A 1950's Valco Tremo-Tone

This is a very cool Valco Tremo-Tone National Model 1224.

It has a pair of 6V6's with a 5Y3 rectifier, and octal preamp tubes: two 6SQ7's and a 6SC7.

The owner stated that the tremolo worked for about a second after turning it on. He also wanted to replace the 2-prong power cord with a 3-prong based on my comments about safety.

Although the bone white handle looks like a replacement, it matches the white control knobs.

This amp has been through some rough times, but that is a sign of character.

Check out those 6x9 speakers, which are usually found in automobiles!

Those pink Sangamo coupling capacitors give these old amps a unique "woody" or "grainy" tone that's almost impossible to replicate with modern components.

It turned out that one of the coupling caps in the tremolo LFO had gone bad. Most likely it was the one on the lower right between the terminal strip and tube. I also replaced the two on either side of the terminal strip. These are not in the signal path so the amp tone was preserved.

Working on vintage amps like these takes a unique approach. Although many would recommend replacing all of the coupling caps and electrolytics, this would change the tone dramatically. When possible, it's best to leave everything in place.

As with modern amps, sometimes everything in these amps can break down at the same time. That's when a complete overhaul is justified.