Can I use unbalanced leads in mixer inserts (direct recording)?

uncleswede

New member
Post title kind of says it all...

I was planning on multi-track recording a live show last night, feeding direct, mono signals to the recording set up from the FOH mixer inserts, but hit a snag....

I connected an unbalanced 14in jack/XLR cable loom to the FOH mixer inserts (not my mixer), inserting the jacks just to the first position so as to tap off the signals without disturbing the main outs, and then to a Tascam US-1800 unit USB'd to my laptop running Reaper v5

I could see signals hitting the Tascam channels as the stage crew were setting up/plugging in but then they had a peculiar problem with one of the two Aux Send channels having a lot of noise on it. They thought it was the monitor and swapped it out - noise still there. Various cable/power-lead/power socket changes later the noise remained.

It wasn't until I disconnected my loom from the mixer inserts that the noise vanished!

I have no idea what was causing the noise but it occurred to me that, even though I only want to tap off mono feeds from the mixer inserts, I might need to use balanced cables?

Anyone experienced the same issue and have a solution for me?

Many thanks
CD
 
I connected an unbalanced 14in jack/XLR cable loom...

How was this wired? I assume from the context that the 1/4" ends were unbalanced. So how exactly does it get from the two conductors to the three conductors?

This is my standard reference regarding balanced/unbalanced interfacing: Sound System Interconnection

No, you don't need to connect balanced to most common TRS send/receive inserts. They are two-way unbalanced. Larger consoles often have separate send and receive XLR connectors, but that's probably not the case here.
 
What you did should have worked. I have no idea how it would only cause noise on aux 1 and 2, without the noise going to the mains. If the noise was everywhere, I would assume a ground loop. (Assuming it was hum)
 
I always do this by soldering the jacks and linking send and receive in the plug, and then inserting it fully. It's possible you lifted the normalling in the plug with the trick of a half way insertion. Fully home is my method, and always worked for me.
 
I would guess a ground loop between the computer and the via the mixer.

Ground loops turn up everywhere, sigh! I carry isolators, and ensure that the gear is all on the same power feed and the same phase. If you do what was suggested and link within the jacks, you could drop the shield off at the US1800 end of the cables?

If you ran the laptop on the battery the noise may have gone away?


Alan.
 
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