USB Noise filter on R2R DAC ?

I’m not aware that an R2R DAC per se is any more noise resistant than any other DAC depending on whatever noise filtering is built into it as previously mentioned.  I’d at least try throwing something like an Optical Rendu in front of your DAC.  The only thing I’m gleaning from people with much more advanced streaming systems than mine is that incredible performance is possible and EVERYTHING matters.  

  I’m not sure if this is any help, but I purchased the USB DISRUPTOR to try with my Schiit Yiggy DAC. I had ZERO improvement, but I really wasn’t  experiencing an issue before. I just wanted to try based on a friend having a major improvement with a different brand DAC. I had no long term use for it so I gave it to him. I would guess that it’s based on a particular DAC’s ability to filter as mentioned above. One point of note was that the company contacted all purchasers by email and requested comment on how it performed what DAC brand we had. So hopefully you can get input from someone with your exact DAC or the manufacturer. Also based on my experience contact the manufacturer of the brand you’re considering and see if they know or offer a trial period.  I’m trying to give input but it’s a little lame. Regards , Mike B.

While dac may have optimized usb, vast majority of servers don't. Rendering or filtering needs to take place outside of server if this case, this via usb filter or streamer/usb renderer. IME, renderer/streamer superior to filters.

Which R2R DAC?

The R2R DAC I have is Holo Audio May L3 KTE. It’s USB receiver already has built-in isolation and regeneration, but the use of another USB isolator at the music server side improves sound quality further.

I briefly tested MSB Discrete using the same music server. It sounds better without USB isolator at the music server side, just plug MSB's external USB Isolator (connected to Discrete with dual optical) to the motherboard’s USB2 port directly.