In Stock. 45 Day Lowest Price - 100% Satisfaction Guarantee. The anniversary Hot Driven Boost MK3, featuring a complete new overdrive design that gives a even more authentic tube simulating overdrive than the original HDB, which is known to be one of the best. The new HDB MK3 sounds like a tweaked up quality tube amp, and it does not change the original tone, has no midrange pronouncement and no low or high end cut off so that you get the tone of a clear brilliant tube drive.