Comparing servers

I’m running a Sonic Transporter i5 and will be trying another server, also set up to run Roon.

Once the music and Roon info is loaded onto the new server can I switch back and forth between it and the STi5 by assigning which one I want to play next as Roon core or is there more to it than that?

Since you are familiar with sonicTransporter, the i7 is your obvious choice. Twice as powerful as Nucleus Plus, and about $1,000 cheaper. Plus flexibility for outside Roon.

Website does not show it, but pretty sure @agillis has them in stock

How many licenses do I need?

I think that switching licenses is not really feasible for some sort of A/B testing. If there is enough time to do the switching you should be fine. Else you need an additional license. For the case you have two licenses, you can also prepare a remote per core which allows for quick control over both cores but if you want to use the same endpoint with both cores, switching the endpoint connection between the cores may cost some time anyway. So this all depends largely on your setup and use case I guess.

The ST uses a Lumin U1 Mini as a streamer which runs a USB cable to the DAC. The new server runs a USB direct to the DAC so swapping cables will be quick. Does the license not go with the designation of which server is the core? Not sure how that works.

From your description, it sounds like an Innuos. If so, which one?

Forgot to add I’m using an iPad as a remote, everything else is hardwired.

You can migrate your license back and forth between the two Cores. The point I think @BlackJack was trying to make is that this isn’t a quick procedure. So if you are trying to A/B, you will have a good bit of time between playback, and lose your audio memory.

That said, the Core doesn’t have any SQ to itself. Either it has enough CPU to play to your endpoints without drops, or it doesn’t. Only real reason to look at a new Core system is if you need more CPU (e.g, for heavy DSP usage). But your ST i5 should already be plenty powerful.

Understand about the core requirements but this particular server I want to evaluate functions as a core, streamer and endpoint if I understand the Roon terminology. But you’re right–if there is a long delay switching licenses it’s a waste of time. That’s what I was trying to determine with my post.

We sell the sonicTransporter i9 now. it’s even faster then the i7 plus it has a optical network interface to connect directly to your Roon Ready streamer.

I can still build an i7 if somebody is interested. Contact me at

I have found it typically takes about 30 seconds to migrate from one core to another.

I have found that as long as the Roon core is on a dedicated box with a low latency OS such as a sonicTransporter or Roon Nucleus. The server does not make that much difference in sound.

What does make a big difference is how you connect to the DAC.

If you go directly from the server to the DAC with a USB cable you get a lot of noise from the server into the DAC.

It’s much better to use a network player such as an ultraRendu. This will give you much better sound from your DAC then a direct USB connection to a Roon server.


Is it available in Europe as well?

We ship all Small Green Computer products world wide.

I can vouch for this. I had a Bryston BDA-3 DAC directly connected to my Nucleus and thought it sounded fine, but I took a chance on a used ultraRendu network player and it made a nice improvement in the sound quality. It made a network player convert out of me - I wouldn’t want to go back to the direct connection to the server.


I agree. I have a Berkeley DAC and use a Berkeley Alpha USB between the Lumin U1 Mini and the DAC.

Evaluating between two cores can be done almost in real time. Connect to one core, start an album, connect to the other core (and deautorize the running core) and start the same album. Now you can almost instantly switch between cores since both cores keep on playing until the Roon license server kicks one of the two out. This has never happened to me in a time shorter then 10 to 20 minutes, most of the time even much longer. Long enough to be able to compare the differences in speed, snappiness, or if you want sound quality. I guess it can be as long as a day if you disconnect from the internet

Comparisons like this always surprise me.
Your cores are connecting to what? The same endpoint? Over network or USB?

If it’s the same endpoint over USB then you’re actually testing the quality of the USB on the machine which has little to do with Roon core. You’re not listening to the sound quality of the server but the sound quality of the USB interface. If that’s the model you want to run with then more power to you. But, it’s not the “best practice” Roon set-up either. This topic has already been discussed, in length, elsewhere.

But, I think the only way to provide a valid “server” test is same endpoint over network and keep the servers in another room. Then you’re truly isolating the server in a way that allows you to identify if the server (core) itself has any impact on sound quality. Otherwise you’re just testing USB and any USB attached to a PC motherboard is going to be noisy and not optimized for the task of audio.

And responses like this surprise me as well. My current server is connected to my LAN. My Lumin U1 Mini is connected to my LAN and runs a USB cable to a Berkeley Alpha USB. The server I want to compare is a not only a server but a streamer and endpoint. It will run the same USB cable to the same Berkeley Alpha USB. I thought I covered the set up in my earlier posts but apparently not sufficiently.

You did. It’s confusing though. What are you actually trying to test? Replacing the Lumin by plugging the core server directly into the Berkeley? Right now it appears your configuration is:
Core -wired-> Lumin U1 -usb-> Berkeley USB DAC
That’s the recommended configuration.

Now it sounds like what you want to test is:
Core -usb-> Berkeley USB DAC
and use two different Cores for your testing.

All fine and good. I’m just confused why you’d go away from the recommended configuration by removing the Lumin. Very interested in your findings though.

The server I’m going to compare with my existing setup doesn’t need the Lumin or, obviously, the ST i5. I’ll post the results in a few weeks assuming I can make a valid comparison.

I can understand the confusion. I want to compare my system as it is now with a a new server that also is a streamer and endpoint. So I wanted to know if it’s possible to switch back and forth between my STi5/Lumin and the new server while running Roon.