When you don't have anything plugged into it and the loop is engaged, why does the return knob make the amp warmer when i turn it up and get brighter when i turn it down, and why does the send knob act as a wattage control of sorts? All i've really known about effects loops because i don't use them is how to plug the pedals in and that it goes after the preamp to not interfere with the tone and what not. It's really awesome, i sadly just noticed this today and was wondering if someone could explain why it works like this and if the send knob is actually working as a wattage control type thing.
The send knob is a buffer, so if you don't have anything hooked into it the buffer acts like a boost, and the return knob acts a little like an attenuator (or vice versa, i forget how Mesa configures it).
Alvarez dreadnought
Gibson SG
Homemade Strat (seymour duncan classic stack p/ups)
Vox Tonelab (original desktop model) with full board footswitch
Vox AD50
Avatar V30 4x12 cab