USB Sound Card/Device comparisons

[clemfm]

As per my post here http://forums.radioreference.com/li.../235253-scanner-feed-using-rasberry-pi-8.html I compared a Griffin iMic to an Edirol UA-5 and was not so surprised to find that the Edirol's ADC produced a much quieter signal when I captured 20 seconds of lull between transmissions on the same frequency and only a few minutes apart. Both periods sounded the same, except for the background noise.

I would love to know how this compares to what other 'streamers' are achieving:

I may share my stream at some point, however here are my actual tests using:
- Optoelectronics Xplorer scanner (near field receiver actually)
- Radio Shack 21-543 Digital Signal Processor inline and set to 'Narrow Bandwidth'
- A Mac running OSX 10.8.5
- iTunes receiving the m3u stream
- Soundflower/Flowerbed redirecting the Mac's audio so that
- Audacity captured the stream.

iMic first and then Edirol:

 

[Bellingham_Scanner]

I know it's not USB cards, but in my mini-ITX system I use a Sounblaster Live! for my police feed and the on board Realtech chip for my fire feed.

The Soundblaster Live! is dead silent between calls while the Realtech is full of background noise.

Could be proximity to other motherboard components or the fact that Realtech sound chips just suck.

EDIT: More comments...

I really do not see the point in spending a ton of money on a sound card considering the limited bandwidth of scanner audio. On my feed's facebook page I recommend listeners to use the EQ on their player in a bandpass peaking the sliders in approximately 500hz-2.5Khz range and set all sliders above and below as low as they will go. That cleans up the slightly mechanical overtones the low sampling rate causes, kills a lot of the background noise, and makes speech sound clearer.

 

[flythunderbird]

I know it's not USB cards, but in my mini-ITX system I use a Sounblaster Live! for my police feed and the on board Realtech chip for my fire feed.

The Soundblaster Live! is dead silent between calls while the Realtech is full of background noise.

Could be proximity to other motherboard components or the fact that Realtech sound chips just suck.

I would tend to echo your thought that Realtek chips suck, at least in certain applications.

I just brought my feed up. I use a BC860XLT, which sends audio to an HP T5730 thin client via a Behringer U-CONTROL UCA202 USB audio interface. Like your Soundblaster Live!, the Behringer is dead silent between calls. I tried the microphone-in jack on the thin client, and I wasn't very happy with it ... it was VERY finicky. The thin client has a Realtek sound chip, but it doesn't have a line-in jack. The USB interface is much better to work with IMO.

 

[clemfm]

I just bought a Xitel Hotwire from Amazon on sale for$5.99

http://www.amazon.com/Xitel-Inport-Hotwire-Recording-Headphone/dp/B003EXUA4G

Opening it up, I found a UAC3556B UAC (universal audio controller I.e. Combined DAC/ADC), the same UAC in my iMic and so I won't bother testing it.

Datasheet is here http://www.kako.com/neta/2005-009/uac3556b.pdf

$5.99 is very cheap though if you need an iMic replacement,