I've been using this baby for a year and a half now and it has been a true lifesaver.
It's part of a nice large (and heavy :( ) board. It does channel/loop switching on the amp, MIDI control over 4 effects.
Although everything looks complicated it actually made my life easier as I'm a guitarist/singer and simply can't tapdance too much on the stage. After I programmed it that is.
That part is somewhat complicated as there's no display or GUI, everything's done with switches. Unless you're smart and connect it to the computer via usb and do the programming in their software :)
It has a built in power supply in two isolated 500mA sections. I use these to power my analog pedals. One section is powering the pedals in front of the amp and the other powers the pedals in the efx loop. If you mix them up beware, you'll probably get a ground loop hum.
The build quality is excellent. This thing is made to last.
I like the G Lab pedals because this one is quite innovative. While it is not the cheapest pedal around it has loads of features such as the loops for other pedals and of course the ability through midi (and other unit from G-Lab) to control my Mesa Road King II.
I also use this pedal to control my Kemper amp (they don't yet have a midi pedal) which needed a very flexible midi pedal. I chose the GSC-3 literally because of the above.
I have found that I can control lots of midi gear with the GSC-3 and like it. I'm considering a GSC-4 these days, as the GSC-3 is serving me well, but I also need another midi pedal...
I liked the three year warranty from Thomann and that's really the main reason for buying for them, but the prices are cool too mostly.
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