Here's 15-year old Nic Clark of Denver CO getting monster harp tone through a STOCK Fender Deville 410 amp. No mods to the amp; it even has the stock 12AX7 preamp tubes. Nic is playing straight into the amp with no pedals, no delay, nothing. He is using a vintage Astatic JT-30 Crystal mic.
If you haven't heard Nic and his band lately, they are sounding outstanding. They'll be in Memphis in February for the IBC competition, and I expect them to do very well.