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

Dracule1 · « **on:** 30 Jul 2011, 10:12 am »

I have not written any reviews in a long time because nothing really has excited me to this extent in awhile. This device improves the sound as much as any source component change I have made in recent memory. Hence, my review under source component category. I have spent the last several years building dedicated audio room with all new components and room treatments at significant financial cost. When something so affordable comes along that can make this kind of improvement, I feel obligated to pass my experience to you.

AQVOX power supply hooks into the USB port on your DAC. You can go to their website and see the details:

http://www.aqvox.de/usb-power_en.html

How does it sound? I hooked it up to my dB Audio Labs Tranquility SE DAC, and the improvement was immediate. No guessing involved here. It actually took me by surprise because I was expecting incremental improvement at most. This thing just opened up the sound. Vocals and instruments gained more body and weight with increased midrange detail and cleaner highs. The background became eerie black. The small amount of upper midrange/lower treble grunge that was in my system was banished. Micro- and macro-dynamics slightly improved. However, the bass impact and extension did not improve significantly in my rig. What it did to sound stage and imaging was remarkable. The sound stage moved up closer to the listener. The sonic images became more full or larger, but somewhat paradoxically the air around the instruments and vocals was increased resulting in better separation. The overall effect was music became more intimate. The most notable and most important improvement for me was the naturalness of vocals and instruments when this device was in play. Everything sounded less electronic, and I was able to relax and enjoy the music more. Considering its price, it qualifies as one of the most, if not the most, significant upgrade I have made.

I'm not sure if AQVOX will make a significant improvement in your system. It may depend on the resolution of your system and the pollution in your digital rig. Given most audiophiles spend more on cables and tweaks that result in dubious improvement, you owe it to yourself to try this. It comes with a 30 day money back guarantee. The only draw back is it ships from Germany, and shipping can take several weeks as it did in my case.

I have no financial interest or other conflicting affiliation with this company. I'm just a very satisfied customer.

gooberdude · « **Reply #1 on:** 30 Jul 2011, 02:23 pm »

An interesting product.

Does it take the place of the ac cord, or is it used in conjunction with it?

I have the std Tranquility dac.

Paul B · « **Reply #2 on:** 30 Jul 2011, 02:45 pm »

I also have the std tranquility and have a power supply on order.

My understanding is that it supplies power to the USB receiver chip (replacing the supply from the computer) so works together with the ac supply.

gooberdude · « **Reply #3 on:** 30 Jul 2011, 02:50 pm »

thx!

i'll definitely try this too.

my mini+Tranquility set up is nice, but it would be great if the musicians were more spread out.

Dracule1 · « **Reply #4 on:** 30 Jul 2011, 06:27 pm »

It does not take place of the AC cord of your DAC. When AQVOX is in line, the musicians will be more "spread out" in a sense there will be more air around them...more holographic. You can hear the boundries of the soundstage better, so the soundstage seems to grow in all directions. I was having trouble with singers' voices imaging just above the top of the speaker in some recordings (speakers are about 44 inches in height). Now the voices are consistently realistic in height, about 5 to 6 feet above the floor. I have a very high resolution system, but have been dissatisfied of what my system was able to achieve sonically. The AQVOX was the final touch that got my system to a level that I knew it was capable of.

highfilter · « **Reply #5 on:** 30 Jul 2011, 07:02 pm »

Looks like a great product. Thanks for the heads up!

Also have a Tranquility SE DAC and will probably try this out.

roscoeiii · « **Reply #6 on:** 30 Jul 2011, 07:08 pm »

Mighty interesting. Always like a 30 day trial. What do the shipping costs look like to the US?

Dracule1 · « **Reply #7 on:** 30 Jul 2011, 10:01 pm »

It was 118 Euro total (power supply, AC converter, paypal fee, and shipping to US). At current exchange rate, it is ~$170.

gooberdude · « **Reply #8 on:** 3 Aug 2011, 12:32 am »

I just placed an order. $119 euro

ted_b · « **Reply #9 on:** 3 Aug 2011, 12:57 am »

It looks quite interesting. I'm going to try another route to the same place, but will report back if I am gonna try this too.

I have Revelation Audio sending me one of their DualConduit USB cables, which separates the power cabling from the signal cabling at the source end (i.e 2 connectors at one end, one at DAC end) This allows a couple things: better isolation of power from signal than most cabling (which uses internal shielding), and the option to use non-computer power sources at the source end (USB wallwart? USB powered hub?, dunno what is best).

My main question to both of these approaches (AQVOX and dualconduit cabling) is this: what do most AC-powered USB DACs use the bus power for anyway?? Is the Tranquility DAC somehow bus powered for some of its capabilities? I have the same question in to Antelope about my Antelope Gold USB DAC. I understand self-powered DACs like HRT streamers, etc would use USB bus power exclusively, but assumed most AC-powered DACs , like my former DAC, the AC-powered firewire Weiss DAC2, don't need bus power at all. (I.e would Dracule1's same effect be observed if the power lines were cut and/or removed on a standard USB cable of choice? ) Anybody?

Dracule1 · « **Reply #10 on:** 9 Aug 2011, 03:55 am »

Teb_b, my USB cable is a dual cable also (cable for vbus and cable for data connect together at the DAC end), Ridge Street Audio Enopias. It is a definite improvement over the Tranquility USD cable. However, the AQVOX provided a more significant improvement in sound in my system.

ted_b · « **Reply #11 on:** 9 Aug 2011, 04:41 am »

Draggle, where then do you connect the AQVOX if using the RSA dual conduit USB cable? At the source end, in the power "A" connector, or at the DAC end? If at the DAC end isn't the dual conduit design somewhat wasted (ie u don't even have anything transmitted through the power half of the dual cabling)? Thx
Ted

Dracule1 · « **Reply #12 on:** 11 Aug 2011, 10:23 pm »

The usb connector from the AQVOX goes into the DAC and the single end of the RSA usb cable connects on top of that. The other two ends of the RSA cable connects to two USB ports on the Mac Mini.

ted_b · « **Reply #13 on:** 11 Aug 2011, 11:03 pm »

Quote from: Dracule1 on 11 Aug 2011, 10:23 pm

The usb connector from the AQVOX goes into the DAC and the single end of the RSA usb cable connects on top of that. The other two ends of the RSA cable connects to two USB ports on the Mac Mini.

My question is why? If you are delivering power to the DAC via the AQVOX why are you even bothering to connect/add power at the source/computer end (being that you have that luxury with dual connections)?

gooberdude · « **Reply #14 on:** 11 Aug 2011, 11:20 pm »

Would it be correct to think that a usb cable, custom made so it had no ac current running through it - just the signal wires, would be best when using the aqvx psu?

(pretty sure that is what the question is about)

RAL makes the best interconnects & power cords i've ever owned, no doubt their usb cable is excellent though i haven't tried it. My Tranquility dac likes the db audio Essential Signature cable.

the aqvx psu s/b here in a week or so.

ted_b · « **Reply #15 on:** 11 Aug 2011, 11:25 pm »

Quote from: gooberdude on 11 Aug 2011, 11:20 pm

Would it be correct to think that a usb cable, custom made so it had no ac current running through it - just the signal wires, would be best when using the aqvx psu?

(pretty sure that is what the question is about)

RAL makes the best interconnects & power cords i've ever owned, no doubt their usb cable is excellent though i haven't tried it. My Tranquility dac likes the db audio Essential Signature cable.

the aqvx psu s/b here in a week or so.

Problem is that the AQVOX (or any other 3rd party power source) would need the wires/connectors to attach to, so the USB cable would need to NOT have the power wires stripped out, but instead "simply" missing at the source end.

gooberdude · « **Reply #16 on:** 12 Aug 2011, 01:11 am »

I've read posts where guys clipped the power wires on the source end & left everything in place.

i'm not about to clip my usb good cable, but have a few freebie cables lying around to play with.

Dracule1 · « **Reply #17 on:** 12 Aug 2011, 03:09 am »

Ah I see what you're getting at. The RSA usb cable was not designed with AQVOX in mind. It was designed to separate the data and vbus. I suppose I can just connect the data wire and not connect the vbus wire to the Mac mini. I'll ask RSA if this would be ok. Don't want to damage anything. A little knowledge can be dangerous.

Dracule1 · « **Reply #18 on:** 23 Aug 2011, 03:09 am »

Any one of you who ordered the AQVOX receive the unit yet? How does it sound in your system?

gooberdude · « **Reply #19 on:** 23 Aug 2011, 03:13 pm »

Still waiting, patiently

As of today i'm 21 days into the order.

Funny thing is I haven't listened to the Tranquility much the last few weeks. On a whim I bought a TRL modd'd sacd changer & have been enthralled with its performace, especially in comparison to the stock Tranquility.

I do hope the AQVOX psu will improve the Tranquility. If it allows the Tranquility to throw as wide & deep a stage as this TRL changer, i'll owe Dracule1 big time.

matt