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Post subject: Blackface Bandmaster Pre CBS/CBS Question
Posted: Fri May 30, 2014 10:25 pm
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Ok I just picked up a 65 Blackface Bandmaster that is in really good shape from my local guitar center SN#A111590.. I did a ton of research but I haven't found anything on the fact that the front of my amp it says Fender Musical Instruments which is not in question and is correct of the research I have done as the front plate was changed after CBS took over.. But I've compared mine with several pre cbs amps online and on the back plate it matches the pre CBS and has Fender Musical Instruments Co Fullerton Calif Made in U.S.A. As to the cbs models shows Fender Musical Instruments Santa Ana Calif Made in U.S.A. Is this a fluke? Or did I find some sort of transitional or in-between the pre cbs and cbs era? Kinda cool I think!

Pooch


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Post subject: Re: Blackface Bandmaster Pre CBS/CBS Question
Posted: Fri May 30, 2014 10:33 pm
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A pre-CBS panel -- front *or* rear -- would be marked "Fender Electric Instrument Co."

The variation you've noted is nothing extraordinary -- CBS accouterments appeared in several different incarnations.

Arjay

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Post subject: Re: Blackface Bandmaster Pre CBS/CBS Question
Posted: Sat May 31, 2014 6:26 pm
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Ok so what your saying is that it's not that uncommon to see this on CBS amps? What's the real significance between the AA and AB circuits? And how would I know which is in the amp I have?


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Post subject: Re: Blackface Bandmaster Pre CBS/CBS Question
Posted: Sat May 31, 2014 8:00 pm
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Shortly after CBS purchased FEIC (who then renamed it FMI) they built a new corporate sales HQ office in Santa Ana, which accounts for the marking difference with the later CBS-era amps. This new administrative suite was up and running sometime in mid/late 1966 but the production facility itself remained in Fullerton.

The principle difference between the AA763 and AB763 Bandmaster revisions lies in the resistive feedback network going into the phase-inverter's cathode wiring. The AA specifies a 27KΩ resistor, the AB a 22KΩ. The cumulative effect on tone is minimal although the AB configuration remains cleaner at max design power.

Arjay

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"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKY


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Post subject: Re: Blackface Bandmaster Pre CBS/CBS Question
Posted: Mon Jun 16, 2014 11:07 pm
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Ok..

Got another quick one for you about this amp... I have found V1 to ring when I tap the tube... I switched tubes with three different ones and the result is the same.. Is this common with these amps or is there a real issue at hand?

Pooch


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Post subject: Re: Blackface Bandmaster Pre CBS/CBS Question
Posted: Tue Jun 17, 2014 1:33 am
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It would seem you have a microphonic component somewhere in the vicinity of the V1 socket. The last time I encountered this pesky symptom it turned out to be the ceramic disc cap wired to that channel's bright switch.

Time to break out the chopsticks and go a-tapping.

Arjay

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"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKY


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Post subject: Re: Blackface Bandmaster Pre CBS/CBS Question
Posted: Tue Jun 17, 2014 8:12 pm
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IMO...If the the amp plays well and has no ringing, I'd leave it be. It may be a future issue, if the condition imposes itself on the signal. Just remember, tubes and components are not meant to be tapped. I've had tubes and components that don't like physical tapping. But they play very well and are open sounding. Again, JMHO, Art

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Post subject: Re: Blackface Bandmaster Pre CBS/CBS Question
Posted: Wed Jun 18, 2014 5:45 am
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CBS bought Fender in 1964 so a 1965 amps is a............ :lol:


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