Today was fun. 3 silver panel Fenders and a blonde. All of them were a hot mess of craptastic tech work! Poor soldering, poor choice of components, general laziness.
The best was this 1963 Bandmaster......
These are one of my all time favorites. They're genuinely weird amps in the Fender canon. With active tone controls that people largely rejected and that lush absolutely glorious 3 tube harmonic vibrato that was likely quite expensive to produce. It sounds closer to a Univibe than what any other Fender produces. It's got a phase shifter quality. Not like the pitch bending Magnatone, it's just a shade subtler.
These amps used to be cheap as chips. Not any more, yet they aren't all that popular. People prefer the tweed and black series, these are just, odd. I bought one for $300 in 1991 and played it with a JTM45 together during the Grunge Scare of the early 90's. Big tone!
So this one was a mess. Just general poor tech work on the inside. It was re-capped years ago. I re-did the electrolytics. The whole thing was Orange Dropped. Not my favorite but since I was on a budget I let them be. Besides, most of them were the old polyester series which I like very much. Only a few were the 715 series.
The choke and output transformers are replacements, the choke being from 1966 and the output transformer is from 1972. Not the least bit unusual on this model. I've seen more Bandmasters throughout the whole range that had bad output transformers and a handful with bad chokes. I think they were just a hair under rated, but that's part of what gives a Bandmaster it's special sound. These parts were likely replaced years ago as this amp has been around the country making music. It's had a life and a half!
So once I got the basics done I noticed the obnoxious "thump thump thump thump thump" of the vibrato system hadn't gotten any better. Simple fix. One of the cathode bypass caps in the circuit was supposed to be a 2uf cap. Someone upped that to a 10uf cap. The tremolo circuit in any amp can be very sensitive so it's best to go with the original component values. Problem was solved right away.
Sometime it's a bad tube that causes this, or a bad cap or resistor. Today I was lucky. No time tied up in trouble shooting mode.
But..... while I love the tone quality of the vibrato in these amps I wasn't satisfied. It was just to fast. Not enough range. Rather boring. Simple mod took care of that.
Locate the 3 caps in series that create the oscillation. On the plate its .02, the other two are .01. I simply doubled the 3rd cap by placing another .01 cap in parallel to the one connected to ground. First try it out:
You can try different cap values here and if you like it cut those leads and give it a permanent home:
Not a bad idea to do it this way rather than replace the original component so if down the road you want to remove it there ya go!
Anyhow, this one is making music again and is for sale at Southside Guitars here in Brooklyn. It's a fantastic amp. Player grade yes, but you're a player right?
JB
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