Greetings. I own both- GK MB200 & MB500.
Great amps! Got to learn how to set the amp to get a good sound on BG or UB with cabs, usually with a Markbass 2 10 or 15.
Only used the MB200 a few times-bought it as a backup when it came out after reading posts on TB.
(Also recall reading that many MB 200s were overheating & not working, so I was reluctant to use the amp.
I usually bring another amp head- Amped PF 350, which fits in a bag with cables.
Coincidentally, also read the same about the Ampeg head on TB. Thank God-Good so far.....
Never liked the sound of the MB 200, but, after seeing the recent posts, used it last night on a River Boat Jazz gig with the GK NE0 112 cab, 1940 Kay, Underwood PU & Zyex strings.
Totally surprised at the tone quality, especially without a preamp.
Much better combo with the cab & amp setting.
So glad I read the posts.
Who knew?!!