Re: Problem with my Laney GH50L
i have this head as well. totally agree with van noord that the low input is the key to getting less fizzy tone. there is less gain, but the foundation of the amps tone becomes more full sounding or more vintage. it's ideal for ac/dc type gain and provides a good basis for a tubescreamer or o/d pedal of your choice to drive to higher gain without the fizz.
additionally, what volume level are you playing this head at? this amp is definitely not what i would call a bedroom amp; it's ideal when used with a band in band practice and gigging situations because like most tube amps, it sounds best when the power amp tubes are overdriven. if your volume is lower than 4 (which is pretty f'n loud), then that probably explains the fizziness.