Starting an Amp project

FuzzyAce

Rock Star
TGF Recording Artist
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Well, I'm getting the bug again to build something.
Not like I need another project, seeing I have a few guitars that also need some attention. But this should be fun and right up my alley.

This amp began its life as a Vox Valvetronix with a 12" speaker. Decent little amp for what it was, and it used to be my nephew's. Unfortunately (or fortunately lol) it had not been working for years and there was something spilled that got inside the chassis. Anyways, it's mine now so I've decided to gut the whole thing and build a 15-20 tube amp out of it.

Goals:
•15-20 watts, 2x6V6GT power section, 6SL7 PI, and 2x12AX7 in the preamp.
•volume, bass, treble, cut, master, bias switch in the preamp to add more gain, NFB on/off switch. circuit is not based on anything particular (that I'm aware of) due to the gain staging choices and tone controls staggered in the circuit
•use existing chassis, which means drilling out new holes for tube sockets and anything transformer related. This is the trickiest part of the build due to the chassis design and size. It'll take a bit more layout planning which is fine but will be the most time consuming process of the build.
•May or may not laser cut a control plate for the panel. There are existing holes exactly for what I need, but there are extra holes underneath that will not be used. Either way I need to cover these up, I can always use hvac tape. Part of me doesn't mind keeping it bare bones in case I want to change things further down the road.
•Laser cut a Fuzzy's Amp logo (duh) and put in same spot as old Vox logo
•Paint the cab yellow to match my yellow strat. Basically have an amp/guitar pair that fits together aesthetically. Repaint the metal grill black, but put a white vinyl or even grill cloth underneath for contrast. Not sure if I want to see the speaker hole so I'm leaning toward the grill cloth option. Get new black metal corner bumpers and keep existing raised, black handle.
•speaker is tbd. I have options but I'm thinking of using a Tone Tubby Purple Haze I have stashed away. But I also have G12M, EVM12S, V30, Governor, among others.
•cut a new back panel to accommodate for ventilation reasons, reuse and repaint the 2 top panel vent inserts.


The good thing is, I should already have all the parts needed except for white grill cloth. Just going to work on it when I can, no rush. But I figured I'd document it somewhat for those interested. I'm really bad with progress pics, I tend to get caught up in what I'm doing and forget, but I'll try to post as I'm in the process.

Here's what I've done so far:

The stripped down cab ready for primer.
IMG_2104.jpg


Primed grill.
IMG_2107.jpg


Primed cab. I didn't have white primer on hand but this should be fine. I'll likely hit it with white again before doing the yellow.
IMG_2109.jpg

IMG_2108.jpg


Chassis.
IMG_2110.jpg
 
Cool project! I love seeing things like this. Do you have a board lined up for the build or are you going to make your own?

Old Greenlee radio knockout punches are good for making the holes for tube sockets.
 
Cool project! I love seeing things like this. Do you have a board lined up for the build or are you going to make your own?

Old Greenlee radio knockout punches are good for making the holes for tube sockets.
I actually have a punch out set, and also taper bits. (y)
As far as a board goes, I could go in a couple directions. Make my own from some leftover G10 material from an older project -- drill it out and press in the eyelets. Or, use a generic turret board just like this:

p-htbu-2x30_0.png

I already have a bunch of these in various sizes so probably what I'll use. I'm going to do the wiring without a schem or layout too because why not lol. At most a power amp schem for node reference, and tube pinout charts for my sanity. But, of course it wouldn't hurt to draw something out either. I just kind of want to build this one on the fly without too much overthinking is all.
 
Trying to remember to take pics. :grin
Just a little update. Painted some today to further polish the turd.
I decided to go for a two-tone vibe with the creamy front panel contrasting with the squash yellow cab. I'm going to get some small black piping and run it along where the cream and yellow meet. I think it'll tie it all in better. Of course the corner bumps will be black as will the handle and top vents.
I may do a logo like below to put at the bottom left corner of the cream panel. Just lettering laser cut, no border or anything.

Screenshot 2025-05-25 at 6.08.45 PM.png
Screenshot 2025-05-25 at 6.28.58 PM.png
 
After assembling the cab a bit more, putting in a speaker, I've decided to paint that top panel portion yellow as well. It's just not jiving in cream, and takes away from the yellow too much. Still going to do the black piping though. Probably will paint under the metal grill black too. Even if I decide to add grillcloth, having a black base is ideal.
 
Are you having the faceplate custom made?
A friend of mine has a laser cutter which helps!
I draw it out in Illustrator and export a file to be used with it. For the one above, all the hole cutouts will use existing spots on the chassis so less metal drilling I have to do. I just make sure to take accurate measurements for the layout to work.
 
A friend of mine has a laser cutter which helps!
I draw it out in Illustrator and export a file to be used with it. For the one above, all the hole cutouts will use existing spots on the chassis so less metal drilling I have to do. I just make sure to take accurate measurements for the layout to work.
That’s awesome! Can’t wait to see the finished product.
 
That’s awesome! Can’t wait to see the finished product.
Thanks! Not 100% sure when I'll be done with it, I've been slow-walking and just getting to it when I have the free time. But I'll try to post when I actually do something. :grin
 
I had 30 minutes after work, so while I was in the shop I made a quick back panel out of scrap drawer box material.
Still need to rout an area around the chassis so tube heat won't build up. May even do some port holes. Once I do that I'll paint the panel yellow.

Just a little mock up:
IMG_2125.jpeg

IMG_2127.jpeg
 
A few updates. Finally got some more time to finish the back panel and paint. Went ahead and painted the interior of the cab black, put in a different speaker (for now), and added the piping in the front. Still thinking on the circuit, front and back panel layout and logo, could make some small changes but I'm in no huge rush. The chassis is just sitting in there atm, not fully attached or in place.

Screenshot 2025-06-07 at 11.33.30 AM.png
Screenshot 2025-06-07 at 11.33.42 AM.png
 
I had 30 minutes after work, so while I was in the shop I made a quick back panel out of scrap drawer box material.
Still need to rout an area around the chassis so tube heat won't build up. May even do some port holes. Once I do that I'll paint the panel yellow.

Just a little mock up:
View attachment 44855
View attachment 44856
I used to love having access to the shop for my own projects. Clean work, great job!
 
I used to love having access to the shop for my own projects. Clean work, great job!
Thanks! It's hard work polishing a turd. :rofl
It's coming out as nice as I'd hoped considering working with what's there. Would like to begin the chassis layout and drilling soon, but my next few weekends are full so it'll have to wait til after.
Having access to a shop has its pluses, and my next project will be something "nicer" using solid wood. I've been meaning to do a proper head cabinet for my old Legacy amp. Something dovetailed.
 
Racing Yellow?
Nothing that exciting! :LOL:
The color is Summer squash, and that's an accurate description in person. It's just a satin enamel from Home Depot, rust-oleum brand. But it goes on very well and is durable. I also top it off with clear enamel to make it even tougher.
 
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