Flooded 6G7A Bandmaster Rebuild

[gldtp99]

Pics: http://s46.photobucket.com/albums/f112/gldtp99/Fender%20Bandmaster%206G7A%20Flooded/

Bought this '62 Bandmaster inop a while ago---i didn't realize that it had been in a flood and needed a complete disassembly/cleaning and rebuild until it arrived----- orig iron ruined, a nasty stinking mess.
New Magnetic Components PT and 4/8/16 ohm OT, Hammond choke----new cloth push-back wire from Doug Hoffman (other parts, too--- preamp tube sockets, etc, etc).
All Sprauge Atoms under doghouse---i used two 100uF/350V in series, with 220k balancing resistors, for the first filtering stage instead of the stock pair of 20uF in parallel----a couple of 27k power rail resistors changed to 47k to adjust preamp voltages to spec----- 6L6GC plate voltage is 465V.
Amp had yellow Astron caps on the board---i saved them for future projects when i stripped the board for cleaning/rebuild-----i didn't want to use the Astrons in this player rebuild---- used mostly Mojo Dijons (i had them on hand) and i'm glad i did---- the amp sounds great---- i had to use one OD 715 because it was the only new .033 cap i had- -- it looks out of place on the board.
One friend who A/B'd this one against my #1 best sounding orig 6G7A Bandmaster (i have four including this rebuild) liked the rebuild over the orig one---- the Harmonic Vib on that orig 6G7A is extremely strong and can be overbearing so i think he liked the rebuild's Harmonic Vib better--- the amps sound very similar with Vib off.
The Harmonic Vib is a phasey, swampy load of fun to play with....................gldtp99

[stingray_65]

WOW that looks great!

Did you have any issues with the wood in the cab or baffle board? or the tolex peeling up?

It makes me happy that a nice blonde like that wasn't parted out and lost forever.

Great Job!

Ray

[gldtp99]

Thanks--- i had to glue many tolex edges----i used lots of lysol (many applications) on the wood to get rid of the mildew/musty smell.
I had to take everything apart down to the bare chassis and clean flood water residue off of everything--- used Magic Eraser on chassis-----scrub brush, toothbrush, rags. Dishwater, Windex, QD Electronic Cleaner, Caig D5, and Caig MCL---all orig pots and jacks on front panel cleaned up well and were re-used. Back panel jacks and switches are all new. Eyelet boards stripped, cleaned, and rebuilt.
It doesn't look or smell like it was a flood survivor now...................gldtp99

[Underwood]

 I am looking at you bias circuit and am interested to know the values of the caps and resistors you used. Also, the bias pot. 10,25,50K? I am redoing my bias circuit on my 62 bandmaster.  It was screwed up when I got it.  Thanks for any help!!

[gldtp99]

25k bias pot---- 22k bias resistor (to ground)----- 15k between bias caps (the metal film resistor)---- 10uf/100V bias caps.
These values work with the replacement PT and the used pair of Sylvania 6L6GC's-----i started with a larger (don't remember exact value) bias-to-ground resistor and changing to 22k brought it within range--- adjust yours as necessary......................gldtp99