Ross
500+ Head-Fier
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Thanks!lifatec toslink glass
Thanks!lifatec toslink glass
I do use Audirvana+. Regarding RFI, isn’t the galvanized USB input on the Qutest meant to clean up any noise from the laptop?
Absolutely agree. Tried 2qute which have same galvanic isolation as Qutest with simple usb cable then with Wireworld Starlight 7 usb then Wireworld + Ifi nano usb 3.0Apologies, the response was mainly for the original poster ayang02 and the other poster using the default midi tools in macOS.
And the ‘isolation’ in galvanic isolation is not isolation from noise but isolation of electrical current via a magnetic field in a transformer. if you are lucky it will give you maybe 40 or 50db noise attentuation across a certain frequency range. Low level noise in the signal will get transferred just like the signal is transferred, some high frequency noise is attenuated and other high frequency noise capacitatively couples across the windings. The better USB decrapifiers will do a lot better than this. There are many many fantastical assumptions about galvanic isolation on forums such as this and I think the misinterpretation of the word isolation Is where it comes from.
That's true for the 2Qute. Much less for the Qutest for whatever reason. I found the iFi iPurifier 3 improved clarity a lot on the 2Qute. Did nothing to Qutest.Absolutely agree. Tried 2qute which have same galvanic isolation as Qutest with simple usb cable then with Wireworld Starlight 7 usb then Wireworld + Ifi nano usb 3.0
2qute with simple usb cable is no comparison to Ifi nano usb 3.0 + Wireworld Starlight 7... With just simple cable it sound much less 3rd, much more fatiguing, less lively, less extension in bass and highs. I would imagine Just how much more it can improve with Sotm Usb Ultra...
Anyone who think that any chord dac is immune to usb problems is delusional... Better use Optical if you want to save money.
Very interesting. My dealer even said that Dave benefits greatly from these decrapifiers. I heard Dave, but it was with Optical input though.That's true for the 2Qute. Much less for the Qutest for whatever reason. I found the iFi iPurifier 3 improved clarity a lot on the 2Qute. Did nothing to Qutest.
It also depends on the noise level of your system I guess.
Very interesting. My dealer even said that Dave benefits greatly from these decrapifiers.
Why? You can just compare inside of the any chord dac vs complex usb decrapifier and easily see the difference. Good solutions cost a lot and takes more space which result in more expenses for casework. Nothing is perfect.Of course, it makes sense for him to tell you that..
But good solutions for what? What needs a 'solution'? As mentioned above the 2Qute vs Qutest, the latter already has very good power filtering, jitter rejection, ...Why? You can just compare inside of the any chord dac vs complex usb decrapifier and easily see the difference. Good solutions cost a lot and takes more space which result in more expenses for casework. Nothing is perfect.
Apologies, the response was mainly for the original poster ayang02 and the other poster using the default midi tools in macOS.
And the ‘isolation’ in galvanic isolation is not isolation from noise but isolation of electrical current via a magnetic field in a transformer. if you are lucky it will give you maybe 40 or 50db noise attentuation across a certain frequency range. Low level noise in the signal will get transferred just like the signal is transferred, some high frequency noise is attenuated and other high frequency noise capacitatively couples across the windings. The better USB decrapifiers will do a lot better than this. There are many many fantastical assumptions about galvanic isolation on forums such as this and I think the misinterpretation of the word isolation Is where it comes from.
Apologies, the response was mainly for the original poster ayang02 and the other poster using the default midi tools in macOS.
And the ‘isolation’ in galvanic isolation is not isolation from noise but isolation of electrical current via a magnetic field in a transformer. if you are lucky it will give you maybe 40 or 50db noise attentuation across a certain frequency range. Low level noise in the signal will get transferred just like the signal is transferred, some high frequency noise is attenuated and other high frequency noise capacitatively couples across the windings. The better USB decrapifiers will do a lot better than this. There are many many fantastical assumptions about galvanic isolation on forums such as this and I think the misinterpretation of the word isolation Is where it comes from.
I just don't understand why people would attach crazy audiophile gizmo stuff on something that is already properly engineered. At ~$1800, I'd expect it to..
But not so fast! I tried a Matrix X-SPDIF 2 which I took from another system which does have optical output, and tried it with a cheapie optical cable. Yes, optical sounds better with the Qutest than coax from either the Matrix or the Singxer, and quite noticeably so.
Any current recommendations for optical cables?
Qutest is isolated, and you are correct in that the term galvanic isolation historically implies transformers but actually does not mean solely transformers at all; however the actual implementation in Qutest is not via transformers, as the isolation via transformers is, as you state, inadequate. It is actually with high speed RF digital isolators; the reason I use the term galvanic isolation is simply that people are familiar with that term, and is de facto implied that it is completely isolated from low frequency noise - with completely seperate grounds - which this categorically is, plus effective isolation at RF, as the coupling capacitance from the USB to DAC is only 2pF in total across the isolating device. No competent designer in their right minds would employ transformer isolation, as this is inadequate.
Indeed, looking at the Wkipedia page for galvanic isolation we get:
"Galvanic isolation is a principle of isolating functional sections of electrical systems to prevent current flow; no direct conduction path is permitted.[1] Energy or information can still be exchanged between the sections by other means, such as capacitance, induction or electromagnetic waves, or by optical, acoustic or mechanical means.
Galvanic isolation is used where two or more electric circuits must communicate, but their grounds may be at different potentials. It is an effective method of breaking ground loops by preventing unwanted current from flowing between two units sharing a ground conductor. Galvanic isolation is also used for safety, preventing accidental current from reaching ground through a person's body."
The page then goes on to state the various ways of achieving galvanic isolation and these are: transformers, opto-isolators, capacitive, Hall effect and magnetoresistance. The isolation used in Qutest is similar to opto-isolation, but offers lower propagation delay, lower coupling capacitance, and better skew characteristics than opto-isolators; the process involves modulating an RF carrier in the GHz region, which is picked up internally by an RF receiver.
Surprisingly, the device I use has lower coupling capacitance than opto-couplers; but of course we still have a coupling capacitance of 2pF. That may not sound much, but at GHz frequencies it becomes significant. So to ameliorate that issue, extensive GHz isolation is performed with chip ferrites and capacitors designed for GHz isolation, so that Qutest is effectively isolated from DC to many GHz frequencies.
So you are fundamentally incorrect in suggesting that Qutest has only 40 or 50 dB of isolation; moreover USB devices will not improve the isolation, but will actually degrade overall performance as overall system RF noise levels will increase due to the unnecessary circuitry being added.