my favorite amp
early 1960's Jets had octal preamp tubes and a 6V6 power section
those have a creamy crunch sound like a Valco or tweed Deluxe, and break up early
mid-1960's models had 12AX7 preamp tubes and 7591 power tubes, and have more headroom
the problematic Jets are from the later years, when Ampeg was owned by Magnavox who used that model to exhaust their supply of "compaction" TV tubes
the 6BK11 preamp tubes used in those amps have not been produced since the 1960's, and remaining NOS samples are expensive
my newer Jet (J-12D) had that circuit, and the preamp tubes were failing
I had a tech mod it to the circa 1961 specs (J-12). 5 tubes and sockets, a few resistors and capacitors were required
the Reverberocket has a larger cabinet, dual channels, tremolo (with speed and intensity controls) and reverb
if you compare the Jet to a tweed Deluxe, the Reverberocket sounds bigger and cleaner with a warmer midrange that a black panel Fender