Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: BrianS on December 23, 2015, 10:58:14 pm
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Howdy Folks!
I recently acquired an old Fender Bassman from a customer of mine. I had recapped this amp several years ago and told the gentleman that if he ever wanted to sell it to contact me first. He did, and I bought it.
Digging deeper into the amp, I come to find that it is from 1964, and looks to be the 6G6-B circuit. Here's some things I'm thinking of doing to the amp:
1)Adding an adjustable bias pot. I have the CTS 10k bias pots at my shop and am thinking that I can just copy the bias circuit found in the AA864 circuit.
2)Purchasing some "NOS" 5881 power tubes off ebay. Fairly expensive, but maybe worth it for this amp? Otherwise, what new power tubes? I've got some sweet old 12AX7s for the preamp, so no problems, there. Right now the amp has a motley crew of chinese and russian tubes from 15-20 years ago.
3)Purchase a headshell from Mojotone (amp currently doesn't have one). This amp has a black faceplate with the numbers on it. The knobs that were on the amp when I got it were "blackface" style knobs that covered the numbers on the faceplate. I got some Fender repro knobs that I think are more appropriate for this amp. Would it be appropriate to get the headshell with blonde tolex, or go with black? Kind of want the amp to look original, but that isn't 100% necessary. Just looking for opinions here...
Anyway, just looking for opinions and suggestions. Thanks!
-Brian
(https://lh3.googleusercontent.com/-CDeh0mepCEE/VntyFBX0-SI/AAAAAAAABwk/wBkKr0jYUM0/s512-Ic42/image2.JPG)
(https://lh3.googleusercontent.com/-of85EIQQMAc/VntyFIXJzVI/AAAAAAAABwc/-o7i9YFttIk/s512-Ic42/IMG_0485.JPG)
(https://lh3.googleusercontent.com/-SBCpHc4NtJI/VntyFVeLvaI/AAAAAAAABwg/eMcY0TbbWNY/s512-Ic42/image1.JPG)
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with those knobs i would go for a blonde :icon_biggrin:
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Have to say 90% Blond. Google images "6G6 Bassman".
Fender DID make Black Bassman amps black tolex black panel white knobs (non-numbered eg; old style, like what you have)
But if you have a brown panel, that indicates blond and nothing but blond.
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Did some Googling, as suggested by eleventeen, and found a few examples of black panel amps in blonde shells...think I'll go with that.
What about going with NOS or old stock, good condition 5881s? Seems reasonable. Any of you go for the old power tubes over the new ones?
I also see that some guys are modding the bias circuits of brownface amps to be adjustable. Sound idea? I guess the smart thing to do would be to get the tubes and see where they bias before adding any circuitry...
Thanks!
-Brian