DACS that isolate well.

[beerandmusic]

I was wondering if anyone knows of an inexpensive DAC that pays special attention to isolating well, that also provides it's own 5V reference voltage for the usb, and that reclocks. I don't want to get into the debate whether noise matters or not....just looking for a few different models that do this well. I already heard that the D90 does not have galvanic isolation...and i don't know about the other 2 features I want (provide their own 5v ref and reclocks).

 

I know the Schiits unison advertises it does this (galvanic isolation, reclock/regenerate, and provide their own 5v reference)

 

Miska said that the Schiit bi-frost doesn't measure well suggesting the 192k samping rate is not good enough.

 

In another thread Barrows said there are many dacs that do these things well, but didn't offer any suggestions....I am just wondering if there are any that do these things well under $1k?

 

[beerandmusic]

THanks for sharing...it will take awhile for me do digest even a fraction of this.

 

I guess where I am "trying to go", is that I am stuck...

 

I want usb for functionality purposes, but I always "think" that any solution other than usb (enet,toslink,thumbdrive, even hdmi) sound better.  Objectivists are trying to convince me that usb noise is not a problem and that all competent dacs will pretty much sound the same, and that my thinking is likely just a problem with "level-matching". 

 

Leaving that aside for a moment, i know that the only inputs to a dac are the digital music, the 5v reference voltage, and noise.

 

Some engineers will suggest the digital music always arrives at the dac perfectly or maybe lose 1 bit every so many hours, and that even if you lose a bit, it will be a dropout or glitch, something easily recognizable, not like something just "sounds better".

 

Anyway, that makes me conclude that "noise" on the usb is the problem with why other methods sound better.

That leads me to think that I want something that isolates this "noise".

 

I don't really care how the dac isolates the noise, i just want a solution that markets that it isolates the noise.  When I saw that schiit now markets that they reclock and isolate, I don't recall seeing that in their marketing before, and i have had a gen5 usb before, so perhaps i just overlooked that marketing...anyway, so i guess what you are saying here is that they haven't done anything new since gen5 regarding usb isolation.

 

hmmmm....where am I going with this.

 

I guess I just want usb to sound as good as toslink, but i want usb for DSD.

 

Maybe it is just as the other site suggests that it is just a matter of properly "level-matching" and that it is just in my head or bias....but it seems so much obviously better.....just frustrating when everyone thinks you are crazy...maybe i am crazy (grin).

 

[beerandmusic]

oh and regard to reclocking, i just noticed that schiit used that term, and I thought it had to do with "regenerating" the perfect bits, thinking that it may be necessary for timing purposes. (in my mind i just picture the bits coming into a circuit and then the dac uses it's own clock to pass the bits on to its circuitry at a control point that it is managing).... I don't really understand why reclocking may or may not be necessary.  I believe your device "regenerates" the signal because it is trying to compensate for usb noise that may affect the digital music?...and my thinking IF it is necessary, then that should be a function of the dac...and when I saw that schiit advertising re-clocking, that i thought it was doing something similar to your solution.

 

Nothing personal, I really don't want to buy gadgets between the pc and the dac, I am willing to wait patiently for a dac that won't need such technology...as you know i have already waited over 5 years (smile).

[beerandmusic]

1 hour ago, Superdad said:

 

Wurth Ethernet transformer module and a standard digital isolator on the I2S lines.

 

In your quote above, did you mean the gen5 already had Wurth Ethernet transformer module and a standard digital isolator on the I2S lines, or that is a new feature of the unison?

 

Not that it matters, because i don't want to fork out for a yggi, and miska suggests the bifrost sampling rate is not high enough, so I am not going to look at schiits anymore...at least not any of their current offerings.

[beerandmusic]

1 hour ago, Superdad said:

You also mention wanting a DAC that "provides its own 5V reference." I am sure you mean one that does not rely on USB 5VBUS power for its input stage. But unless a DAC designer goes to the trouble and expense of building in an entirely separate power supply just for the USB>I2S input board (and I mean if not a separate power transformer, at least a dedicated transformer secondary, separate set of AC>DC rectifying diodes, and voltage regulators--all to keep a separate 0-volt/-VE "ground" reference), your requirement will be at odds with having digital isolator chips on the I2S lines after said USB input stage.

 

Regarding 5v reference, i probably misunderstood schiits marketing:::

Self-power by the DAC for the critical low-noise re-clocking and latching sections.

 

I thought that meant that they are providing their own voltage (assuming some type of regulators), to do the reclocking so they didn't need to rely on the 5v from the usb in case it had problems.  I guess i just have a wild imagination (grin)...again, thinking the purpose is to isolate the usb noise.