JSF... you're right about those "big amps". They are nothing but
hay-wired prototypes, mostly designed and constructed by persons having
no electronic background. I have looked at many of them over the years
and have found that they have major flaws such as inadequate cooling,
improper tuning, and instabilities/oscillations caused by improper
layout and long wires running around all over inside. Because of these
issues, their owners must keep a steady stream of expensive output
transistors flowing through them... if you know what I mean... LOL

www.telstar-electronics.com