well separated from signal cables), and power management (Furman 15is).

I have a question, and sorry since it’s not related to the thread topic - since the Roon Nucleus can output audio via USB to a DAC, what’s the purpose of the ultraRendu? Does it perform the native audio output from Nucleus?


You may be right about the computer equipment. Unfortunately, I’m usually using the computer at the same time I’m listening to the stereo, so switching it off is not really an option. Both the preamp and amp are tube gear, so this might lead to a little higher noise floor as well.

Fernando, I have used shielded interconnects (some of them are balanced), paid close attention to the quality and routing of all other cables, and have a nice (PS Audio Dectet) power conditioner. It could be a grounding issue but that’s something I can’t easily address. I’m not concerned about the noise since as I said, it is extremely low level in nature and I can’t hear it from more than a couple inches from the speakers.

Huy, don’t worry - this thread got derailed from the start so we might as well discuss anything that you guys want to talk about! The DAC can be connected directly to the USB ports on the Nucleus, and this is indeed how I first configured the system. It works fine this way. But the Nucleus is built around an Intel NUC motherboard and as such the USB ports are standard computer gear and are not optimized for high end audio purposes.

If you read Roon’s Knowledge base article on audio quality https://kb.roonlabs.com/Sound_Quality, you’ll see that they don’t advise connecting a DAC directly to the server - they recommend having the server send data over the network to a streamer such as the ultraRendu (which has low noise USB ports) for optimum audio quality. I admit I was dubious about getting the ultraRendu, but after reading enough posts in forums about the improvement it made, I decided to try it. They’re right: the ultraRendu made a significant improvement in the audio quality in my system. I’ve been extremely pleased with it.


Now, try nucleus > opticalmodule > etherregen > ultrarendu > isoregen > Dac

You won’t believe it how great the sound will be!

Cheers and Happy New Year!


Jorge, that definitely sounds interesting. I had not considered a configuration like that. I will have to read up on the etherregen and the isoregen. But all that those components you suggest total over $1,200! Experimentation with something like that will have to wait a while - I’m tapped out at the moment after the holiday season (and I just got done adding a Teddy Pardo 7V power supply to my ultraRendu!).


Hi Jerry,

I understand. I’ve been also buying these wonderful products over the years :slight_smile:
If I may advice, start with the Etherregen. At 650 $ it was the most “bang for the buck” investment I ever did. I got first (before eR) an optical module connected to a Cisco 2960 (circa 50$ second hand; new were 700$) and this uplift the SQ of my uR to a level I could not imagine. Later with the eR, I don’t have words…