Questions & Answers

Can I use Aux In a/b to connect an external mic preamp?

0 votes
asked Apr 11, 2017 in Ai Mixers by dtrader (160 points)
I want to connect a 2 channel (mono) mic preamp (ART TPS II) to my 16.4.2ai mixer through the Aux In A/B channels.  I have set Aux Routing so that Aux 19/20 is aux in a left/right and Aux 20/21 is aux in b left/right.  Channel 1 from mic preamp (mono) is connected to left of aux in a and Channel 2 from mic preamp (mono) is connected to left of aux in b.  My thought was I get 18 channels of input, without the need of a patch panel or the external mic preamp going through channel 1-16 pre amp.  I use the board to record only, no live shows.  My monitor mix for artists is AUX outputs 1/2 (stereo linked in pre2 mode) to inputs (L/R) of head phone amp.  I use the CR outputs for control room speakers (solo mode CR) and Mains Out L/R for live room monitoring.  The problem I have is a "latency" or "delay" in headphones, only on the Aux In A/B channels.  The digital returns from computer on for channels 1-16 are fine when a mic is used to record vocals on channels 1-16.

I use the board as an interface at 48khz/24bit, monitor mix for headphones during recording, UC 2.0 to control monitor mix on PC screens and fat channel for gates and HPF.  Even with all fat channel features off the problem exists.  I have pro tools 12.7 and have used the pro tools template (PT-SL16.ptt) from Presonus with no luck.  The 16.4.2ai firmware is 1.0.9194.

Curious to know if there are others out there using this mixer for recording and what sources they have used for setup info.

1 Answer

+1 vote
answered Apr 11, 2017 by wahlerstudios (104,880 points)
selected Apr 11, 2017 by dtrader
Best answer

You can record one more stereo track (16+2), which needs to consist of paired channels. Therefore you can use either Aux In A or Aux In B, but no combination of both. But this should work for feeding (line/symmetric) signals to the main or headphone bus. The delay probably comes from the A/D conversion of Aux In's and where it is situated in the signal flow. Normally the Aux In's are used as returns of external FX machines or for time-uncritical audio feeds. As "expansion" of  input channels they have always been unsuable.