Maker Pro
Maker Pro

Is it safe to connect line level to lo Z mic jack on audio interface?

dietermoreno

Dec 30, 2012
238
Joined
Dec 30, 2012
Messages
238
Is it safe to connect line level to lo Z mic jack of audio interface?

I was attempting to record a guitar cover with an M-Audio interface to Audacity, with Y slitter cable connecting interface headphones output to audio line in of guitar amp and then connecting headphone jack of guitar jack to guitar hi Z input of audio interface while I was playing a YouTube video, and then the interface got really hot (oh no:( ) and I heard no audio so I shut it off imediately.

It appears that its not a good idea to connect a line level to a guitar hi Z input on an audio interface, or else the interface gets really hot and no audio is heard.


What about connecting a line level to the lo Z mic input of the audio interface? The lo Z mic input already has 48 volt phantom power that can be turned on and off, so I imagine that since it can handle 48 volts it should be able to handle line level with no problems. I imagine that I should turn phantom power off so I don't destroy yet another electronics device.


Edit: Now when I looked at my guitar I saw that the black wire had become disconnected from the output jack and that was the cause of me not hearing my guitar playing, but the line in connected to the guitar input jack was still not heard so I'm guessing the line in tripped an over current circuit that won't let too much current pass but will still allow weak guitar signals to pass.

I know that the cable has nothing to do with the problem because the cable would send my guitar signals before the guitar jack had the black wire come loose at the same time as not send the backing track.

Maybee I'm just being an idiot and the headphone jack of a guitar amp won't send you the backing track when you have an audio line connected to the line in jack of the guitar amp.


Edit 2: I tried the same setup except connecting the headphone jack of guitar amp to headphones instead of the guitar input of the audio interface and now the backing track is heard.

So it appears to be a problem with the interface not liking (getting very hot and giving up) a line level signal into the guitar input jack of the interface.
 
Last edited:

dietermoreno

Dec 30, 2012
238
Joined
Dec 30, 2012
Messages
238
Never mind. Retard question.

It has nothing to do with impedence level, it has to do with the mic pre amplifier has to amplify a much weaker signal than that produced by the guitar, so using the mic pre amplifier of the audio interface is an even worse choice to record a line level signal than using the guitar input of the audio interface.

Solution is perhaps to use an antenuator and a Y splitter cable. I'll ask about using an antenuator on UG forums since they have some guitar electronics experts on those forums.

Either that or give up and mic amps instead of connecting a cable from the emulated speaker jack of the guitar amp to the guitar input jack of the audio interface.
 

BobK

Jan 5, 2010
7,682
Joined
Jan 5, 2010
Messages
7,682
If you have a line input, and you need 2 line inputs, just make the world's simplest mixer. 2 10K resistors, one side to each input signal the other side to the signal side of the input, all 3 grounds connected together.

Bob
 
Top