I had a Fender Bassman 100 top for several years when I lived back in England. It was a very powerful amp, but a bit "clean" for blues harmonica. I never got around to experimenting with different valves/tubes though. I liked it... I used to run it through two 2 x 12" speaker cabinets. As with any amp, "try before you buy". John "Whiteboy" Walden Cebu City Philippines