GPSS-650: Are there any audio FX on board? Channels 1 & 2 are equipped with an adjustable ECHO effect. Product: GPSS-650 Related articles GEM Series: What is Phantom Power and how do I use it? [GPSS-650] Does the speaker have LED Party Lighting? GPSS-650: Is there any difference in the GPSS-650’s functions with unit plugged in to battery vs plugged in to wall? GPSS-650: Can it handle outboard floor pedals such as chorus, phasor, compression/sustain?