The best way to view your TC-Helicon device, in relation to the PA, is as a complete mic channel with effects.
What that means is that you're doing all of your pre-amplification etc. at the TC-H unit, so when the signal reaches the mixer, it's more like a line level signal than a low level mic signal.
Here are the steps to take in order to ensure maximum gain before feedback when using a PA or Stick System like a Bose L1 etc.:
- Set the mic gain on the unit as per your manual.
- Set the guitar input (if applicable) so that it clips when you play your hardest, then back it off by a couple of db for headroom.
- Set the output level (Mix Page) at full.
- Set the guitar level (Mix Page) at full if you're using dual mono.
- Set the guitar level (Mix Page) to blend with your voice if you're using Stereo.
At the PA:
- Flatten ALL eq.
- Turn the input trim to zero.
- Turn off any internal/external effects for the TC-H device input channels.
- While singing/playing at full volume, slowly turn up the input trims until you are peaking at about -3db on each incoming channel strip.
- Now set the channel faders at 0.
- Slowly turn up the mains while singing/playing at your loudest.
- When you get feedback, turn down the mains slightly. This is your MAX volume for the PA.
- Mix the rest of the band in under the vocals.