NAD 1954 Fender 5C7 Bandmaster

ooops...no schematic

 

Very VERY cool Congrats!
And as @RoscoeElegante said already: we definitely need sound clips when it's been checked over by a tech.

 

Holy Mother of Bejuuviah! Dream amp! No experience with a 5C7 but: (a) go by tech before really putting it to use; (b) treat it well; (c) play it, play it, play it. Congrats!

 

I looked in Weber's book- no 5c7, but there are 5c8 and 5d8 Twins. Both appear to have bass and treble. 5d8 has miniature preamp tubes - 12ay7 and 12ax7, so maybe it is closer? The 5D8 appears to have baxandall tone control, which would probably work better than anything that came after since there can be a boost or cut.

 

Cool, but what's with the black tape on the wires in the last pic?!!!

That doesn't look safe, surprised no one else noticed or commented?

 

Replace the power cord with a semi-modern one...without the funky colors. Cut the death cap (the big red one in the last photo) out (or at least cut one side of it so it has no connection to chassis ground...maybe leave it in place and just shrink wrap the cut lead.). Check what's under the electrical tape, it looks old.

 

...and get rid of the desiccant pack....

 

Congrats. That hole through the top of the chassis would be a big hit on value for me. I agree with Charlie .chitlin that that was a crude approach. as for a schematic, I am going to take a wild guess that this amp is very much a 5D7. It runs 12A-7 tubes instead of the octals used in the earlier amps. For a schematic, look to the Pro 5D5schematic. I suspect you will find it is very similar to if not identical to the 5D5 Pro. out of curiosity, what is the serial number? This may be a 1954 amp with an earlier 5C7 tube chart.

http://www.ggjaguar.com/fendamp5.htm

 

Yeah, I would put that amp through a thorough evaluation. Those paper in oil caps are not good at this age, ime. And....I would advise checking every resistor in the circuit. I have seen huge deviations from original values in these old amps. I had to replace every resistor on the board in one 5B5 Pro...and it sounded glorious after all was done. Don’t worry about the originality of the board components. Imho, those components are like spark plugs...they need to be changed. And...again...that hole in the chassis is much worse than replacing board components when it comes to value.
I suspect that the AC wiring should be redone. Is that blue neutral wire bared...damaged insulaiton? It seems to me that the work done was done in a very amateurish manner. Get it made correct and enjoy.

 

And...regarding the E series Fenders. Those amps have very little in common with the earlier amps outside of tweed covering, speaker configurations, and model names.

 

Fantastic find! That tweed looks pretty damn good. Are you considering vintage glass for your new baby? Enjoy.

 

https://el34world.com/charts/Schematics/files/Fender/Fender_pro_5c5.pdf

Your schematic. Pro/Bandmaster/Super...all the same except for the speaker layout, I think.

 

This schematic will be very similar to the OP’s Super with the exception that the 5C_ amp’s run octal preamp and phase inversi9n tubes rather than the 12A-7s we see in the pictures the OP gives. The OP’s amp is not a 5C7 despite the tube chart. Those tube charts do NOT define an amp as we all know from experience. Ex: I have owned a mint 1957 5E3 that had an original t7be chart.....for a 5F6A Bassman. The circuit and tubes define the amp as far as what schematic is to be trusted.

 

That 5C5 schematic only has a simple tone control, not bass and treble contols. Also has 4 inputs, not 3.

And, I have been remiss in congratulating the original poster. This is a great find. I am very interested in the corcuit and tone since this is a predecessor to the great 5E7.

 

This will ime be the circuit in the amp the OP has.
https://schematicheaven.net/fenderamps/pro_5d5_schem.pdf

Note the 12A-7 tubes, and remember that we can see the 12A-7s in one picture the OP gives us. As for this amp or a true 5C7 being a predecessor to the later 5E7 Bandmaster, that could be said of any of the big tweeds from 1954 on back. There was not much variation between those models but for speakers. pin fact, the 5D8 Twin is a closer relative to the 1955 and later 6L6 Fender tweeds in that it is the first to have both a treble and a bass control...with everything else being very much the same as the Contemporary Pro/Bandmaster/Super amps.
Picture #4 on the first page is revealing. Note the cathode bypass circuit for V1. That indicates a 5D- circuit. The 5C5 has a grid leak bias preamp. Get a good tech to evaluate this amp, Bloozeguitar. And....again...what is the serial number? If this ap was built in 1953, it will be a very early 5D7....since the Day indicates a schematic that was not drawn until 1954.

 

Wow , what a find! Very cool. I'm betting that amp has been recovered. The tweed doesn't look right. But no big deal!

Did the Bandmaster ever have a separate control panel and the amp in the bottom of the cab like the Bassman did in 53?

 

Some of the early amps had vinyl instead of tweed, I wonder.... I had a 53 Bassman for a while (amp in the bottom of the cab, control in normal location up top) It was vinyl covered.

 

Not quite, 5C7 has separate tone controls.