Amp chassis from multiple pieces of sheet metal.

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mcilfilm
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Amp chassis from multiple pieces of sheet metal.

Post by mcilfilm »

My first 5e3 build is coming along nicely.

I built my own sheet aluminum chassis. Drilled it, cut it and bent it. All of the parts fit nice.

Looks just like the real thing.

But it was a pain and since I'm building a custom cabinet anyway, could I have used separate pieces as long as they were connected with ground wires?

Pots on one, tubes and transformers on another?
Or even three panels with Tubes on their own?

I haven't been able to come up with any examples on the web.

Thanks a ton.

Rob.
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M Fowler
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Re: Amp chassis from multiple pieces of sheet metal.

Post by M Fowler »

You could have built in U shape without ends or added wood ends.

Could have bolted all the pieces together. As long as one piece was used for all ground connects you could build it about anyway you wanted. That means the input jack isolated so run ground wire to first bypass cap/resistor, pot grounding to same place as V1a/b ground.

PI grounding with the filter cap for that section.

The rest of the filter caps to it's own ground tab.

Green AC ground to it's own ground tab.

Lot of ways to build amps even without complete chassis.
mcilfilm
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Re: Amp chassis from multiple pieces of sheet metal.

Post by mcilfilm »

Thanks for the reply.
I did build mine in a u shape (Close to the original I guess).

What I was thinking is; could I have wired it up just as shown in lthe ayout only on three sheets of metal instead of the U shape.

(imagine the U shaped chassis built as prescribed but cut where the bends should be and connected with ground wires).

I'm imagining it to be easier from a carpentry standpoint.

Thanks.
tubeswell
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Re: Amp chassis from multiple pieces of sheet metal.

Post by tubeswell »

From the point of view of ground return issues and related hum noise in the signal, I think its less complicated to have one bit of metal. YMMV
He who dies with the most tubes... wins
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Meat&Beer
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Re: Amp chassis from multiple pieces of sheet metal.

Post by Meat&Beer »

Like others have said, sure, no sweat. However, I'm wondering about a couple things.

How do you wire up said amp with it being on separate pieces of metal, and juggle it around getting it in and out of the cabinet or whathaveyou?

You'd probably have to watch what wires and components go where when "bridging the gap" between structures. Especially sensitive stuff in the front, they like (chassis) shielding. Filaments too. Yes you can always fly them... But, again, the maneuvering of the completed unit thing.

If you ever want to mod/update/repair/service this amp anywhere down the road, how much of a pita is that going to be? If the wires from each platform are long enough to say, remove just the face and controls to get at them and other stuffs, that's a good amount of wire slack in there when it's put back.

Assuming, that it's in fact separate plates of metal connected only by wires like what I believe I'm interpreting.

I'd ask, why hasn't this been done before? I've never seen it, anyway.
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M Fowler
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Re: Amp chassis from multiple pieces of sheet metal.

Post by M Fowler »

Ever work on a Peavey Classic 30 they have multiple wires going from main chassis board to top control board so you have to squeeze it together to be able to get all the puts and jacks out of the control panel for removal and repair. I was more worried about removal then figuring out what needed repair on these things, but after doing more it gets easier.

In other words the way you built your chassis is good. :lol:

Mark
tubeswell
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Re: Amp chassis from multiple pieces of sheet metal.

Post by tubeswell »

M Fowler wrote:Ever work on a Peavey Classic 30 they have multiple wires going from main chassis board to top control board so you have to squeeze it together to be able to get all the puts and jacks out of the control panel for removal and repair. I was more worried about removal then figuring out what needed repair on these things, but after doing more it gets easier.

In other words the way you built your chassis is good. :lol:

Mark
Yup. I remember one bad weekend where I took one apart completely and put it back together 13 times trying to find the errant jumper wire. I'll never do that again thanks
He who dies with the most tubes... wins
mcilfilm
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Re: Amp chassis from multiple pieces of sheet metal.

Post by mcilfilm »

Thanks for the replys.
This is a good example of ask first.
It's good to know that it can be done with care. Thanks for that.
However I'm taking M&B's advice to heart.
Can be done but could be trouble.

The U-shaped chassis is already less stable than the ones from the factory, but I did save the ninety bucks extra.

I'm a carpenter and my custom crates are a little different from the originals and thought how easy it would be to just screw down flat pieces of metal like I do on HiFi amps.

Thanks all for your advice.

Heres a couple of pics of the cabinet. I''l post the "head shots" when it's done. A couple of C10q's for a 5e3 on the 4ohm OT lead.
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Kagliostro
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Re: Amp chassis from multiple pieces of sheet metal.

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