I’ve came across a different type of USB noise reduction dongle, it is made by Holo Audio. This is active regeneration of USB power and USB signals, unlike using simple passive filters in audioquest jitterbug and iFi iSilencer3.0. I will be ordering one to try out on the ROCK to the Holo Spring DAC.
Below is how a conventional AudioQuest USB Jitterbug looks like (basically just LCR filters):
Yeah, it’s “similar” to the Uptone Regen and Iso Regen, and the Schiit Wyrd in that regard (regeneration of the USB waveform). However the Regen products also do USB impedance matching on the output which may be important in an individual’s system. I was less taken with the Uptone products on cost grounds: the Iso Regen is 3-4x the price of the Titanis (which I already owned) and then they guilt trip you into getting an LPS-1 to power it – nothing less will do right? – doubling your cost to £$700+.
Thanks @joel, can’t wait to try out once I get my hand on it. I guess there will some SQ improvement since I use direct connection from ROCK to Holo Spring DAC.
Those conventional USB filters like Jitterbug and iFi tend to ‘colour’ the sound to some degree, some like the ‘analogue’ signature but I don’t. It makes the music less engaging and seems to me there’s a roll off in the highs.
Those USB Regen like Uptone ISO Regen (I’ve tried) and Holo Audio Titanis don’t seem to effect the tonal quality but takes away the ‘layer’ and let the music simply ‘breathe’ through naturally. It don’t seem to correlate very well with technical aspects. Some DAC has already built-in a high quality USB input, some even have isolation too. I think those cheaper DAC will benefit more on SQ if they use USB Regen. Below is interesting test on ISO Regen.