AQVOX low noise linear USB power supply for DACs ~$150 USD

wdmoore451 · « **Reply #60 on:** 1 Sep 2011, 01:17 am »

I purchased the AQVOX in early August and it arrived about 10 days ago. I plugged it in and gave it a listen that night, but did not hear any discernable difference in sound quality. If anything, it sounded a bit less detailed than I was used to and the imaging was fuzzy lacked solidity.

We were busy for the next several days so I left the AQVOX and the DAC powered on to see if it just needed some time break in time.

When I sat down to listen to it again last night, I was stunned by the improvement in sound quality. I experienced what other listeners have discussed in earlier posts. I am running a BAT-VK55SE amplifier, an ARC LS26 Preamp, A Tranquility DAC SE, a mac mini/Pure Music digital source, Magnepan 1.7's and a mix of relatively high end interconnects, speaker and power cables, so I had been pleased with the sound quality that I was getting. But with the AQVOX another layer of detail emerged -- not small subtle details but a significant change in the character of the music. In addition, the imaging was much sharper -- instruments and voices stood out in stark, dimensional relief from the background sounds. The bass also had increased definition and punch. All of this emerged from backdrop that was noticeably quieter than it had been before.

I have no idea how or why the AQVOX works, but there was a clear difference in the sound quality when using it. I recently upgraded to Audioquest Sky Cables from some entry level Transparent Audio cables. The difference when using the AQVOX was similar to the improvement from the cable change, but even a bit more dramatic.

I would highly recommend that anyone using a Tranquility give this tweak a try. It may have the same impact with other DACs as well -- I would be interested to hear comments from users of other DAC's who have used the AQVOX.

Dracule1 · « **Reply #61 on:** 1 Sep 2011, 02:31 am »

We have three fans of the AQVOX so far

. As I and others have said, the improvement in sound is better than any cable change I have ever experienced (and I have tried cables costing thousands). Anyone who doesn't want to spend peanuts (at least in audiophile money) for this is truly missing out. I am going to try it out on my $6000 reference tube DAC and see if there's significant improvement.

ted_b · « **Reply #62 on:** 1 Sep 2011, 10:32 pm »

Quote from: Audioclyde on 31 Aug 2011, 04:56 pm

On another note, and at the risk of further highjacking this thread, do you know if the Stello U3 will allow PM to run in integer mode (assuming the attached DAC can do so)?

Randy

My Stello U3 arrived, and yes it fully supports PM's nonmixable integer streams. It is an XMOS USB 2.0 device, and Rob was not surprised it was capable of integer support; he said all XMOS units were so far.

gooberdude · « **Reply #63 on:** 1 Sep 2011, 10:51 pm »

Hopefully after a few weeks more people will try this out. Dave at PI Audio ordered one too.

It'll be interesting to see which dac's thrive on the psu, and which ones do as well (or better possibly) using only the 3 headed dual conduit type usb cables.

Just 1 guys opinion but i'd rather have just a funky usb cable, rather than a psu (2/difft transformers) and a nice usb cable. But i'll take what i got, happy as a pig in slop right now.

It would be slick if PM or other software had a function that turned off the current from the computer to the dac, after the handshake. This might simplify things.

I have to agree with Dracule1 on the effectiveness of the aqvox. I'm a tweaker & not ashamed of it. This gizmo elicits a big change in the presentation, imaging & bass. Tried the EVS enhancers or diy version? Its like that, but waaaaay better. And my unit did take a bit to break in, which was audible & fun. During the first few hrs it changed, but has been as it is for a few days.

Audioclyde · « **Reply #64 on:** 1 Sep 2011, 11:01 pm »

I've started an order for one also, waiting on their response back.

I suspect I'm going to end up canceling my order for the Revelation Audio dual conduit cable anyway, as it hasn't arrived from Florida after 10 days and my 'seller' has failed to respond to my emails. I starting to suspect that this is another one of the guy's 'girlfriend' accts on Agon--with a little research on the net you can find that this seems to have been his common practice over the past few years. I will give it thru the weekend and then likely have to start my first ever Paypal dispute. I paid with cc, so I don't know if I should get them involved before notifying Paypal or after.

highfilter · « **Reply #65 on:** 2 Sep 2011, 12:10 am »

Quote from: Audioclyde on 1 Sep 2011, 11:01 pm

I've started an order for one also, waiting on their response back.

I suspect I'm going to end up canceling my order for the Revelation Audio dual conduit cable anyway, as it hasn't arrived from Florida after 10 days and my 'seller' has failed to respond to my emails. I starting to suspect that this is another one of the guy's 'girlfriend' accts on Agon--with a little research on the net you can find that this seems to have been his common practice over the past few years. I will give it thru the weekend and then likely have to start my first ever Paypal dispute. I paid with cc, so I don't know if I should get them involved before notifying Paypal or after.

I would notify PayPal asap when you know it was a scam. They've sorted out quite a few things for my friends when things went south in the past.

My AQVOX shipped a few days ago so I'll report back when it arrives too.

ted_b · « **Reply #66 on:** 2 Sep 2011, 12:31 am »

Quote from: Audioclyde on 1 Sep 2011, 11:01 pm

I've started an order for one also, waiting on their response back.

I suspect I'm going to end up canceling my order for the Revelation Audio dual conduit cable anyway, as it hasn't arrived from Florida after 10 days and my 'seller' has failed to respond to my emails. I starting to suspect that this is another one of the guy's 'girlfriend' accts on Agon--with a little research on the net you can find that this seems to have been his common practice over the past few years. I will give it thru the weekend and then likely have to start my first ever Paypal dispute. I paid with cc, so I don't know if I should get them involved before notifying Paypal or after.

I'm really sorry to hear that. Brad has been in constant contact with me (email replies usually the same day) and today just responded to some questions I had.
"A design change has come to our attention, necessitated by the fact that our previous revision does not function with some certain equipment. So please do simply return the cable you have to the PO Box address, and please allow me to send you a new replacement cable with my most heartfelt apologies for the inconveniences this has caused."

So I will continue to eval the dual conduit cable (cuz it sounds very good when it works), but I would caution, as I did above (with the Tranquility) against pulling the power cable nonchalantly unless you know the DAC or USB receiver chip can handle it.

roscoeiii · « **Reply #67 on:** 2 Sep 2011, 12:55 am »

OT a bit, but ted_b we will also be curious to hear how the U3 affects your Zodiac. Do you get the same improvements that Srajan reports?

ted_b · « **Reply #68 on:** 2 Sep 2011, 12:59 am »

Quote from: roscoeiii on 2 Sep 2011, 12:55 am

OT a bit, but ted_b we will also be curious to hear how the U3 affects your Zodiac. Do you get the same improvements that Srajan reports?

I will definitely report back (in a new thread) Srajan let the u3 run for 10 days before reporting; although I have the same break-in philosophy he does I'm not sure I have the patience.

Audioclyde · « **Reply #69 on:** 6 Sep 2011, 06:57 pm »

My AQVOX should arrive in a few more days; can't wait to give it a try.

On another note, my dual conduit USB cable arrived today, so I will be giving it a try tonight. Haven't heard back from Eric at dBAudio yet, so initially I will be leaving the pwr leg attached.

ted_b · « **Reply #70 on:** 6 Sep 2011, 07:05 pm »

Yes, leave the power leg attached cuz removing it breaks ground. If the Tranquility is needing ground (as many DACs do) then it will not work (or worse, be looking for ground from the 120v power supply). Not sure what the USB receiver would do in that case.

I'm having Brad redesign mine to include ground on the signal side so DACs that look for ground can have it unbroken should I want to pull the power (5V+). I also think some DACs look for 5V+ to do the handshake, but I could be wrong.

Also, Audioclyde give it a few days of settling in. I'm anxious to hear your feedback.

I'm beginning to think the best approach would be a single cable with everything but 5V+, then an AQVOX (if DAC needs it).

ebag4 · « **Reply #71 on:** 8 Sep 2011, 05:06 pm »

Gents,
I am currently running a battery powered Alix into a base Tranquility DAC. With the Alix being battery powered do you believe I would still hear an improvement with the AQVOX?

I dont know if the 5V output of the Alix's USB is any cleaner running on battery than it would be powered from the grid.

Opinions?

Thanks,
Ed

ServerAdmin · « **Reply #72 on:** 9 Sep 2011, 02:01 am »

Please keep review threads on the topic of the item being reviewed. Thanks.

ebag4 · « **Reply #73 on:** 9 Sep 2011, 10:20 pm »

I just ordered a unit, I will report back here once I have given it a spin.

Thanks,
Ed

highfilter · « **Reply #74 on:** 14 Sep 2011, 06:11 pm »

Got the AQVOX USB Low-Noise Linear Power Supply last night. Popped it in and ran some tunes throw it for a few hours while I did some work around the house. Source was a Mac Mini and DAC used is the Tranquility SE. USB cable is from WyWires.

Sat down later and listened to a few tracks. I'll have to listen some more tonight and compare it in on/off, but first impressions were really good. Definitely either some more weight or defined mid-bass, because when I was playing some Electronica stuff like Autechre, I was really feeling it. Synth stuff sounds very very good, more defined and seems to have more clarity without sounding clinical or edgy.

Also tried some classic rock and female vocal stuff, and vocals definitely sound like they have a layer of harshness or grit removed. There was a certain energy that was different about the music than previously (will define and confirm when I swap the AQVOX on/off). Also felt like there was less congestion on complex or fast musical passages.

Overall a great late night listening session. Was really feeling the music and it seemed to grab me more than usual. I'll remove the AQVOX tonight to make sure I'm not just impressed with my current setup in general.

Everything fit snug and seems to be well made for the price. I also have the AQVOX power plugged into my UberBUSS.

Thanks for the heads up on this product, guys!

Dracule1 · « **Reply #75 on:** 14 Sep 2011, 07:13 pm »

You're welcome. I've experienced everything you've described.

gooberdude · « **Reply #76 on:** 14 Sep 2011, 07:49 pm »

That's what i experienced too.

You might wait a few days before A/B'ing it, to let it get broken in. For me it didn't require numerous days or any sort of effort, but seemed to get 'perfect' after 2 days & has stayed that way since.

Its a nice thing to get clarity & force injected at the same time, without negative side effects.

I'm tempted to buy a decent aftermarket schuko plug & diy a better power cord. In this application, should the power cable make a difference?

Dracule1 · « **Reply #77 on:** 15 Sep 2011, 05:38 pm »

Goober, do you mean a new power cord for the AQVOX?

gooberdude · « **Reply #78 on:** 15 Sep 2011, 10:57 pm »

Yup

The power cord on the aqvox which connects the 2 difft transformer boxes. It uses a schuko (european) 2 prong male connector & standard iec female plug. I would've already tried an aftermarket/diy power cord if I had one of the euro male plugs. Furutech makes them, just not sure its worth the $.

roscoeiii · « **Reply #79 on:** 15 Sep 2011, 11:03 pm »

And gooberdude, any chance to A/B with TRL?