How do you have the EQ set on the ME50B? If I'm not mistaken, the ME unit has an acitve eq meaning that you can boost and cut a particualr frequency. Most amplifiers have a passive EQ meaning that you can only cut frequencies, but not add. From "0" on down (ie. negative numbers), an active EQ is cutting frequencies as if it were passive. But when you go above "0" (ie. positive numbers) you are boosting a given frequency. Have you considered bypassing the amp's pre-amp and just run the ME unit direct to the power amp? You can use the unit's expression pedal as a volume control. Or if you like the sound of the amp, you can turn the EQ settings off on the ME unit unless you want to create a totaly unique tone for a solo or some other specific application.
