One of my customers offered me this Alamo Capri as a “partial payment” for some work. It didn’t work at all, and was in really bad shape internally, but the cabinet and grill looked good. And, more importantly, the transformers and tubes were good! This is one of the old “line voltage” amps that use a 12AU6 preamp, 50C5 power, and 35W4 rectifier. But, unlike most of these amps, which are typically referred to as “hot chassis” or “widowmaker” amps, Alamo used an isolation transformer so that the amp is safe. (The transformer even has a 98V filament tap, so you don’t need a resistor to dump-off the rest of the voltage.)
Here are some “before” pictures, showing the sad condition of the circuit when I received it:
I decided that I was going to be keeping this amp for my personal collection. I completely disassembled the chassis, cleaned it, neutralized the rust, and started rebuilding. It got a 3-prong cord, and a mains fuse. I moved the power switching off of the tone pot, and added a toggle and status light. (Having the power switch on the tone or volume pot is a major source of buzzing.) I was able to clean and rebuild the original pots, and with the power now moved, I had a switch available on the tone pot. I wired it so that you can completely remove the tone pot from the circuit, giving you a little bit of “raw” boost. The old tube sockets were disintegrating, so they got replaced with “period correct” porcelain 7-pin sockets. I tried to use as many of the original components as possible, but a few caps had to be replaced. Also, I didn’t foresee ever plugging in 3 instruments at once, so reducing it to only one input allowed me to use a shunting jack, so the input grounds when nothing is plugged in. Sadly, the original speaker is in very poor condition. So, for the time being, it has a Jensen MOD speaker installed. I may someday re-cone the original, or find a more suitable replacement.
Here are the “after” photos, including a new handle, and some old-stock knobs I had around:
It is a great sounding little amp! In fact, it recently made its way into the recording studio with me, and will be all over our forthcoming EP.