Hello, guys! I've played through a TE GP12SMX and through a Hartke HA3500 with 4x10 and 1x15 hartke cabs. I am using my trusty Fender PJ with EMG's on it. Adored the sound and volume from both of them. Is there something I need to know about those amps in terms of hardware problems, maintenance etc. Best regards to all of you fellow bass players!