# USB interface questions?



## eyesandears (Apr 25, 2012)

Hello,

Newbie to this forum and my first post. Been lurking for a while and learning lots!

I am looking for a good quality USB/mic audio interface to use with my laptop for room acoustic and audio analysis and have two questions.

1. USB 1.1 vs 2.0? Is there a noticeble delay or data speed diff. between these two. Many interfaces don't specify USB 2.0. Are they?

2. I would prefer an interface with balanced outputs for my home system with all balanced inputs but would like unbalanced outputs available for other systems I may use it on. Only a few units have both. If I buy one with only balanced outputs is there any simple way to feed unbalance inputs (without adverse effects)or will that absolutely require a outboard bal/unbalanced converter box (transformer) as well? (For example, a possiblity I reviewed is the M-Audio Fast TrackPro which appears to have both type outputs but using USB v?? not specified)

Thanks in advance for any assistance.

Mark


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## Gregr (Nov 2, 2010)

Hi, Welcome! There is/are many people here who know this stuff top to bottom, front to back, etc, etc I am not one of them but I can shed some light on your question. Hold onto your hat....,

I don't know of a motherboard made in several years using a USB 1.1 spec. I am not sure that any of the hardware made for 1.1 USB will have the Audio quality you are asking about anyway. In the year 2000 the USB Hi-Speed 2.0 spec came along with higher bandwidth and a low voltage for peripherals. 2.0 spec uses Mini-A and Mini-B plugs. I believe the 1.1 spec used the same size plugs as the 2.0 spec but the 2.0 spec added a few pins. Now, since 2008, we are using the USB Superspeed 3.0 spec with the same Mini-A and B plugs with more added pins and allowing for added speed and increased bandwidth again. The 3.0 spec was required and is reverse compatible with 2.0 spec using the same size plugs again but with added pins. I should add that the 3.0 spec increases voltage but adds power conservation protocols.

USB 2.0 and 3.0 I believe is where you will find the better digital audio technology. If you haven't looked at Cambridge Audio's DACMagic I suggest you start there 

Audio Advisor dot com has DACMagic in two iterations. Each have balanced or unbalanced outs and several types of inputs Including USB 2.0.

I hope this helps...,Keep us informed, please? :wave:


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## Wayne A. Pflughaupt (Apr 13, 2006)

eyesandears said:


> 2. I would prefer an interface with balanced outputs for my home system with all balanced inputs but would like unbalanced outputs available for other systems I may use it on. *Only a few units have both.*


Are you sure? From what I’ve seen, units with both balance and unbalanced ins and outs are common. For instance, it’s even included in the feature list of the M-Audio Fast Track Pro you’re interested in.

If you’re only looking at the on-line pictures of various interfaces to see what connectors they have, perhaps it would be beneficial to know a bit more about them. Most have “combi-jack” inputs that will accept both XLR and 1/4” (note the hole in the center of the connector for the 1/4" plug). The rear panels often have TRS outputs that will accept both  balanced (TRS) 
and  unbalanced (TS) 1/4" plugs.

Regards, 
Wayne


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## eyesandears (Apr 25, 2012)

Thanks for the quick responses. 

I think I was seeing that only a few units still have unbalanced RCA connector outputs. But all now have the TRS outputs

I have been doing more research and now it makes some more sense after reading a few of the USB interface manuals I have downloaded. I was concerned about the usual higher balanced output voltages but that probably won't be an issue with the recommended connections.

Cheers!


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## Gregr (Nov 2, 2010)

You know I am probably going to open dialog insert keyboard (ouch) but I remember the old and still used speak-on's, however, with an XLR on one end and TRS on the other. In the back of my mind that was just our making due with what we had for cheap connectors. XLR's are pricey even for a cheap XLR. 

But they work. Why not.

One day I will own Krell Pre/Pro and Amps and balanced connectors will matter again.

I love the DACMagic, I've been thinking this could be an improvement over my sound card. However, With a seperate power supply and digital clock. Several companies have designed exactly that for the DACMagic.


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## MysticDan (Nov 13, 2011)

Its all how much you want to spend. Tell us.


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## Gregr (Nov 2, 2010)

Dan, who are you writing to? What are you writing about? 

If its about seperates for the DACMagic..., Pangea for $99 sold by Audio Advisor makes a seperate PS. AA came out with this after MapleShade.com marketed their upgrade for the DACMagic specifically. MapleShade is a company I am very interested in many of their ideas and products. Take a look.

Is this what you are looking for?


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