Bastardized 1962 Blonde Bandmaster

[aermotor]

Reporting back after some discovery. Got the filter caps changed out, new 3 wire power cord and some other misc done.

Fired it up and she works out of the box, here's what I found.

The 'Vibrato Pedal' foot switch on the back has been modified to indeed enable a new OD 'distortion' circuit as Reeltarded and dcribbs1412 said —absolutely wild. The added relay in place of the tube is what's switching the distortion. It appears—though not certain— Normal 1 being the most distortion and Vib 2 being the least, more testing required.

The front 'Presence' knob now acts as a sort of master volume for the whole thing. 'Intensity' is a secondary channel vol for the Vib channel that allows you to turn the main Vib volume all the way up and drive it into the intensity volume for as much distortion for the desired effect.

That's the main discovery, and as weird as it is, it's pretty trick. Old timers modifying their gear to get their own sounds. Vibrato circuit is gone in its place, but that's a worthy sacrifice for now.

After hearing this and understand a bit more it's clear what the intention was, and I can appreciate it. Going to leave it alone for the time being and get some play time in on it.

Secured an early 60s blond 2x12 cabinet I will get outfitted and hooked up to it as well.

[Stevem]

It’s very good to hear that you did not just condemn it and take a wrecking ball to it.

Someone who might had passed on put a lot of thought and time into that.

[sluckey]

The added transformer in place of the tube is what is driving the distortion.

That metal box that replaced V4 (p/o vibrator circuit) is NOT a transformer. It's a RELAY.

[aermotor]

It’s very good to hear that you did not just condemn it and take a wrecking ball to it.

Someone who might had passed on put a lot of thought and time into that.

Haha yea, it was good to at least get it fired up again to understand a bit more what was going on. Ideally I need someone to trace out a schematic on it.

The added transformer in place of the tube is what is driving the distortion.

That metal box that replaced V4 (p/o vibrator circuit) is NOT a transformer. It's a RELAY.

Yep my bad sorry lol

[dorrisant]

Welcome to the forum!!

If you are willing to post a few more pics as the conversation goes, we could help to cipher a schematic from that and what is already posted. Are you comfortable with taking some voltage readings, or resistance measurements? If so, you have plenty of good eyes around here that do that sort of thing for the fun of it. I'm sure others would agree.

[aermotor]

I would love to do that, just let me know what specific more photos and where to check voltages.

[dcribbs1412]

The 180k/3.3M (with small cap) resistors are different from 180k/1M in original Gen2-3 as is the 100k/82k PI
56k NFB resistor?
Any sort of sound clip would also be nice if possible.

[dorrisant]

I would love to do that, just let me know what specific more photos and where to check voltages.

Straight(er) shots of the components attached to the pots. Also, some of the ceramic caps and ODs are not clear because the pic is shit from directly above. Maybe skew to the side so we can see the values.

[aermotor]

Got it on the photos, I'll take some more.

New question, in the power filter cap section, I'm noticing a 27K was removed and replaced with a jumper, and the other values are not factory.

Should be 27K, 27K, 4.7K, 27K but its currently 4.7K, 27K, 6.2K, Jumper — Do I put those back to factory values, or is it like that due to the removal of a tube and other mods that were made?

[sluckey]

Should be 27K, 27K, 4.7K, 27K but its currently 4.7K, 27K, 6.2K, Jumper — Do I put those back to factory values, or is it like that due to the removal of a tube and other mods that were made?

LET IT BE! The jumper is because of the removal of the vibrato circuit. This is no longer a 1962 Blonde Bandmaster. The person that did this extensive mod knew what he was doing.

[ampdan]

This is no longer a 1962 Blonde Bandmaster. The person that did this extensive mod knew what he was doing.

That's indeed a shame. As someone who was buying/selling this stuff in the 70's-80's, when these mods were made, this was already a desirable amp.
Yes he did. It's the implementation of the mods...

[aermotor]

Should be 27K, 27K, 4.7K, 27K but its currently 4.7K, 27K, 6.2K, Jumper — Do I put those back to factory values, or is it like that due to the removal of a tube and other mods that were made?

LET IT BE! The jumper is because of the removal of the vibrato circuit. This is no longer a 1962 Blonde Bandmaster. The person that did this extensive mod knew what he was doing.

Yep good call, thanks again. Definitely not a BM anymore haha.

This is no longer a 1962 Blonde Bandmaster. The person that did this extensive mod knew what he was doing.

That's indeed a shame. As someone who was buying/selling this stuff in the 70's-80's, when these mods were made, this was already a desirable amp.
Yes he did. It's the implementation of the mods...

I truly wish it was factory as well.