Crawls Backward (When Alarmed)

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Valco Supro Spectator Amp Completed

I just finished the Supro Spectator over the weekend. I took a lot of pictures, so I may as well post them all, huh?

I've had a Vintage 47 speaker cabinet for 5 or 6 years and never did anything with it. I think it was an early prototype that David Barnes (he is the guy behind the amps) made and sold cheap. It came with a simple sheet metal chassis, but I never got the energy to build an amp on it.

Anyway, I had scouted around on and off for a vintage Valco chassis to go in the cabinet instead. I got this Spectator chassis a year or so ago and found out it was for a smaller cabinet. So I needed to adapt the cabinet a bit.

I didn't want to cut or modify the cabinet, since there is the possibility I'd build another amp on the blank chassis that came with it.

So I decided to make a simple wood block/mounting that could be removed if necessary.

Off to the bandsaw to cut the pieces out of a scrap 2x4 stud.

Bandsaw, you say? Longtime readers will recall my whining desire for a bandsaw. I got a good used one last fall! This is actually the first real 'project' I've done with it.

It's a Rikon Deluxe 14 inch saw, model 10-325. TMD helped carry it down to The Dungeon. Actually, he is sort of like Superman, so he carried it and I watched. What a bargain for me. It's now in the corner where my formerly disgusting but now repainted door is.

Now I have no excuse to start building actual instruments.

I am currently looking at plans and hardwoods. I have some trepidation, but if I goof, I figure I'll just burn the failures in the fireplace.

Here's a test fit of the mounting.

I cut a block with a ledge of sorts at the back where the back lip of the chassis will attach. I'll make a second piece to fill in the gap between this block and the side of the cabinet to the left.

You can see that due to the size of the chassis, it will sit a bit further out than the 'stock' (aka correct) chassis would sit. I'll compensate for that too.

I cut two blocks out of pine and glued them together to make the actual mount.

This was SO easy to cut with the bandsaw. What did I ever do without one? I shudder at the thought.


While the glue was drying, I went to work on the final things to do on the chassis.

First I cleaned it up and then polished it with Griot's Fine Hand Polish.

Came out well, I think.

You have to love those old tube sockets with the tube type printed on them.

I did polish the power transformer end bells, but they still look blah. If I was crazy, I'd take them off and paint them. But I'm not that crazy, it's too much work and it's too cold outside to paint. That's my story and I'm sticking to it.

I was fortunate to get a slight break in the weather, ran outside and painted the end of the block to more-or-less match the color of the chassis.

Here I'm drilling and mounting the wood screws that will hold the block to the side of the cabinet. This way I can just remove the thing if I ever build a different chassis.

I stuck the mount into the cabinet and used the ends of the mounting screws to determine where they will wind up.

Then we drive a pilot hole for each of them, utilizing our high-tech depth gauge. The walls of the cabinet are only about 12mm thick - don't want to inadvertently drill through them.

These cordless drills have changed my life.  And to think I used a corded drill for decades.

The mount installed. You can see the slight difference in depth to the block that's glued to the side of the cabinet.

Aside: I love countersinks.  Love them.

The right side of the chassis will butt up against the side of the cabinet. Since I have that gap there too, I made a spacer (cut to depth exactly on the bandsaw!) for that side.

Screwed that spacer into place.

Cleaned the tube socket pins.

I've been using these stoopid pencil sharpeners for a while now. I don't like them at all!

Need to find another solution. Hmmmm.

I put the chassis in place, and screwed it in.

Then I realized I hadn't done the speaker wiring.

No wonder it didn't make a sound when I turned it on.  DOH!

I also put a cable clip on the inside of the cabinet to hold the AC power cable in place.

Cut another shim/trim panel to fit next to the block.  You can also see 2 of the 4 mounting chassis mounting screws in this shot.  One in front, one on the lip on the wood block,

Not the greatest look, I know. I could have put a piece of sheet metal over it and painted it.

But from 3 feet away, it's not noticeable. This is the back of the amp anyway, so who will see it?

Here it is, finished and with the back panel on. See what I mean about the block? Looks ok from this distance.

Everything cleaned up nicely. It still has scratches and dents, but it's 63 years old, so that's to be expected.

I polished up the switch and the can cap (see it peeking out above). Came out well.

Chicago 51.

That was the postal code for the Valco factory. The current zip code system (Zone Improvement Plan) wasn't implemented until 1963 - 11 years after this amp was built.

Here's the finished amp moved upstairs with some of it's vintage brothers. I really dig the two-tone cabinet.

 
 
 
 

Post a Comment 1 comments:

  • Toy Making Dad said...
    March 1, 2016 at 9:21 AM
    Bandsaws are the potato of the workshop. You can use them for everything. Also, there are those who say Superman is sorta like TMD but with a cape and combed hair.

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