Need for Dedicated USB Card

[kilroy]

My USB chain now consists of PPA v2 USB card to SOtM tx-USBultra to ISO Regen to DAC. Two LPS-1s power the SOtM and ISO. USB cables vary from Curious, TWL, Dana, Vovox, PAD depending on my mood. The PPA is the oldest thing in the chain, there since I built the server. The other devices are recent. Haven't tried without the card just taking USB signal off the server motherboard.

 

Would the PPA card even provide a benefit (or a similar SOtM, JCAT, etc USB card) with all the devices that now follow it?

[mansr]

Probably not. The ISO Regen should render upstream components irrelevant.

[kilroy]

Not altogether. The tX makes a significant positive contribution to the sound, quite obvious if it's removed. A major function of the SOtm is to reclock the signal. PPA cards for the most part seem to be fairly standard cards with a clock added. So I can see how at least the SOtM and maybe the ISO make the PPA a moot point, at least in theory. The real test is to pull it and listen, which I have not yet got to.

[mansr]

3 minutes ago, kilroy said:

Not altogether. The tX makes a significant positive contribution to the sound, quite obvious if it's removed. A major function of the SOtm is to reclock the signal.

All these devices act as USB hubs, and all USB hubs have their own clock or, if you will, reclock the signal. What the DAC sees is the clock from the last such device in a chain.

[kilroy]

Ok thanks.

 

So back to the question.

[mansr]

As I said, the host USB interface shouldn't make a difference. Why don't just plug the cable into another port and see for yourself. If the PPA card is no different from the onboard ports, it's unlikely another card would improve anything.

[zackthedog]

Why don't you try moving your USB cable to one of the motherboard USB outputs?  :-)  It's unlikely to change any of your settings.  See if you miss it.

 

I use the SOtM USB card and with nothing else in the USB chain the improvement is pretty significant.  I don't know if adding the other devices would make it moot.

[kilroy]

Agree, that's the best way to go. Thanks guys.

[ElviaCaprice]

A modified SOtM txUSBexp card will be a huge improvement over the PPA.  You already have the sCLK-EX card in your Ultra only using one point.  You have three extra points on that card.  For a huge boost in SQ, I would modify your server mobo with two of the points/clocks and the txUSBexp.  You won't need the ISO Regen anymore after that.  It would just degrade the SQ.

 

I used a PPA v2 in the past with the ISO Regen.  There is no comparison to the SOtM sCLK-EX in my opinion.  Huge difference.

[mansr]

Any difference from such measures is dependent on the DAC. A perfect DAC wouldn't be affected at all. Two different terrible DACs will likely react differently. Bear this in mind when presented with anecdotes like the above.

[kilroy]

EC, not sure I follow. The tX is an enclosed unit, inside is the sCLK-EX card or some configuration of it.  How exactly are you saying to use the tX?

[ElviaCaprice]

13 minutes ago, kilroy said:

EC, not sure I follow. The tX is an enclosed unit, inside is the sCLK-EX card or some configuration of it.  How exactly are you saying to use the tX?

Yes, the sCLK-EX card resides inside the unit only using one of the four available points/clocks.  You could sell the ISO Regen and that would fund nearly half the upgrade I suggested.  Would be necessary to send the server/Ultra off to SOtM.  2 Week turn around once they receive it. 

The two clocks I would upgrade on your mobo, the system clock and LAN clock if you use it for steaming, if not, then the USB clock for a connected USB drive to the mobo.

[GUTB]

After replacing my Seasonic Platinum fanless PSU with a TeraDak 380W linear ATX, I tested my externally-powered PPA OCXO USB card against a motherboard USB port. The difference between them seemed closer than I remembered, but the PPA was still noticeably better. More definition (typically lower electronic hash/mud). I’m not running a USB isolator currently, part of the reason going with the PPA was to eliminate the need for USB conditioning. Also, I’d hate to interfere with the PPA’s huge custom OCXO unit.

 

Saying that audiophile USB interfaces don’t make a difference is demonstrably false in my experience.

[esldude]

I am curious about this clean the USB vs get a better DAC decision tree. 

 

I don't know the OP's DAC, but for the price of all this specialized USB chain of gizmos and related linear PSs one could throw a pretty good chunk of change at a better DAC.  A Chord or Benchmark or something which is rather impervious to the USB input plus has a darned nice clock inside already.  External clocks can't fix the internal clock. 

 

 

[GUTB]

33 minutes ago, esldude said:

I am curious about this clean the USB vs get a better DAC decision tree. 

 

I don't know the OP's DAC, but for the price of all this specialized USB chain of gizmos and related linear PSs one could throw a pretty good chunk of change at a better DAC.  A Chord or Benchmark or something which is rather impervious to the USB input plus has a darned nice clock inside already.  External clocks can't fix the internal clock. 

 

 

 

I don’t consider this to be a "choice". Cleaning up USB is really just a hidden cost of USB audio. But, spending on cleaning up USB becomes an investment because the gains will move to your next DAC.

[esldude]

19 minutes ago, GUTB said:

 

I don’t consider this to be a "choice". Cleaning up USB is really just a hidden cost of USB audio. But, spending on cleaning up USB becomes an investment because the gains will move to your next DAC.

So you are making the assumption all DACs are heavily effected.  

 

So is $500 DAC and $2000 of USB cleaning better than $2500 DAC and no cleaning?  I betting you'll say yes. 

[firedog]

When I was using a Mytek 192 I thought the USB devices made a small but noticeable improvement. Made the sound a bit cleaner, seemingly took away a lack of preciseness and made the sound more clean and precise. 

My present USB input is on a Kii Control which is galvanically isolated. So far I  haven't found USB devices to make a difference. 

[mourip]

I used a PPA USB card for a while but now use a Mutec 3+USB for my headphone setup. It gets you away from the USB input of your DAC but still allows you to use USB out from your PC.

 

Better yet, try a Focusrite Rednet 3 ethernet to SPDIF converter which gets you off the USB treadmill all together.

 

This is my experience using my ears, in my space, with my associated equipment. YMMV...

[mourip]

13 hours ago, mansr said:

Any difference from such measures is dependent on the DAC. A perfect DAC wouldn't be affected at all. Two different terrible DACs will likely react differently. Bear this in mind when presented with anecdotes like the above.

 

Perhaps it would be helpful for OP if you listed a few perfect DACs along with their price? My guess is that few of us could afford one if it existed so we are back to making what we have sound as good as it can. You are right that one needs to carefully weigh anecdotal evidence.