Using the ISO Regen with Phasure LUSH USB Cable

[Superdad]

Cool topic gents! (And @elcorso, it's good to see you about here more again.)

 

I'm typing on my phone so I'll be brief with a couple of comments:

a) the idea--and execution--of our USPCB A>B Adapter is to perfectly relay whatever USB waveforms it is given, passing them through without altering signal integrity at all.  Think of it simply as a circuit board extension of, typically, the output of the ISO REGEN.  That is really what it is.  4-layer PCB, microstrip trace impedance control, layers used for ground/shielding, even the pins of our male 'B' plug PCB-mount innovation taken into account.

 

b) If people enjoy/prefer a USB cable after the ISO REGEN, that is perfectly fine.  It just means they are preferring whatever alteration/effect that cable has on signal integrity and impedance match.  

 

c) Idealized SI (see our published eye-patterns) is just one of the goals of the ISO REGEN. The SQ contribution of the Crystek 575 is easily heard (and was compared during development) yet I doubt the eye-pattern would spotlight that.

 

d) It is possible that preserving perfect SI is not necessarily the very best thing for SQ.  Maybe starting with great signal integrity and isolation coming out of the ISO REGEN and then altering it in a deliberate way (something Peter--perhaps unlike other USB cable makers--may be doing intentionally) can result in something desirable.

 

e) It is important to keep in mind that the purpose and mechanism by which USB cables and hub-based regenerators work is in altering what goes on inside the DAC's USB input stage--specifically the PHY and processor.  Ground-plane noise and bounce, packet-data noise, excess spurious voltages generated (all ways of saying mostly

the same thing) can and do occur in the DAC's USB input.  And even digital isolators (so called "galvanic isolation") on the I2S output lines after the USB processor will pass along stuff that gets "baked into" the signal (John wrote a full technical explanation of how that happens).

Ultimately we hear this because of its effect on the DAC's master clock at the DAC chip's clock input pin.  That is measurable.  

 

My sample of @PeterSt's Lush cable gets delivered today, but I am on the other side of the country visiting my father with my teenage sons for the weekend. I'll try to take a listen next week.

One thing I wonder is if folks enjoy the effect of the Lush after the ISO REGEN, would a shorty version, (ala what a few other firms started producing in the wake of the original USB REGEN's massive success in 2015-16) sound better?  Or is there some aspect to the inductance/capacitance/impedance characteristic of the Lush that its effect is enhanced by the length?

I am open-minded as always.  

 

--Alex C.

[Superdad]

14 minutes ago, rickca said:

Alex, following is from Peter's Phasure forum post:

70cm is the shortest length which is mainly because of the somewhat odd bending capabilities of the cable;
At the "A" side of the cable (this is the PC side) the cable is made so that it can bend up and down - not sideways. At the "B" side (DAC side) it only bends side ways.
Both combined implies that you need a bit of length to go from the one device to the other.

 

Oh crap!  First I have seen this info. From this now I think I might know what the Lush is about and we may once again have a case of working privately with similar techniques on opposite sides of the world. This could impact a product we have had in the works for a while. 

I want to say this publicly before I ever touch @PeterSt's cable (it arrives at my door in California today while I am in North Carolina for the weekend.).

I will say or reveal nothing more on the topic of construction--and I certainly could be all wrong.  

But hmm...

[Superdad]

46 minutes ago, Guidof said:

@Superdad Have you had a chance to try your LUSH cable? Any impressions? Positioning?

Best regards,

Guido F.

 

Hi Guido:

No I have been too busy with production tasks--and with tilting at windmills over various mis-measurements and attacks...  

Hoping to give a listen to it this weekend.

Best,

--Alex

[Superdad]

2 hours ago, johndoe21ro said:

Alex, what about that LUSH cable? 

 

It is interesting.  Still getting used to it.  Quite different from the 1m Curious Cable that I have been using for close to 2 years.  

The Lush definitely needs more time.  But mainly I need more time to play around and listen.  Just too darn busy right now! Have to flash, test, build, kit, and ship over 150 ISO REGENs and ISO REGEN/UltraCap LPS-1 bundles next week.

[Superdad]

On 9/14/2017 at 8:42 AM, Doak said:

I experienced the same thing ..... at the beginning. 

Then after at least a month of use I tried the "Lush 1st" placement and now prefer that configuration. Go figure?!?!

 

Regardless of which order you settle on (I have tried both ways), the ISO REGEN and Lush together are a sonically lovely match!  Like many of you, I am getting the best SQ ever from this pairing. (But wow, the Lush sure benefits from a couple hundred hours of use.)

Bravo @PeterSt!  

I think I should send him an ISO REGEN next month so he can hear the synergy for himself. Yes I know he already has galvanic isolation at the input of his DAC in the form of his Silanna-based (as used in the ISO REGEN) Phisolator, but he could put our piece at the computer end.