Ideally Mike I want to get an honest comparison between to the 2 project streamers.
Is the £400 extra justified? Yes the S2 ultra is the preferred choice but just keen to see if anyone has done a like for like comparison. My understanding is the main difference is the usb dac out outout is isolated but not sure exactly on the key differences.between the 2 units.
As is often said as you move further up market you pay twice the price for a 10% performance improvement. My ears are also just over the 50 year mark and I do not hear the differences that some people here. But can you get them on trial to test for a couple of weeks, and then blow your budget!!
Personally I am waiting for the Matrix Audio Mini-i Pro 3 to become Roon certified as I have my eyes on that 
Mike
The Chord itself cleans up any USB signals incoming, so I wouldn’t put too much emphasis on that. Chord’s Rob Watts recommends using toslink optical anyway.
Thanks Dan. I’d forgotten about that so maybe the standard box would be ok. It’s not Roon ready/certified - is this a big issue ?
Adam
Likewise, nice to talk. Sorry, I haven’t heard the standard S2.
The Ultra is designed around the CM3 industrial version of the RPi3. Basically the CPU, you design the input and output stages, also the power side of things. Pro-ject employed John Westlake to do the Ultra design work. I don’t know if he was involved in the S2 but suspect not.
If you want bang for buck it would be USBridge Sig with Shanti. Notwithstanding the comments about the TT preferring other non-USB.inouts, about which I can’t comment (as in don’t know).
If you got USBridge Sig and Shanti pay attention to earthing as per the review. It makes a slight difference (worthwhile tho as costs nothing).
Phil
I’m a little to the party nonetheless here a few suggestions:
A used Squeezebox/Logitech Touch
A microRendu
I have and use both of the above and they both work great although the stock Touch does not have USB output and the microRendu only has USB output. The microRendu is Roon Ready but the Touch is not (although the Touch does work, i.e. is a Roon endpoint, with Roon).
Thanks Ralph. Shall investigate.
Thanks Phil
This was the unit I was referring to. Apologies it’s from.a dealers page but gives an idea… it might have preceded the ultra ?
Here’s a list of Pro-ject’s stuff that is compatible with Roon (“Roon Ready”). See the box you want on it ? You’re golden.
Don’t or want alternatives ? Have a look at this page right here. Remember: you want something that’s “Roon Ready”, not “Roon Tested”.
No that came after the Ultra. If you have a look on UK Distributor Henley Audio’s site that one still has a ‘new’ sticker on it.
I have a Chord TT2 and I use a Microrendu. I also have an EtherRegen upstream of the Microrendu, but some would argue that’s overkill. I am very happy with this setup.
Marco - did you purchase the power supply or what did you do ? I notice that’s extra depending on requirement.
I bought the microrendu in may 2016. It came with an IFI power supply any the time. Since then I have upgraded to an Uptone Audio JS-2 linear power supply
Just to add some perspective. The Microrendu with a “good quality” but inexpensive wall wart like the IFI was a revelation. (an IFI 9v is about 50$ on Amazon) Back then I drove a Chord TT directly from the USB output of a Mac and when I switched to the Microrendu the difference in overall sound quality was a “wow” moment. Some time later I succumbed to the upgrade bug and bought the expensive linear power supply. I’m convinced things improved further but it really wasn’t a life changer.
That’s interesting Marco. I also notice that the IFI is 9v so it might work with the Allo USB signature which I’m considering. Not sure unless anyone knows ? Thanks
microRendu’s are not wireless. Neither are the Allo USB Signatures. While you can add an extra WiFi dongle to it, I think. But, I am pretty sure that it will not be auto recognized so you might have to install the linux drivers. I would definitely ask the tech support of whatever you decide to get before getting it.
Mircorendu works off ethernet. If wireless is needed I would look for an all-in-one solution, for sure. Can’t help there
Thanks Dan that was going to be my next question. It does say that WiFi usb port but guessing driver dependent. Need to find out.
Wireless?
I use a simple Raspberry Pi 3B+, connected via WiFi to my Core. No dongle. Then USB out to my DAC. No Allo hat, just use the USB port. I’m running RoPieee on it. And it’s sublime, a truly ethereal experience even without Ethernet! But there are measurements of it, as well:
The iFi £50 supply can be had with different voltages. RPi needs 5V. DO NOT use it with 9V, it will blow the RPi or the HAT, or both. I know 