This is a software issue present in the latest kernels. I’m working on an update that has a new kernel version where this situation is improved (again).
Wrt to the Pi 4 and quality: I can’t comment on noise etc, but the big advantage of the Pi 4 is the improved bandwidth because of the changed architecture wrt ethernet and USB (they don’t share the bus anymore).
i get clicks on >192k content using a 3b+ via USB. would this be better with an Pi 4?
yes it will.
That’s really great to hear 
Sorry if this has been asked before: I am running a Raspi 4 with Ropieee into my Devialet via USB (Roon core is on a Mac Mini i7 2018). The Raspi 4 is fed with the new Shanti LPS (great little thing BTW).
Would ist make sense at all to change to Allo‘s new Usbridge Signature? I don‘t quite see the advantage as the Usbridge still uses a Raspi 3. So somehow it has to separate ethernet/USB on the board, which is already done on the Raspi 4.
Thanks for any input!
The USBridge sold as a package is not based on the Raspberry Pi, it uses the Sparky SBC.
The USBridge Signature is Pi based though, which is what Paul mentioned. You can install Ropieee on it.
Raspberry Pi Compute, yes, but is that architecture similar to the Pi 3B(+)?
Thanks for the feedback!
Does then Sparky SBC have a separate Ethernet/USB port right from the start?
I may be misunderstanding you here, but the raspberry Pi’s have always had separate ports for USB and Ethernet. The Pi 2/3 however had the Ethernet and USB buses share an interrupt channel which historically could lead to some traffic congestion in some scenarios. This is something i have never ever experienced, at least not in the form of dropouts and interruptions in the audio over USB.
As for the original Allo USBridge it was a combination of a Sparky SBC (Single Board Computer) and the USBridge HAT:
The new USBridge Signature is a whole different creature however, it is a custom board with plenty of adaptations for an excellent USB environment. It does though, use a the Raspberry Pi Compute module for processing,. which is a Raspberry Pi sans connectors and power supply (etc) on a DIMM-stick. It seems unlikely that the architecture for the Compute moduile uses the same interrupt mapping as the Pi 2/3 when the whole I/O is separate from the module itself.
Thanks, Mikael, for clarifying things! I am not so into electronics/digital lingo, but that‘s exactly what I meant: that USB and Ethernet share the same bus so that heavy data flow might lead to some conflict. It‘s a pity that Allo didn‘t incorporate the compute module of the Raspi 4. I guess development of the Usbridge Sig started before Raspi 4 was available.
One last question: the Usbridge Sig is used much the same way as a Raspi 4 with Ropieee, correct?
Thanks!
RoPieee will support the Sig from day one, I’ve got one running over here 
Has anyone compared the Raspi 4/Ropieee with Usbridge Sig running Ropieee?
Unlike RPi2 and RPi3, CM3 supports PCM768kHz/DSD512 without issues (tested and confirmed by Allo).
Whats the USBridge Signature like? Have you got a case for it?
https://www.allo.com/sparky/usbridge-signature-player.html
Have a look, i was also curious but was unable to get a relevant quote from their online shop. (incl the Shanti PSU)
Thanks @Mikael_Ollars, I have been keeping an eye on the site, so not sure how I missed this! I am interested in upgrading from my current USBridge, but I would like to see reviews first and some measurements ideally. I quite like the case.
Sounds like we could have a case for the Allo USBridge Signature as early as next week. Exciting.
This is only true for usb output I guess? I2s over GPIOs Max dsd output will still be 128/256?
For the USBridge Sig’s USB output it is true.
For the stock CM3 board on it’s own, I don’t know enough about the standalone CM3 board.
You’d be better jumping on the official Raspberry forum and one of the RPi engineers will answer whatever you need.