review of the 5V "Kingrex MK2 PSU" used in USB
Mar 2, 2013 at 8:59 AM Post #32 of 41
Quote:
got pics?

sure
 


 
also these are said to be with silver plated contacts, but contacts are colored like copper or something so i dont know
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Mar 3, 2013 at 8:34 PM Post #33 of 41
Copper, lucky you! Plug contacts have to be copper because these are visible from the outside but cheap cables/adapters usually go ghetto on the inside, especially if their wires are moulded.
 
Same goes for supposedly solid silver cables that can easily end up being SPC at heart, but who wants to cut an expensive cable in two to find out 
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Anyway, try to A/B PSU's now that you've gotten used to the Kingrex 
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Jun 21, 2013 at 5:43 AM Post #34 of 41
Me thinks you are rather harsh with your assessment of the Pardo usb psu. Makes me wonder whether you gave it long enough burn-in. When i first got it i was suprised at the over the top HF response, thought it stood out too much from the rest of the audio spectrum and was too dry and analytical. A few hundred hours later and all was well. I currently have another well regarded 5v psu that i am trialing and to be fair, it sounds almost as good as the Pardo but at around half the cost. I asked the maker of the other psu what he thought of the Pardo outputting 5.5v and he said he thought it wouldn't cause any problems as it was within the accepted tolerances.
 
Anyway, just my thoughts and felt i needed to balance out the criticism.
 
Interesting thread by the way and a pity more people haven't got involved.
 
Jun 21, 2013 at 7:03 AM Post #35 of 41
Hi Alvin, good to hear from you 
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Yep, I guess 5.5V is "acceptable" but I use a $3K DAC and I would really hate frying its USB board due to overvoltage....I believe it was supposedly burned-in when I got it, its previous owner had let it run for weeks IIRC?
 
And I rest my case that a +5% voltage drop under load on a $400 PSU is not acceptable, discrete is so much better huh. Its oxidizing 2 pins connector that you are advised to unplug & replug a few times every few months was the icing on the cake for me, so much for "plug & forget".
 
Anyway, there is no question that a short Injector cable sounded far more balanced to my ears on the DP1 than the stock cable Pardo provides. This said, we all use different gear and have different tastes, the beauty of used equipment is that I sold it to you at no loss and you could do the same so no harm done as there's really only one way to find out how something will sound within our own home environment. Surely any USB PSU's performance will also change depending on the voltage regulator(linear/switched mode) your audio equipment uses.
 
You are running a LCD-2 rev1 IIRC that would supposedly be quite dark so I guess you might have some use for a bright sounding PSU?
 
BTW, I've found a very short A/B USB cable that would prolly do wonders instead of an A/B adapter, more on this ASAP.
 
Jun 21, 2013 at 12:20 PM Post #36 of 41
I have never found the LCD-2 rev1 dark and my hearing is sensitive to any gear that is over bright. I discarded the cable that Pardo supplied with the psu and had a custom cable made, therefore less connections. Not sure how your dac works but i only use the Pardo to energise the chipset, everything else in the dac is powered off it's own internal supply.
There is no harm done as you say as i think it is a competent psu and i doubt there would be any problems with the pins oxidising. In any case, one thing i do on a roughly three month interval is clean all connections on my system, just like all good audiophiles should
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I have a few more psus i would like to try but to be honest i don't think the differences are going to be huge.
 
Jun 21, 2013 at 8:32 PM Post #37 of 41
OK fair enough, I also don't find the vintage yamies dark even though many ppl claimed them to be....if anything, I find dynamics pretty shrill 
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what's the USB chip and 5V voltage controller in your DAC? I think I saw some high-res pics of the Stello U3 on a blog, I'll try to find out what its 5V VR is.
 
in the DP1, the USB PSU is used to convert from USB to I²S, the latter being directly fed to the dual-mono PCM1795 design and IME/moon6's owner the built-in Stello U3 is very sensitive to the power it's fed. I've tried half-a-dozen USB PSU's and they all sounded quite different to me.
 
For the record, the U3 is using two 3ppm discrete clocks(for 44.1 and 48kHz multiples) so of course the cleaner the power the better. I guess things might change if your DAC is using a single 50ppm clock with PLL-based clock synthesis.
 
I'm also in the process of having a USB controller modified with a 0.5ppm clock and high-grade caps because at the end of the day, the quality of the USB data signal also matters quite a bit IME: http://eda360insider.wordpress.com/2012/08/24/friday-video-eyeing-the-eye-of-5gbps-usb-3-0-signals-with-a-13ghz-digital-scope/
 
I recall an OEM USB3 PCI-E controller board manfacturer showing eye jitter patterns but this video talks a million words really.
 
Oct 25, 2013 at 6:08 PM Post #38 of 41
It's great to see our little 'cut-price Aqvox' idea catching on: I bet MikroTik have sold a ton of these handy critturs, and I know we see plenty of happy customers buying the 5V KingRex PSU II for this and similar applications. To be fair, Aqvox should really take the main credit for doing it first, but we did it cheapest!
 
We do a lot of auditions where customers compare single-wire USB cables up to around £100 with the injector cable/gender-changer and a £20 linear PSU and it's never a result for the mainstream cable manufacturer.
 
I notice that PPA have just announced a slightly different take on the power injector, which is about £15. I was going to snag a sample and play with it: anyone used it?
 
Dec 30, 2013 at 1:37 AM Post #39 of 41
I was hoping to get a little information about a PSU for my Eximus DP1... I've read the thread and it seems that the Kingrex is the all out winner. Do you think one needs a PSU for every USB DAC?
 

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