Here's a neat amp you don't see every day.
This is a 1959 Gibson BR-9. It belongs to a friend who graciously let me play around with it for a week.
The "BR-9" is also the model number for one of Gibson's 'student' lap steels. My guess is that the lap steel and amp were sold together as a package. That's the way my friend acquired it - both the steel and the amp.
Most notably is the fact that it's unusually thin in depth. Probably only about 5 inches deep, if that.
If you've been looking closely, you'll see there are no external exposed fasteners for the chassis and speaker.
The speaker is a Rola, with a date code of 1959.
Pretty simple - two inputs, one volume control and an on/off switch. No pilot light.
I wanted to open it up to inspect the insides. How do we do dat?
The chassis is bolted to a piece of plywood, which in turn is attached to the cabinet with four wood screws.
Undo the screws and the plywood panel and chassis slide out.
We have a 5Y3 rectifier, along with a metal 6SJ7 preamp and two 6V6s in parallel. For some reason, Gibson mounted the 6V6s apart from each other - they're the two glass tubes at the rear.
Judging by the 1997 date code on the can cap, it was serviced about 15 years ago.
It was also recapped and the volume pot was replaced. Whoever did the work did a very clean job.
The amp sounds pretty good. If it were mine, I'd probably put a more efficient speaker in it if I were going to use it a lot.
Tone wise, it tilts toward the clean, lower gain side like a lot of old Gibson amps. The 6SJ7 preamp tube has an amplification factor of 19, so you're not going to get a lot of distortion.
I found it worked great with the amp volume cranked and using the guitar's volume to control everything. The tone is nice and clean, with some light breakup when maxed out. It's nowhere near as loud as a Champ or Princeton of the same era, but it would make a great practice or recording amp.