Line only usb audio interface

Did you buy a new mixer? Do you need advice? Post here.
Forum rules
If you require help using Audacity, please post on the forum board relevant to your operating system:
Windows
Mac OS X
GNU/Linux and Unix-like
ingoogni
Posts: 26
Joined: Mon Dec 21, 2020 12:55 pm
Operating System: Windows 10

Line only usb audio interface

Post by ingoogni » Sun Dec 27, 2020 11:19 am

Do they exist? I'm looking for an USB audio interface with line inputs only. No microphone preamps. 4 channels would be fine.
All the search engines only seem to spit out lots of useless "Best 20 of 2020" lists nowadays.

Cheers.

steve
Site Admin
Posts: 81244
Joined: Sat Dec 01, 2007 11:43 am
Operating System: Linux *buntu

Re: Line only usb audio interface

Post by steve » Sun Dec 27, 2020 12:12 pm

ingoogni wrote:
Sun Dec 27, 2020 11:19 am
Do they exist? I'm looking for an USB audio interface with line inputs only. No microphone preamps.
Yes. Lots of them.
I use an earlier model similar to this: https://www.behringer.com/product.html?modelCode=P0484
The current version has a headphone socket, where as my ancient version has just analog stereo in / out + USB. There's no input level control, which is fine for me as I use it with a mixer and can control the input level from the mixer. It is now well over 10 years old, the label fell off a few years ago, but it still provides good service.
ingoogni wrote:
Sun Dec 27, 2020 11:19 am
4 channels would be fine.
They also exist, but they are less common, more expensive, and there's no guarantee they will work with Audacity. Many multi-channel devices have multiple stereo drivers rather than a single multi-channel driver (especially on Windows). Other software can get round this problem by using ASIO drivers, but Audacity is not able to ship with ASIO support due to licensing problems.
ingoogni wrote:
Sun Dec 27, 2020 11:19 am
All the search engines only seem to spit out lots of useless "Best 20 of 2020" lists nowadays.
Try searching specialist music retailers, such as Thomann.de, Gear4Music, dv247.com, bhphotovideo and similar.
9/10 questions are answered in the FREQUENTLY ASKED QUESTIONS (FAQ)

ingoogni
Posts: 26
Joined: Mon Dec 21, 2020 12:55 pm
Operating System: Windows 10

Re: Line only usb audio interface

Post by ingoogni » Sun Dec 27, 2020 12:35 pm

steve wrote:
Sun Dec 27, 2020 12:12 pm
Yes. Lots of them.
I use an earlier model similar to this: https://www.behringer.com/product.html?modelCode=P0484
I know that one. Had it but lost it somehow. Now I have a umc404hd.
Actually, I've just been looking at the signal path, could I use the return from the send/return as a line input, albeit unbalanced?
They also exist, but they are less common, more expensive, and there's no guarantee they will work with Audacity. Many multi-channel devices have multiple stereo drivers rather than a single multi-channel driver (especially on Windows). Other software can get round this problem by using ASIO drivers, but Audacity is not able to ship with ASIO support due to licensing problems.
I have / had my share of problems with that and the 404. Two thoughts on that,
Audacity is based on PortAudio (?) but I can't find a dll of it in the distribution. I assume it is compiled "inside" Audacity. Could it also be made with 'external' library? Then it would be a matter of switching the dll on Windows.

The other thing I noticed that the features of PortAudio seem to depend on how it is compiled. Using it in Python through the sounddevice package gives different options. The crosscompiled version gives me two channels on DirectSound and MME and problems simmilar to the ones people have with WASAPI. A compile on Windows gives me 4 channels on all hosts. (the Github issue on this matter)

Cheers.

steve
Site Admin
Posts: 81244
Joined: Sat Dec 01, 2007 11:43 am
Operating System: Linux *buntu

Re: Line only usb audio interface

Post by steve » Sun Dec 27, 2020 1:00 pm

ingoogni wrote:
Sun Dec 27, 2020 12:35 pm
could I use the return from the send/return as a line input, albeit unbalanced?
I don't see much benefit in doing that as it is just mixed in with the main input (but with no level control).

ingoogni wrote:
Sun Dec 27, 2020 12:35 pm
Audacity is based on PortAudio (?) but I can't find a dll of it in the distribution. I assume it is compiled "inside" Audacity.
Yes, PortAudio is compiled into Audacity. It allows Audacity to communicate with the computer sound system.
ingoogni wrote:
Sun Dec 27, 2020 12:35 pm
Could it also be made with 'external' library?
I think it would be "possible" to link dynamically to the PortAudio library, but I don't think there is any benefit in doing so. PortAudio isn't an "app", it's just a library. The main disadvantage of dynamic linking is that if you have the wrong version of PortAudio installed, Audacity won't run. Static linking ensures that Audacity can access the correct, compatible version of the library.
ingoogni wrote:
Sun Dec 27, 2020 12:35 pm
The crosscompiled version gives me two channels on DirectSound and MME and problems simmilar to the ones people have with WASAPI. A compile on Windows gives me 4 channels on all hosts.
The official release of Audacity for Windows is compiled on Windows 10 using MSVS.
9/10 questions are answered in the FREQUENTLY ASKED QUESTIONS (FAQ)

ingoogni
Posts: 26
Joined: Mon Dec 21, 2020 12:55 pm
Operating System: Windows 10

Re: Line only usb audio interface

Post by ingoogni » Sun Dec 27, 2020 5:53 pm

steve wrote:
Sun Dec 27, 2020 1:00 pm
ingoogni wrote:
Sun Dec 27, 2020 12:35 pm
could I use the return from the send/return as a line input, albeit unbalanced?
I don't see much benefit in doing that as it is just mixed in with the main input (but with no level control).
Tried it and it works. There's an old DIY mixer lying around here, it has outputs for all the inputs, so I just used it as a mic amp. There's nothing coming from the UMC404 input as the send signal is not patched through. Signal and clip lights work.

Cheers.

jademan
Forum Crew
Posts: 1279
Joined: Fri Jul 17, 2009 10:11 pm
Operating System: Please select

Re: Line only usb audio interface

Post by jademan » Tue Dec 29, 2020 3:15 pm

ingoogni wrote:
Sun Dec 27, 2020 5:53 pm
There's nothing coming from the UMC404 input as the send signal is not patched through. Signal and clip lights work.
I am not sure I follow what you are saying.. :?

ingoogni
Posts: 26
Joined: Mon Dec 21, 2020 12:55 pm
Operating System: Windows 10

Re: Line only usb audio interface

Post by ingoogni » Tue Dec 29, 2020 7:09 pm

jademan wrote:
Tue Dec 29, 2020 3:15 pm
ingoogni wrote:
Sun Dec 27, 2020 5:53 pm
There's nothing coming from the UMC404 input as the send signal is not patched through. Signal and clip lights work.
I am not sure I follow what you are saying.. :?
Have a look at the schema (PDF), I use insert 1-4.

There are no microphones or instruments plugged in to the front inputs. So there's no signal going through the preamps. Even if there was a signal from them, the send/return jacks break the signal flow as I didn't connect the send.
By using the returns as input you go from line level straight to the DAC.

jademan
Forum Crew
Posts: 1279
Joined: Fri Jul 17, 2009 10:11 pm
Operating System: Please select

Re: Line only usb audio interface

Post by jademan » Wed Dec 30, 2020 2:00 pm

ingoogni wrote:
Sun Dec 27, 2020 11:19 am
Do they exist? I'm looking for an USB audio interface with line inputs only. No microphone preamps. 4 channels would be fine.
All the search engines only seem to spit out lots of useless "Best 20 of 2020" lists nowadays.

Cheers.

So here is a 4-channel USB with RCA line inputs. And how could you go wrong with a brand like Mr. ? ;)
https://www.amazon.com/Mr-Dj-AD-IO-Chan ... B00BCA4D46

Here's another 4-channel USB box:
https://www.amazon.com/ESI-MAYA44-USB-A ... 002HLVQIA/

Use at your own risk. I hope this helps. :D

jademan
Forum Crew
Posts: 1279
Joined: Fri Jul 17, 2009 10:11 pm
Operating System: Please select

Re: Line only usb audio interface

Post by jademan » Wed Dec 30, 2020 2:10 pm

ingoogni wrote:
Sun Dec 27, 2020 12:35 pm
I have a umc404hd.
Actually, I've just been looking at the signal path, could I use the return from the send/return as a line input, albeit unbalanced?
I don't see why you couldn't do that if you wanted to do loopback recording. And I don't think being unbalanced is going to be a problem if you use a short 3 ft. cable.

jademan
Forum Crew
Posts: 1279
Joined: Fri Jul 17, 2009 10:11 pm
Operating System: Please select

Re: Line only usb audio interface

Post by jademan » Wed Dec 30, 2020 2:42 pm

ingoogni wrote:
Tue Dec 29, 2020 7:09 pm
Have a look at the schema (PDF), I use insert 1-4.

There are no microphones or instruments plugged in to the front inputs. So there's no signal going through the preamps. Even if there was a signal from them, the send/return jacks break the signal flow as I didn't connect the send.
By using the returns as input you go from line level straight to the DAC.
My bad. When I replied earlier I was looking at a picture of steve's UCA202. ;)

So is your 404 working properly now?

Post Reply