I bought a digital copy of November HiFi News, for the Qutest review.
I read the post a few pages back about HiFi News saying they swapped out the power supply. The review was actually quite difficult to follow. (I know some may disagree but here is what I thought.)
Quote:
"Before I go on to describe my experiences of the Qutest's sound quality, we have first to address the issue of its power supply. PM's lab testing showed the standard 'wall wart' PSU to suffuse the audio output with interference that disappeared when he substituted a smartphone charger. I followed suit with an ifi Micro iPower .. etc."
It appears they are saying that the Chord supplied adaptor, created measurable noise in the Qutest audio output. That was solved by using a smartphone charger. ... Seriously! A smartphone charger has less noise that the charger Chord supplies and recommends. ... I actually find that hard to believe. However please don't mistake me for a Chord employee or over-zealous supporter. If I thought something was wrong with a Chord product I would say. In fact I sometimes think I found something wrong, write about it, then have to correct myself. (I did it within the last few days in the Mojo thread, about the Mojo case.)
HiFi News do go on to suggest, was the supplied charger one that didn't make it through Chord QA procedures. (That's not too good a thing to say, is it.)
In fact have an iFi Nano iUSB 3.0 power supply on my Chord Hugo 2. (I bought it thinking to use it with Mojo, as a RFI free power supply, as Mojo has no Chord charger.) I can't hear any difference between it and the supplied Chord charger, with Hugo 2. I know Chord would say, use theirs, because theirs removes RFI. However iFi power supplies use military grade RFI removal - apparently. ... That doesn't mean there is no difference in chargers used, as to sound quality. Just means I can't hear any.
I actually thought Rob had designed RF filtering removal into the Hugo 2, on both data and power in. We started using the Audioquest Jitterbug on out Mojo, on the Mojo USB data line in. To remove noise from noisy computers. It seemed to work. I figured Rob decided it would be cool to implement the same thing in his DACs. Though it may well have already been implemented in other DACs. However Rob does say, he can't detect any difference between optical and USB on the Hugo 2.