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Windows 7 USB audio line in... Where is it?

post #1 of 10
Thread Starter 

I recently bought an analog-to-digital converter to simplify the process of adding LPs to my computer-based music system. The music library is kept on an offboard hard disk system connected to a Mac Mini, but I wanted to use my Windows 7 PC for the LP transfers because of its greater memory and hard-disk space.

 

I connected the ADC to the PC, and set its inputs so it could receive the digital stream. That part works. The problem is that in the Windows 7 audio control panel I have no indication of a line input. The signal from the ADC is being treated as a mic-level input, with the microphone icon, and of course the input is overloaded by the ADC's line out put.

 

I've looked everywhere I can think of to find some way to change that USB audio input from mic-level to line-level, without success. Even the driver that came with the sound card (Creative Recon 3D) offers no help. A search on the Web showed some other folks asking the same question, but no working answers. Does anyone here have a suggestion?

 

In the meantime, I simply switched to using the SP/DiF optical connection, and that works well. The USB question is more curiosity than anything else. I'm wondering what I've missed.

post #2 of 10

Which ADC do you have there?

 

Does the ADC need a driver been installed?

post #3 of 10
Thread Starter 

It's a Benchmark ADC1 USB. According to Benchmark, no drivers are required.

 

I talked with Rory Rall at Benchmark today, and his original recommendation was to go ahead and turn down the volume on the mic input so that it wouldn't be overloaded. In analog terms this would be a bad idea, but I suddenly realized that on a digital signal it might not matter. Then Rory went off to talk with someone else, and came back to say that, while in the past they've preferred using USB over using a sound card input, they now say that the SP/DIF connection on optical is fine.

 

I've used this to copy two more LPs to 24/96 files, and I've compared them to the 16/44.1 files made using an Alesis Masterlink recorder. Whatever goodness there is in the CD quality, I think I hear more of it in the 24/96 files.

post #4 of 10

Through S/PDIF the signal is 1:1 original so to avoid additional noise, just keep the other inputs of Recon closed.

 

Maybe Alesis recorder is not as good in quality (not flat frequency response, weak dynamic range or high noise level and maybe there are some filters (subsonic/antialiasing) added as well) as the ADC1 is so maybe that explains most of the difference between 16/44.1 and 24/96 recordings.

 

What recording software are you using (remember that std Audacity does not support 24-bit recordings).

post #5 of 10
Thread Starter 

When I listened to 24/96 recordings directly from the Masterlink, they sounded very good. At the time I was recording only spoken word from a house mixer, and even with that I thought the recordings sounded better than anything else I'd done. Some years later, when I started copying LPs, I'd forgotten about that and simply let the Masterlink make a CD; I've never listened to its music output on anything other than monitoring headphones.

 

I'm using Audacity to make my current LP recordings. I've checked every step of the process and the files always show as 24/96. Audacity records at 32-bit float, by default, and I set the sample rate to 96k. When I export the final tracks, I do so as AIFF 24-bit. Audacity can't save at ALAC, which would be my preference, as one LP is a gigabyte. Data rate in Itunes when I play it back is a little over 4Mb per second, which works out mathematically. So, unless something is hidden from me and being masked by inaccurate numbers, I'm getting 24/96 files out of the process. If so, the difference I hear is all in my head...

 

I'm trying an experiment now. Years ago I bought an LP of Charlie Dore's "Pilot of the Airwaves" and made a CD using a friend's CD recorder. Later on I re-did it with the Masterlink. Later still, a commercial CD came out, so I bought that. Now I've dusted off the LP and have recorded it with the new system, and will make an informal comparison. The comparison will be complicated by the fact that the CD is relatively low in volume, which is part of the reason I'm making my own, and we all know how loudness affects perception of sound quality. Still, it's a useful exercise, as I'm learning more about how to make a good recording of these old LPs, some of which (like Dave Brubeck and Gerry Mulligan's "Compadres" live album) aren't on CD at all.

post #6 of 10
Quote:
Originally Posted by Lord Chaos View Post
 

I'm using Audacity to make my current LP recordings. I've checked every step of the process and the files always show as 24/96. Audacity records at 32-bit float, by default, and I set the sample rate to 96k. When I export the final tracks, I do so as AIFF 24-bit. Audacity can't save at ALAC, which would be my preference, as one LP is a gigabyte. Data rate in Itunes when I play it back is a little over 4Mb per second, which works out mathematically. So, unless something is hidden from me and being masked by inaccurate numbers, I'm getting 24/96 files out of the process. If so, the difference I hear is all in my head...

There should be no reason you're not getting 24/96. If you want to save on HDD space, why don't you just save out to FLAC and convert to ALAC after the fact? 

 

Edit: I was wrong, don't want to spread misinformation, read below. Question still stands though!


Edited by brhfl - 2/21/14 at 9:26am
post #7 of 10
Quote:
Originally Posted by Lord Chaos View Post
 

When I listened to 24/96 recordings directly from the Masterlink, they sounded very good. At the time I was recording only spoken word from a house mixer, and even with that I thought the recordings sounded better than anything else I'd done. Some years later, when I started copying LPs, I'd forgotten about that and simply let the Masterlink make a CD; I've never listened to its music output on anything other than monitoring headphones.

 

I'm using Audacity to make my current LP recordings. I've checked every step of the process and the files always show as 24/96. Audacity records at 32-bit float, by default, and I set the sample rate to 96k. When I export the final tracks, I do so as AIFF 24-bit. Audacity can't save at ALAC, which would be my preference, as one LP is a gigabyte. Data rate in Itunes when I play it back is a little over 4Mb per second, which works out mathematically. So, unless something is hidden from me and being masked by inaccurate numbers, I'm getting 24/96 files out of the process. If so, the difference I hear is all in my head...

 

I'm trying an experiment now. Years ago I bought an LP of Charlie Dore's "Pilot of the Airwaves" and made a CD using a friend's CD recorder. Later on I re-did it with the Masterlink. Later still, a commercial CD came out, so I bought that. Now I've dusted off the LP and have recorded it with the new system, and will make an informal comparison. The comparison will be complicated by the fact that the CD is relatively low in volume, which is part of the reason I'm making my own, and we all know how loudness affects perception of sound quality. Still, it's a useful exercise, as I'm learning more about how to make a good recording of these old LPs, some of which (like Dave Brubeck and Gerry Mulligan's "Compadres" live album) aren't on CD at all.

 

When you record using more than 16-bit resolution in Audacity (Windows version), the recorded data is represented with 16-bits and the rest 8-16 bits- becomes filled with zeroes:

 

16-bit - 1010110010110111

24-bit - 101011001011011100000000

32-bit - 10101100101101110000000000000000

 

Audacity team has informed this many years ago and can't fix the issue other but by offering the ASIO support so, if you really want to record 24-bit resolution then you need either compile the Audacity project with ASIO support libraries or use other software which is capable for 24/96 recording (there are these available even as freeware).


Edited by jiiteepee - 2/21/14 at 9:20am
post #8 of 10
Quote:
Originally Posted by brhfl View Post
 

There should be no reason you're not getting 24/96. If you want to save on HDD space, why don't you just save out to FLAC and convert to ALAC after the fact? 

 

Believe or not but with std Audacity (for Windows) it's not possible to record 24/96 audio just because of 24-bit recording is not supported w/o ASIO support libraries (you have to compile the project by yourself to get this working).


Edited by jiiteepee - 2/21/14 at 9:20am
post #9 of 10

Gotcha! I do vaguely remember having to go through some hoops when recording back in my PC days, though I was using Saffires and other multitrack inputs... hoops were a given... ;)

post #10 of 10
Thread Starter 

Thank you for the information. I wish there'd been something in the Audacity documentation that mentions this; everything I read in the manual touts the 32-bit recording, with no hint that I needed to get other drivers.

 

This brings up the question: What does Audacity do with the 24 bits the ADC1 is sending? I'm using Audacity only to receive the digital stream and write it to the hard disk, and then edit into tracks.

 

Edit: I checked the Audacity forum, and a post there indicates that 24-bit input is truncated to 16 bits, and then, when saved as a project, is converted to 32-bit float.

 

Edit 2: In doing some more research, I've discovered that Windows 7 has multiple audio "hosts," one of which is WASAPI. This seems to be a direct connection to the sound card, and, according to the Audacity info, allows 24-bit recording. My confidence is a tad shaken, however, so I'm wondering if it's really that simple. Just set Audacity to use WASAPI? Testing, testing, 1... 2... 5...

 

Edit 3: WASAPI doesn't work. Apparently it's a copyright issue. Audacity can't be distributed with that kind of ASIO support integrated, so it's roll your own.


Edited by Lord Chaos - 2/21/14 at 11:01am
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