The Fender Connection
Kalamazoo - a Less Expensive Tweed Champ?The Kalamazoo Model 1 and Model 2 (and hence the single 6BQ5 version of the Gibson GA-5 Skylark) circuits are almost identical to the Fender Champ 5F1 circuit (discounting the Model 2 tremolo oscillator), with slightly different component values. The main differences besides component values are minor:
- a Kalamazoo uses a 6BQ5 and 6X4 instead of a 6V6 and 5Y3
- on a Kalamazoo, only one jack shorts to ground when not in use
- a Kalamazoo's output tube has no cathode resistor bypass cap
- a Kalamazoo does not have a negative feedback (NFB) loop
- a Kalamazoo has a tone control (with a single cap)
- a Kalamazoo has a slightly smaller output transformer
- a Kalamazoo has a 10" speaker
Many people consider the 5F1 to be the best Tweed Champ circuit. With a 6BQ5 tube, a Kalamazoo is thus the best of both worlds.
Since the Kalamazoos were produced in the mid 60s, they were definitely copies of the Fender circuit, rather than the other way around. Either that, or they copied the same circuit Fender copied.
Of the other three GA-5 / Skylark circuits I'm aware of, one is essentially a Champ in Gibson skin. The 6V6 version of the Skylark is almost dead on a 5E1 Champ (again with slightly different component values, but this time with the same tube complement). The Gibson Les Paul Jr. amp is similarly a 5C1 (very early, pre-12AX7) Champ circuit. The two 6AQ5 GA-5 has no Champ equivalent. Neither does the version of the GA-5 with two 6BQ5 tubes. Nowhere can I find documentation that this dual 6BQ5 version exists, but several of them are floating around.
Last updated: 14 November 2007
Copyright Y2K Miles O'Neal, Austin, TX. All rights reserved. Miles O'Neal <meo@XYZZY.rru.com> [remove the "XYZZY." to make things work!] c/o RNN / 1705 Oak Forest Dr / Round Rock, TX / 78681-1514