NAD (What have I gotten myself into now) Completed!

Steverino

Steverino

NO VACANCY
1966 Blackface Champ in the most pathetic condition I’ve ever seen. Can it be restored?

A Gorilla speaker! Oh lawd
 

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Oh and I just realized I posted this wrong pic of the innards. That pic is from the web, for reference.
HERE’s the actual pic of the circuit:
 

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Take a screwdriver and poke a bunch of holes through the Gorilla speaker. It will not improve the sound, but it could make you feel better. :baimun:
 
jrockbridge said:
Take a screwdriver and poke a bunch of holes through the Gorilla speaker. It will not improve the sound, but it could make you feel better. :baimun:
Click to expand...
It did come with an extra baffle cut for a 10” speaker, so I’ll be exploring the options. 4 ohm output impedance iirc, so the options are limited.

Got me wondering what that Gorilla sounds like. Link Wray after a 2-day bender?
 
Lol it powered up just fine, I brought it up with a variac and dim-bulb tester, fed a 250 Hz signal into the input. No issues, no hum, very quiet, no hissing or crackling. I took it from the shop to my little music room and plugged 3-4 guitars into it and it sounded great. The Gorilla sounded pretty darn good!
I checked the speaker impedance (actually the resistance) and it is 4 ohm. Considering the limited choices out there for a 4 ohm 8” speaker I can now understand why the gorilla was installed; it was probably the only choice on hand. But it works, the amp is running, and the darn thing starts breaking up at 2-3 with hot humbuckers, even moreso with P90s. Single coils (Texas Specials) sounded very nice.
Okay, so on to the operating table it goes, lots of new components coming, that black grillecloth is annoying the F out of me lol
 

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Just a quick update:
Reworking the entire circuit. New eyelet board, all new everything. I’m following the schematic, no big changes. Someone removed the feedback loop, so I’m going to add a switch so it can be placed in or out (there are 2 holes already drilled in the chassis).
Reworking the cab, re-gluing loose Tolex here and there. Someone went crazy with a staple gun.
Got new grille cloth!
It’s coming together, already played through it, still rockin’ the Gorilla until the new speaker comes in.
 

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Done, it’s pretty much a new amp. Cab, Tolex and hardware original except for the two back panels (MojoTone). They’re very well made and fit perfectly. They leave the drilling to you. Baffle was swapped out for a 10” 5/8” plywood that came with the amp (thankfully!) I applied the new grillcloth (AES). Speaker is a Jensen P10R, after 3 weeks of indecision I went with “tried and true”. The two transformers are original.
The component/eyelet board is new, along with all the electronics, except for one 68k cc resistor, only because I didn’t have another on hand lol. Every other resistor and cap was chosen to be as close in value to the AA764 schematic with one exception; I added a 4th 20uF filter cap to get the amp as quiet as I could (AB764). The 3 pots are original. Tube sockets are original. New power cord.
I tube rolled for hours. All 3 are JAN GE/RCA.
The blackface front panel is/was in poor condition, but I didn’t want to replace it if I could find a way around it. It’s bubbled up and chipped up all over, and every time I touched it, it would leave the white background. So… I carefully touched up literally 100+ spots and then clearcoated the panel in semigloss to stop the chipping. Knobs are new. Any rusty hardware was replaced, it makes a difference! The tube chart was long gone so I grabbed a pic off the web (with a prod date very close to the actual man. date), printed & glued over where the old one was.
You can see the Feedback Loop In/Out on the back. Not exactly easy to get to but you can.

Anyway, I plan to keep it and break that speaker in.
 

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This is the kind of thing that I assume would be cost prohibitive, and therefore, pointless for someone like me to hand over to an amp tech. But, when you have the skills to do it yourself, it's a different story.

Congrats! It looks awesome! :thu:
 
jrockbridge said:
This is the kind of thing that I assume would be cost prohibitive, and therefore, pointless for someone like me to hand over to an amp tech. But, when you have the skills to do it yourself, it's a different story.

Congrats! It looks awesome! :thu:
Click to expand...
It’s not lucrative for sure, if it was, you’d see restos all over the place. I do it for enjoyment and hoping that at least one more amp might make it into the 2040s-50s for someone else to enjoy.
And thanks!
 
Nice, that came out great!

I kind of reminds me of my great grandfather's ax that has been passed down through generations and is now in my garage. In all that time, we've only had to replace the head once, and the handle twice. :wink:
 
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