Hey Dalto, thanks for your answer.
How can you set up on TWEAK mode then ? It will not switch by itself. Look at the table in the manual, there are "two" options:
- WAH/VOLUME with or without Pedal 2
- TWEAK with or without Pedal 2
Or maybe tweak mode is enabled if you use a footswitch instead of an expression pedal... dunno. You'll use it to switch between volume & wah on the onboard pedal... Anyway, tweak mode is not really interesting... (and I still can't understant what's the point with Tweak WITHOUT Pedal 2 ? What do we tweak here ????)
Most interesting option if you use an external expression pedal is probably 'WAH/VOLUME" with Pedal 2. You can use your expression for volume and keep the Wah on the onboard pedal -the opposite is not possible....-. Unfortunately, in this configuration, you'll have to activate/deactivate the onboard Wah with the Toe Switch (press hard with your foot). That's not conveniant at all. Every Wah pedal on the market switch automatically to the Wah sound when you juste move the pedal. With the onboard pedal set to Wah, you have to remember to press hard when you want to use it, and press hard again when you stop using it. That's really confusing.
Anyway...! --> I finally ended up using my Behringer Wah pedal on the FX loop. And I kept the onboard pedal for volume control only. That's probably the BEST (most simple) option for players who want to use volume + wah at the same time on the Firehawk FX.
TIP: if you use an effect pedal on the FX Loop, you need to move FX Loop BEFORE the amp in the diagram. Otherwise you'll have sound issues (insane clipping). Once the FX Loop is set before the amp, it sounds as it should.
Good evening
PS: Firehawk is otherwise a great product. Now that I managed to solve my wah/volume issue, I have a nice setup with everything that I need. All effects on Firehawk, and an extra Wah. I just built a little IKEA Pedalboard and it's great ;-) Here's a photo.