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REVIEW (more to come) - CEntrance DACport 24/96 USB DAC Amp - Page 19

post #271 of 479

I have the camera kit but seems a bit bulky to have to carry around an external power supply. Too bad. 

post #272 of 479

Momentary "glitches" when using the DACport LX

 

A friend of mine generously lends me his DACport LX whenever I feel like borrowing it.  He has had it for almost a year and really likes it except for a recurring problem of infrequent "dropouts," where the music is momentarily interrupted by a very brief crash of what sounds like white noise.  I think he would say it happens at least every three to five minutes of play, on average.

 

He has experienced the problem when using the LX on multiple Windows 7 PCs and laptops, and with an iMac, and has tried connecting it to multiple USB ports on each machine, with no improvement.

 

When I have borrowed his LX, I always connect it to a Windows 7 laptop at home, where I can go two or three hours without hearing the problem, but I get it too - just much less frequently.

 

I've told him that I believe the problem is related to insufficient amperage and/or voltage at the USB port.  Centrance literature documents that both the DACport and DACport LX invoke a USB 2.0 feature that allows a device to request up to 9 Volts from ports that normally provide only 5 Volts.  Given how hot the LX normally runs (as designed), it's obvious that it pulls a lot of volt-amps, compared to many other USB devices.  

 

So maybe these glitches / crashes are the result of insufficient power on the various machines that he has used, where my laptop is perhaps a little more capable of delivering what the LX needs.

 

Going on my theory, he has purchased an external USB hub that has an independent AC adapter, but that didn't make any improvement and, unfortunately, the various manufacturers of powered USB hubs don't seem to include the power specs of their AC adapters on their packaging nor in online documentation.  You have to buy the hub, open the packaging, and inspect the AC adapter's label to comparison shop the amp ratings.  Even then, you can't be sure that these hubs support the USB 2.0 convention that honors a device request for 9V instead of 5V.

 

Lastly, I want to add that he can exacerbate the frequency of occurrence by trying to use his machine for other purposes while music is playing - best results are had when he leaves the machine alone during playback.  And on my laptop, where I experience the problem very rarely, I've noticed a pattern of it happening when I move my USB-attached bluetooth mouse after it has sat motionless for quite some time, but it has also happened when I'm doing nothing at all, except listening - but again, with my machine, it only happens once every two three hours, and definitely not every time I move the mouse.

 

Has anyone else experienced this problem with either the DACport or DACport LX?  

 

Is this to be expected as a "normal" side effect of using using any USB-attached DAC that's powered by the port?

 

Solutions, comments?   Any ideas from non-users are welcome, too.  

 

Thanks!

 

Mike


Edited by zilch0md - 7/10/12 at 5:38am
post #273 of 479

Yes,  I have experienced this on my Dacport.  For me it happens when the power from my Macbook is insufficient.  I remember contacting Entrance about this long ago and they said the "noise" or "sound" is a result of the unit shutting down or powering up when the power source is insufficient or irregular. 

Quote:
Originally Posted by zilch0md View Post

Momentary "glitches" when using the DACport LX

 

A friend of mine generously lends me his DACport LX whenever I feel like borrowing it.  He has had it for almost a year and really likes it except for a recurring problem of infrequent "dropouts," where the music is momentarily interrupted by a very brief crash of what sounds like white noise.  I think he would say it happens at least every three to five minutes of play, on average.

 

He has experienced the problem when using the LX on multiple Windows 7 PCs and laptops, and with an iMac, and has tried connecting it to multiple USB ports on each machine, with no improvement.

 

When I have borrowed his LX, I always connect it to a Windows 7 laptop at home, where I can go two or three hours without hearing the problem, but I get it too - just much less frequently.

 

I've told him that I believe the problem is related to insufficient amperage and/or voltage at the USB port.  Centrance literature documents that both the DACport and DACport LX invoke a USB 2.0 feature that allows a device to request up to 9 Volts from ports that normally provide only 5 Volts.  Given how hot the LX normally runs (as designed), it's obvious that it pulls a lot of volt-amps, compared to many other USB devices.  

 

So maybe these glitches / crashes are the result of insufficient power on the various machines that he has used, where my laptop is perhaps a little more capable of delivering what the LX needs.

 

Going on my theory, he has purchased an external USB hub that has an independent AC adapter, but that didn't make any improvement and, unfortunately, the various manufacturers of powered USB hubs don't seem to include the power specs of their AC adapters on their packaging nor in online documentation.  You have to buy the hub, open the packaging, and inspect the AC adapter's label to comparison shop the amp ratings.  Even then, you can't be sure that these hubs support the USB 2.0 convention that honors a device request for 9V instead of 5V.

 

Lastly, I want to add that he can exacerbate the frequency of occurrence by trying to use his machine for other purposes while music is playing - best results are had when he leaves the machine alone during playback.  And on my laptop, where I experience the problem very rarely, I've noticed a pattern of it happening when I move my USB-attached bluetooth mouse after it has sat motionless for quite some time, but it has also happened when I'm doing nothing at all, except listening - but again, with my machine, it only happens once every two three hours, and definitely not every time I move the mouse.

 

Has anyone else experienced this problem with either the DACport or DACport LX?  

 

Is this to be expected as a "normal" side effect of using using any USB-attached DAC that's powered by the port?

 

Solutions, comments?   Any ideas from non-users are welcome, too.  

 

Thanks!

 

Mike

post #274 of 479
Quote:
Originally Posted by sling5s View Post

Yes,  I have experienced this on my Dacport.  For me it happens when the power from my Macbook is insufficient.  I remember contacting Entrance about this long ago and they said the "noise" or "sound" is a result of the unit shutting down or powering up when the power source is insufficient or irregular. 

 

Thanks sling5s!  

 

That reinforces my suspicions - which begs the question: 

 

Is anyone using an external USB hub with AC adapter that provides a stable power source for the DACport or DACport LX?

 

Thanks!

 

Mike

post #275 of 479
Thread Starter 

I've used the DACport with my Macbook Pro direct from USB and via powered HUB, and I DO NOT get any drop outs either way.  I'll try it with our regular white Macbook and see if that makes a difference, but it'll be a few days.

post #276 of 479

Thanks HeadphoneAddict!

 

Can you tell me the make and model of the USB hub?

 

Mike

post #277 of 479
Thread Starter 
Quote:
Originally Posted by zilch0md View Post

Thanks HeadphoneAddict!

 

Can you tell me the make and model of the USB hub?

 

Mike

 

It's a cheap 8-port USB 2 hub that I bought from 1saleaday.com and it's hiding under my listening chair, so I can't look right now.  I did have to upgrade the hub's PSU though, because the included wall wart would run quite hot.  Using a different 2A 5V wall wart runs nice and cool.  This same hub was noisy with the Audioengine D1 DAC, so go figure.

post #278 of 479

That's what I wanted to know, actually:  "2A 5V" - and that's a good idea for upgrading any USB hub to ensure that it can deliver plenty of current - just go to a higher amp rating but maintain the original voltage rating.   I'm pretty sure my friend's USB hub has a 5V adapter, but I don't recall what the amp rating was.

 

So, going back to your success using the DACport LX with a 5-volt 2-Amp USB hub, it begs the question:  How can the DACport LX request 9V from a hub that's attached to a 5V wall wart?   (I'm not asking you, so much as I'm just scratching my head.)

 

I would never try to replace a 5V wall wart with a 9V wall wart, but if I could find a USB hub that already comes equipped with a 9V wall wart at whatever amp rating, I'd be a lot more likely to assume that it's capable of honoring the USB 2.0 specification that allows a USB device to request 9 volts.  (I doubt that most of these inexpensive USB hubs equipped with a 5V wall wart contain a DC-to-DC converter that could take 5V to 9V.)

 

I think my friend feels ill-equipped to discuss all of this with Centrance, so I think it's time I give them a call and try to get their input on all of this.

 

More later...

 

Mike

post #279 of 479
Thread Starter 
Quote:
Originally Posted by zilch0md View Post

That's what I wanted to know, actually:  "2A 5V" - and that's a good idea for upgrading any USB hub to ensure that it can deliver plenty of current - just go to a higher amp rating but maintain the original voltage rating.   I'm pretty sure my friend's USB hub has a 5V adapter, but I don't recall what the amp rating was.

 

So, going back to your success using the DACport LX with a 5-volt 2-Amp USB hub, it begs the question:  How can the DACport LX request 9V from a hub that's attached to a 5V wall wart?   (I'm not asking you, so much as I'm just scratching my head.)

 

I would never try to replace a 5V wall wart with a 9V wall wart, but if I could find a USB hub that already comes equipped with a 9V wall wart at whatever amp rating, I'd be a lot more likely to assume that it's capable of honoring the USB 2.0 specification that allows a USB device to request 9 volts.  (I doubt that most of these inexpensive USB hubs equipped with a 5V wall wart contain a DC-to-DC converter that could take 5V to 9V.)

 

I think my friend feels ill-equipped to discuss all of this with Centrance, so I think it's time I give them a call and try to get their input on all of this.

 

More later...

 

Mike

 

My understanding is the DACport does a voltage conversion inside, it doesn't ask the USB for anything like 9v directly and only uses the 5v from USB to start with.  

post #280 of 479
Quote:
Originally Posted by HeadphoneAddict View Post

 

My understanding is the DACport does a voltage conversion inside, it doesn't ask the USB for anything like 9v directly and only uses the 5v from USB to start with.  

 

 

That would be great news if that's the case, as it would mean there's no reliance on a USB port providing more than 5V.  

 

I've not yet received a reply from Centrance to the e-mail I sent 22 hours ago.  I hope I didn't spook them, but I'll wait a couple of days before sending another email.

 

Mike

post #281 of 479

Centrance has responded to my email, asking me to have my friend contact them regarding the intermittent "noise crashes" heard with his DACport LX.

 

Not wanting to quote private correspondence directly, I do want to relay some information Centrance has provided regarding our earlier discussion, above:

 

The DACport and DACport LX actually do invoke a USB 2.0 feature that allows them to request 9 Volts from ports that normally provide only 5 Volts.

 

The Centrance representative says that any USB device can request 9 Volts from a USB port and said that pretty much all laptops and PCs do so, and thus, he does not believe my friend's DACport LX is suffering a lack of sufficient power, even intermittently.

 

UPDATE:  See the very next post in this thread.

 

More later, as this story unfolds...

 

Thanks!

 

Mike


Edited by zilch0md - 7/17/12 at 1:09pm
post #282 of 479

A different Centrance representative has sent an e-mail correcting the information I'd been given previously.  rolleyes.gif

 

Now, the word is that USB devices, including the Centrance DACport and DACport LX, can only request more current, not more voltage (from a USB port).

 

I have been assured that the DACport and DACport LX require no more than 5 Volts and that this is the maximum available to any USB-attached device via the USB port.

 

Meanwhile, I've passed the baton to my friend, to talk to them about returning his LX (to deal with the intermittent "noise crashes" he is experiencing.)

 

Mike

post #283 of 479

My guess is that he will be happy if he returns it for them to look at. I have had nothing but a positive experience each time I have dealt with them.  My DACPort has been used on a few laptops (and a desktop) without any glitch issue, both on battery and unplugged. 

 

As a side note from the posts a few weeks ago; I had the 1 ohm mod performed and it tightened up the bass considerably on low impedance IEMs.  Still zero hiss at full volume with the source paused.


Edited by deadkenny64 - 7/18/12 at 9:55am
post #284 of 479

Thanks for the encouragement!

post #285 of 479
Quote:
Originally Posted by zilch0md View Post

[snip]

 

Meanwhile, I've passed the baton to my friend, to talk to them about returning his LX (to deal with the intermittent "noise crashes" he is experiencing.)

 

Mike

 

Good news:  

 

My friend with the DACport LX that was suffering intermittent "noise crashes" has been working with a fellow at Centrance who solved his problem with this suggestion:

 

> If you have our Universal Driver installed, I recommend uninstalling it
> unless you are exclusively using DACport LX with ASIO-compatible
> playback software.

 

That was it!   Early on, he had installed the Universal Driver unnecessarily.  Now, with the Universal Driver removed, his DACport LX is playing flawlessly!

 

Well done Centrance!  biggrin.gif

 

Mike

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