It’s not the most exciting pedal in that it’s just a clever switch, but I do like the possibilities it gives.
It has two switchable loops. In one loop I have my Diezel VH4-2 working as a preamp and in the other I have my Peavey Classic’s pre amp. This allows me to switch between which preamp I want to use whilst also keeping my delay and modulation effects in the FX loop - post preamp.
Guitar goes in to the input. Red loop sends to the VH4 and returns from the VH4 preamp output. Green loop sends to the front of the amp and returns from the FX loop send. That’s the two preamp loops. The left switch toggles between each loop and the right switch bypasses both loops, which in my case means I have no preamp as the signal goes straight to the FX return via the delays - so I’ll keep the right switch always on.
Then the output of the pedal goes to the modulation and delay pedals and then to the amp’s FX return.