You will need fudge a bit, because they made sooooomany different models...
However what you have there is one of the first guitar amps, historically speaking.
I recognize the original cabinet but it's been recovered...
At the time, there were no efficient loudspeaker magnets, and loudspeakers were quite heavy because of the iron magnet.
In the mid 1930's the idea popped up to route the high voltage through a field coil, and the coil was an electromagnet for the speaker.
The coil basically replaced the choke of the amplifier. This magnetized the speaker frame, and a lightweight speaker became possible.
I can't tell if your speaker has the extra coil from the photos..but it looks similar.
Anyhow, at that time, Rickenbacker had invented the first single coil pickup, and it was sold on a frying pan shaped guitar.
Suddenly, lap steel guitars became amplified, in the late 1930's. Rickenbacker probably made the first guitar amp, soon followed
by Valco. The first Valco amps appeared in the early 1940's. I have worked on two that were built in 1941. But this was not the first
Valco Model (the 51). There was at least one previous Valco model which I have never seen in person.
Leo Fender worked for Rickenbacker as a technician at the time of the first guitar amp. His first amp showed up at least 6 years after
the Valco guitar amp went into production.
Therefore, Leo DID NOT invent the guitar amp. What you have is an amp that probably predates Leo. However it also looks like it was never
finished. There were no 1/4" jacks at the time, and your amp probably had the jacks added at a later date.
That's what's cool about it, it looks like an unfinished Valco prototype.
So anyhow on your amp, the output tubes ARE the phase inverter. There is no dedicated phase inverter tube. This indicates that it is
a very early model, I'm guessing 1940. This may be the first model Valco amp, that was never finished. I have never seen another one like it.
But I have seen the schematic to it.
And so, long about 1940, Valco shoots off to produce amplifiers in Hawaii. This was the Oahu amplifier, that is the same as the Valco, except
that it has a palm tree stenciled on the grill cloth. (very cool looking). Exactly the same amp, with a different nameplate.
