I have problem whose solution is probably simple, but I can't seem to solve it. I am trying to record a guitar track into Logic (10.7.7) through TH-U amp sim. The input level sounds fine from my interface, but I can't hear sound through TH-U in my headphones (the TH-U level in indicator shows no input). The channel input is correct, track is record enabled and monitor selected. And I can record the guitar in the track, and the playback sound from TH-U amp sounds fine. I just can't hear the amp sound as I record. TH-U standalone also sounds fine, all audio in and out settings are correct. I just cannot hear the amp in Logic. I have the same problem with two other amp simulators I own (Tonex and Amplitube, standalones work fine, but no sound in channel, although recording playback is ok.)
I feel like I'm missing something very easy in Logic to get input into the amp sim to hear it as I play, but I can't figure it out. What am I not doing? Any help much appreciated.

 

You have to understand the signal flow in Logic. The signal is recorded in Logic before it even hits your plugin, so your guitar is probably just being recorded dry. This is why many musicians and singers use interfaces with DSP (like UAD) so that the effects are applied and recorded as the signal flows to the DAW with very low latency. Signal flow goes in to Logic's channel to the fader, and then travels upward to your plugins, and THEN goes down.

I would look into two things. First, if you put the effected signal on a Bus and record the output of it into a new track, you will capture the effects. Also, I would look into how to setup a Headphones Bus in Logic. That way you can send any mix you want to your headphones to monitor as you play.

As you have 3 plugins all doing the same thing, it isn't a problem caused by the plugins. It is a problem with your signal flow and routing. I don't play guitar or use amp sims, or I would answer more concretely after a test. Do a YT search for "Logic headphones bus", but here is one from Chris at Why Logic Pro Rules. It covers this pretty well:

 

Last edited: Mar 6, 2023

Thanks for the detailed reply. I tried your suggestions and learned some things about bussing (although I never had to do this in the past). I found a solution though - editing the Logic control bar and enabling software monitoring (I don't know how it got turned off, and I'm too much of a Logic novice to have noticed). I really appreciate your help.