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In-iso-Regen’ - a final, for now, USB 'connection’. (plus, wrapping an Intona against RFI)

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This USB configuration has been in place in my system since November 2016, so I'm just catching up with this BLOG post, but I think there are a few things worth saying about it.


After fooling around with Regens and various USB cables, and with a lot of input from CA Forum experimenters reporting their experiences, last Fall I came to the conclusion that a galvanic isolator like the Intona, followed by a USB ‘cleaner’ like a Regen, and then the best short cable (Curious) I know of, was probably as good a USB connection as one is likely to get. A number of CA reporters found this or similar configurations to be their favorite. When I found a good deal on a used Intona isolator, I set out to complete my implementation.


Now, as I complete this writeup, the UpTone Audio “Iso Regen” is marching its last steps towards its public release, I feel vindicated in my ‘design’, and confident that my SQ is not too far behind Alex’s and John’s fine new device !



The six parts of my 'In-iso-Regen' USB connection:


* A Supra .7m USB cable from my Mac Mini to the Intona input. Nice, but nothing special. I don't consider this cable all that important to the sound of the entire 'connection’. It was available and is generally good quality. The +5v line is unnecessary and blocked by a little tape strip on the A connector. ***


* Intona ‘USB Isolator’ (the Standard version is fine with me, and I got mine used, so less expensive), I wrapped the circuit board in copper foil for RFI protection. *


* USB ‘hard’ adaptor (similar to UpTone supplied one). The Regen input is closely attached to the Intona output by this adaptor **. I got it online because it fit better in the tight spaces behind my Benchmark DAC, also was useful in my dual Regen experiment.


* Uptone Audio Regen - ‘Green’ version (I still like the sound of the original version, and don't think the the ground lift resistor in the ‘Amber' version is important in this isolated configuration) Managed to obtain a metal case for it (Thanks, Alex !), to protect from RFI.


* My DIY low noise LPS (adj. voltage, 1 amp) for the Regen (see previous BLOG post for description). Unfortunately in this configuration the power cable plug into the Regen is pretty cramped, but doable.


* Curious Cable 200mm "Regen Link" USB cable from Australia (also bought used for a savings) ***. Short, stiff, but oh, so transparent :)



Implementation details:


* Intona RFI upgrade: With a metal case for the Regen, I didn’t want to leave the Intona ‘out in the cold’, so I ordered some RFI blocking copper foil from eBay. After removing the Intona PC card by separating the halves of the plastic case, I insulated the bottom of it with bits of regular black electrical tape over the largish USB connector leads (trimmed short with nippers, and a little filing), then added a piece of packing tape over the entire bottom of the PCB. I built up a little (upside down, ‘U’ shaped) box from scribed and bent clear acetate to cover the lumpy top of the PCB, and taped it in place with transparent wrapping tape.


Now that all the circuitry was protected from shorts, I wrapped the ‘box’ with the copper tape. First one end got two complete warps of the copper, then the other end, and then the middle, gently smoothing the foil down with a fingernail. I cut two 2” x 2” pieces of foil for the ends and pushed the foil side into the protruding part of the two USB connector shields to guide my X-acto knife in cutting out the holes for them. I left a gap around the ‘Device’ (A) connecter shield, and made the ‘Host’ (B) connector hole undersize to have the copper wrap grounded to the shield there, and open on the other side. Make sure of no ground loops through the cable shield, otherwise the whole point of the Intona (Isolation) is lost ! I figure that if radio waves are going to induce a charge into my shield, then, like an antenna, that charge should be routed to ground IMNSHO.

The holes for the PCB hold-down screws are inaccessible now, but the wrapped PCB fits snugly enough inside the box that a small piece of foam is sufficient to hold it in place.



** Regen case support: I found a 2” x 4-1/2” piece of .090” ABS sheet to glue to the bottom of the Intona case (off-center to lineup w/ Regen) and cantilever out 3-1/2“, to support a small (1” x 1-1/2” x .090”) shim pad for the Regen. After applying Cramolin contact enhancer to all USB connectors, a piece of double-stick tape under the Regen, tucked it, the Hard Adaptor, and Intona solidly, and safely, in place together.



*** Cabling: My two USB devices are now combined in one physical unit, making connections with the two USB cables easier and cleaner. The Supra cable has a ’S’ shape, coming from the back of the Mini server (sitting to the left of the DAC), looping to the front, secured to the side of the Intona box with a Velcro strap, and curving 180° around to enter the front of the Intona, sitting on top of my DAC. The Curious ‘Regen Link’ is bent to a ‘U’ shape, to curve down from the back of the Regen, into the back of the DAC. Short and sweet :)



The Results (drum roll, please):

My total cost ran to about $385 (excluding an Uptone Amber set, now available). Not too bad considering, but limited to my experiences. As they say YMMV. Well, that is if, you attempt to replicate my experiment here :) It’ll be interesting to see how the new Iso Regen prices out. But, of course, you have to add in an LPS-1 to the package ! As a matter of fact, I am rushing to get this write up done and posted before Alex release his new toy. Bragging rights ? Nah… :)


After assembling all these parts, I was so pleased, I just wanted to listen to all my favorite music all over again ! You probably know that feeling, it is one of the reasons we are audiophiles :)


I found the most obvious SQ improvements in Redbook material, not all, but the better stuff. The differences are more subtle with Hi Res files. As I attempted to quantify the magnitude of SQ changes I feel as if the SQ improvements I perceived with the initial Regen has been increased by about 3x with this new USB connection configuration, and along the same veil-lifting lines. I’ll call that 3RE (Regen SQ Equivalences). This is my new attempt to quantify SQ changes at this level. Will it catch on ?? Nah… :)


What it comes down to is, color me a very happy camper :) !


Dave A


1) Intona and other parts laid out

2) wrapping the PCB box in copper foil

3) wrapping the ends with foil

4) ready for finial assembly

5) completed unit

6) my DIY LPSU for Regen (on power strip)

7) Curious 200mm USB(yellow), (blue/black) power leads, (gray) Supra USB

8) front of my digital source with USB upgrade



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Recommended Comments

Its a nice experiment, I did similar experiments with powering the USB 5v with battery package and a linear step down converter, and got some good results. Then I thought the Uptone LPS-1 ultra capacitor system is the way to go, but to clean the power for 400 dollars feeding a USB input which has a USB chip on the reciever side? umm, well. even if SQ changes a bit, I figured thats not the way to go, as the recieving DAC has a USB chip, mostly XMOS chips that guess what, recreate some of the USB garbage. So I looked around for USB to AES converter, and found Gustard U12, even not the perfect one, but its LPS, and with Intona between, and a custom solder of one small pin on the gustard to keep it powered all times (it doesnt draw usb current to power its unit), and cut 5v entirely.. With USB to AES converter we can ensure the DAC gets 0.1ppm crystal oscillator clock to feed the digital signal, and thats what we are after. Even with Regen on USB, that is still relying on the DACs internal clock going through the USB interface. bingo.. SQ opened up and got very detailed compared to usb and Intona to my DAC (I dont have regen to compare with). My Tascam ADC has unfortunately an "upgraded" SMPS which makes me measure the 50hz ripple from the switching PS, and currently Im implementing an external LPS to it similar to the one you have, but waiting for a 12v linear regulated DC board to arrive before project is done to start measuring.. With as good as it gets power 12v to my tascam (well I could go batteries offcourse), and I will for measures, I will start to measure the differences in the chain, with and without Intona, then Gustard, AES, SPDIF, COAX with and without intona with LPS, and battery to my Tascam ADC. Great work man, it confirms what we are saying that the SMPS from PC/MAC is garbage in audio world. Last 2c, when I play music, I disconnect my laptop SMPS from socket entirely as some SMPS's leak that damn switching frequency back to the power lines.. I dont have Oscilloscope but I saw a good youtube video of it. Atleast dont keep SMPS on the same socket rail as the audio equipment in your fuse box.

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Very cool Dave! Thanks for posting all that with the photos too. Best wishes, --Alex C.

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I don't know... in my experience I really find that shielding that close to the circuit board is actually a bad thing, it traps and reflects the internal noises.

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On 3/17/2017 at 3:10 AM, koblongata said:

I don't know... in my experience I really find that shielding that close to the circuit board is actually a bad thing, it traps and reflects the internal noises.


Oh, really ?  Could you please expand on that idea of trapping and reflecting radiated energy ?


Sorry to be so long in replying to your interesting comment, but shortly after you posted it, CA got 'upgraded' and all but one of my Blog comments were gone. Chris C. had to fix them, after more pressing problems were attended to (or not).


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