I have the option of picking up a used Fender TB1200. THe only issue with the amp, according to the owner, is that there is a slight "pop" through the speakers on turning on or off. He claims that he contacted Fender about this, who said it was OK, and was just capacitors discharging. COuld any owners of the 600 or 1200 chime in and let me know if this is normal, or should I steer clear of this particular amp ? It is at a very reasonable price.