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

highfilter · « **Reply #40 on:** 30 Aug 2011, 03:21 am »

I believe the idea is of noisy power transferring from the computer into the DAC via the power line in the USB cable. The AQVOX is supposed to fix that and use it's own linear power. I believe that's the idea. Could also be a power issue for the receiver in the DAC.

Maybe even if the DAC doesn't power itself through the USB, the noisy power line could still be passed through into the receiver in the DAC and cause some issues there.

Not too sure of all the technical stuff myself, just is how I interpreted it.

I have ordered one and will hear what it has to offer.

ted_b · « **Reply #41 on:** 30 Aug 2011, 03:30 am »

Quote from: highfilter on 30 Aug 2011, 03:21 am

Maybe even if the DAC doesn't power itself through the USB, the noisy power line could still be passed through into the receiver in the DAC and cause some issues there.

And my point is: if the DAC is powered elsewhere and doesn't need USB bus power, then wouldn't NO power be the best option, not just cleaner power. I have determined, at least for DACs like my Antelope Gold, that the 5V is used to sense a connection, then not used (i.e I have a dual conduit cable that allows me to unplug the power after handshake...silence is golden). So......I'm wondering why cleaner power from the AQVOX is making things so much better...if no power is needed in the first place. Why not just cut or cover the power connections.

For USB-bus powered DACs (HRT streamer, etc) this does not apply. The AQVOX is clearly an upgrade to computer power in that instance.

I think I will ping Eric and find out what the Tranquility does with the 5V.

highfilter · « **Reply #42 on:** 30 Aug 2011, 04:16 am »

Ah yes. I see your point.

Cleaner power could be an improvement, but no power would be ideal (if possible).

I sent Eric a message and I'll see what he says about how the DAC handles the USB power.

I am also interested to see the results on external hard drives etc.

Dracule1 · « **Reply #43 on:** 30 Aug 2011, 01:33 pm »

Gooberdude, you're welcome

. You've corroborating my findings. I'm glad I wasn't just hallucinating.

Dracule1 · « **Reply #44 on:** 30 Aug 2011, 01:36 pm »

I asked Eric about whether AQVOX would improve the Tranquility before I ordered it. He said that although Tranquility is not USB powered, it still has to "see" the 5 volts from the USB. He said it couldn't hurt to try it out. So I did and was surprised at the result. I think what Highfilter said makes sense in this case.

Audioclyde · « **Reply #45 on:** 30 Aug 2011, 01:44 pm »

I have the dual conduit Audio Revelation USB cord on the way (hope it arrives today) to try with my Tranquility SE. I will try the hook-up as Ted has with his Zodiac Gold (i.e., try unplugging the pwr leg after the computer handshake with the DAC) and see what happens.

I am really interested in the AQVOX, but got a chance to grab the used AR dual conduit cable and decided to try that first.

Randy

gooberdude · « **Reply #46 on:** 30 Aug 2011, 01:54 pm »

I'm considering buying a new usb cable to work in conjunction with the aqvox psu, makes perfect sense to me now.

A/B'ing my Tranquility with or without the psu makes a huge audible difference.

Audioclyde · « **Reply #47 on:** 30 Aug 2011, 02:02 pm »

I have the Locus Axis and the Wywires USB cables in house, so comparing the new Audio Revelation dual conduit will hopefully be fun.

If the dual conduit cable doesn't make a difference (or won't work with the pwr leg detached), I will be seriously considering the AQVOX!

ted_b · « **Reply #48 on:** 30 Aug 2011, 02:30 pm »

Not to hijack (again) but give the dual conduit a few days to settle in. Big diff.

Socrates7 · « **Reply #49 on:** 30 Aug 2011, 03:14 pm »

Ted_B -- I'm sure you said this elsewhere, so at the risk of redundancy and in total service to my laziness, what dual-leg cable are you using?

ted_b · « **Reply #50 on:** 30 Aug 2011, 03:23 pm »

Quote from: ted_b on 23 Aug 2011, 03:47 pm

I've been enthralled with the dual conduit Revelation Audio Labs USB cable. The power leg only needs to be connected to my Mac Mini during handshake, then once the Antelope Gold driver is seen the power leg can be pulled (for listening). It has been in that state (no power, just signal leg connected) for about a week now. The noise floor is soooo low that microdetails, ambient cues, harmonics, etc are fabulous. I'm very exceited by this potential. Net/net, no need to worry about USB power quality when you don't need USB power.

here ya go Scot

Socrates7 · « **Reply #51 on:** 30 Aug 2011, 03:30 pm »

Revelation?

Did you get a chance to try/compare with the Acoustic Revive USB-SP? Or did someone do that?

Thanks (and sorry for the diversion).

ted_b · « **Reply #52 on:** 30 Aug 2011, 03:39 pm »

Quote from: Socrates7 on 30 Aug 2011, 03:30 pm

Revelation?

Did you get a chance to try/compare with the Acoustic Revive USB-SP? Or did someone do that?

Thanks (and sorry for the diversion).

No, I haven't found the USB-1.0SP (AR lost their US distrib for awhile) and it's 3x more $$ too. Same idea, though...that's what intrigued me by Brad's design. I know his cables from Modwright (Dan uses his power umbilicals from mod/line stage to power supply) days.

highfilter · « **Reply #53 on:** 30 Aug 2011, 04:13 pm »

Just got this response from Eric via the USB power on the Tranquility:

Quote

HI Clayton,

The Tranquility and the Tranquility SE are designed for USB connectivity with the computer where the power in the USB cable is needed. That said, we have been working on an innovative method to address this "need for voltage" in a positive way sonically that has a different connection scheme. That's about all I can say for the next month (when we are closer to the RMAF show) where we will have new products available of many types (hint, hint

Sorry I can't give you exact details at this time. The good news is that we've found quite a few significant sonic improvements and those will be brought to market for all Tranquility owners.

Cheers,

Eric Hider
dB Audio Labs

jrebman · « **Reply #54 on:** 30 Aug 2011, 11:21 pm »

Ted,

I believe the answer to your question about why the aqvox works so well is that the power line from he computer is properly terminated so as to reduce power linenoise from contaminating the signal lines., and my guess is that thee termination is close to the computer side of the cable, so only the clean DC fromthe AQ Vox supply is in proximiity to the signal lines. Otherwis, you're completely correct, just removing the 5v supply once the receiver chip has been "booted", then the Tranquility doesn't need it anymore than the Zodiac.

-- Jim

Dracule1 · « **Reply #55 on:** 31 Aug 2011, 04:03 pm »

After my positive experience, I told Eric Hider and he has ordered the AQVOX as well. We'll see how he likes it.

ted_b · « **Reply #56 on:** 31 Aug 2011, 04:54 pm »

Quote from: Audioclyde on 30 Aug 2011, 02:02 pm

I have the Locus Axis and the Wywires USB cables in house, so comparing the new Audio Revelation dual conduit will hopefully be fun.

If the dual conduit cable doesn't make a difference (or won't work with the pwr leg detached), I will be seriously considering the AQVOX!

Audioclyde,
Make sure you check with Eric before pulling the power leg. I'm not sure how the Tranquility uses the USB receiver, and we don't want the receiver ground altered if it is looking for ground, etc.

Audioclyde · « **Reply #57 on:** 31 Aug 2011, 04:56 pm »

Thanks Ted; will do so. The cable hasn't arrived yet (after 1 week), and I purchased from someone in Florida--I've now seen some of the 'old' threads on the web re delivery times, so I'm wondering.....

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

ted_b · « **Reply #58 on:** 31 Aug 2011, 05:01 pm »

My U3 should arrive Fri or so...I'll let u know...I'm hoping too!

TomS · « **Reply #59 on:** 31 Aug 2011, 06:10 pm »

Quote from: ted_b on 31 Aug 2011, 04:54 pm

Audioclyde,
Make sure you check with Eric before pulling the power leg. I'm not sure how the Tranquility uses the USB receiver, and we don't want the receiver ground altered if it is looking for ground, etc.

Yes, I would be VERY careful doing this sort of thing with just any USB device. I made a little USB junction box with switches and such for routing power sources and grounds to the device in a controlled way. Even then, proceed with caution based on what the device supplier says.

The AQVox looks like a very nice solution if your device needs the +5v full time (i.e. fully bus powered) and you don't already have a good clean +5v external power supply available. The USB/power adapter looks to be a little bit fragile where the power cord attaches, but it's hard to tell from the small pictures. Is it just the 3 connectors heat shrinked together or is there some sort of cover or shell on it?

From reading their site I couldn't find if they offer just the adapter itself so you could try a Paul Hynes supply or something similar. That would be a nice option for some folks.