Rehousing my head into a smaller, metal cabinet. Any words of advice?

[Dave Locher]

I have a late 1970s Randall RG100ES head. I can't figure out how to post a photo, but it is made to look like a full size Marshall head. It's also heavy and big and awkward to move around.
I was planning to build a smaller, lighter wood enclosure for it, but I just googled amp heads and saw several that were all metal. Vox and Bugerra in particular. This appeals to me because my metal working skills are better than my woodworking skills (I customize & rebuild '50s cars as a hobby) and I'm pretty sure I can do it lighter in metal than wood.

It's a solid-state amp so tubes are not a problem but it does have spring reverb. Will that work okay in a metal enclosure as long as I mount the spring unit the same way? It's hanging from the top of the cabinet in a vinyl bag.

I guess I am asking for advice on wood vs. metal for a head enclosure.
Any helpful tips would be appreciated.

 

[Dave Locher]

Re: Rehousing my head into a smaller, metal cabinet. Any words of advice?

No one has any thoughts, opinions, or experiences to share?

 

[crusty philtrum]

Re: Rehousing my head into a smaller, metal cabinet. Any words of advice?

I've rehoused many bits of gear. I usually use wood because it provides better insulation in the event of serious malfunction in high-voltage applications, and also because it looks and smells so much better when it catches fire.

However, your project is s/s and therefore won't have the high-voltage issues.

But you will need to consider cooling .... ventilation for the power transistors ... looking at a pic of the chasis, the heat sink fins are on top, therefore you'd probably want to use some kind of perforated/ expanded mesh or louvered top section. Or i suppose you could consider fan cooling, although that could introduce noise, and problems if the fan burns out.

The starting point will be the chasis mounting points (may be on the base or the sides, I couldn't tell from the pic i found). You'll want a very strong baseplate to ensure any impact on the base won't bend the plate up and cause shorts in the underside of the circuitry and other electrical connections. From there, you can build up your design. (with a metal baseplate, insulate the inside with some thin sheet rubber just in case any flexing ever did cause the base to contact any of the electrical guts).

However, you will need to investigate your earthing system ... I live in Australia where we use 3-pin power outlets and plugs. I believe it may be different in the USA.

To be honest, I doubt there will end up being much difference in weight between the wooden shell and a metal equivalent.

And yes, keep the orientation of the spring the same way as it is in the original configuration, as they are designed to be orientated in specific ways.

You could consider a hybrid arrangement, with a wooden lower section and a perforated/ mesh 'cage' for the upper half, or a simple wooden base/ two sides/ top with mesh for the entire front and back panels for maximum ventilation.

Some of these things are easy at first thought, but there can be a lot involved to get it right, safe and reliable.

 

[crusty philtrum]

Re: Rehousing my head into a smaller, metal cabinet. Any words of advice?

I'm sorry if my post above seems frivolous. Here's a more normal response ...

" Rehousing my head into a smaller, metal cabinet "

Easy. Put a metal bucket over your head.

" Any words of advice ? "

Cut two eyeholes so you can see out.


(phew, I feel better now I've balanced my contribution).

 

[Dave Locher]

Re: Rehousing my head into a smaller, metal cabinet. Any words of advice?

Thank you, Crusty, although I did find the first post more helpful than the second one.
It's funny you said to consider a wood/metal hybrid because that is the way I am leaning after having shopped out materials last night. I'm pretty sure I could come up with something that is light and sturdy.
I had wondered about chassis support. I looked at more images last night and noticed that a lot of the all metalheads use the chassis as the bottom of the cabinet. That just does not seem like a good idea to me. I am definitely going to have some solid support under that sucker.
P.S. I am hoping to avoid finding out what it smells like on fire!

 

[crusty philtrum]

Re: Rehousing my head into a smaller, metal cabinet. Any words of advice?

A metal baseplate could be stiffened with a low-profile piece of channel welded along the length, on the 'outer' side of the panel. Of course that would need rubber feet that were just a little taller than the depth of the reinforcing channel. (i.e. find suitable feet first, then fabricate the channel to be a little less deep than the feet). I've encountered this method in the past, it works well ... the channel is usually moderately wide compared to it's depth. And of course more than one could be used.

 

[Funkfingers]

Re: Rehousing my head into a smaller, metal cabinet. Any words of advice?

Put a metal bucket over your head. Cut two eyeholes so you can see out.

Neil. I think that somebody may have already cornered the market for that idea.

Getting back on-topic, what about rehousing amplifiers in granite?

 

[GoldenVulture]

Re: Rehousing my head into a smaller, metal cabinet. Any words of advice?

Neil. I think that somebody may have already cornered the market for that idea.

Getting back on-topic, what about rehousing amplifiers in concrete

fixed

 

[Demanic]

Re: Rehousing my head into a smaller, metal cabinet. Any words of advice?

Concrete? Granite? I thought the point was to make the head lighter?

Sent from my MotoE2(4G-LTE) using Tapatalk

 

[ginormous]

Re: Rehousing my head into a smaller, metal cabinet. Any words of advice?

Concrete? Granite? I thought the point was to make the head lighter?

Inside joke... speaking of which:

 

[Gearjoneser]

Re: Rehousing my head into a smaller, metal cabinet. Any words of advice?

I rarely have faith in these ideas, until I hear "I customize and rebuild 50's cars as a hobby"or "I'm a furniture designer."

Seriously, anything other than that and I just sigh and move on.

I say don't go generic....make something cool as hell, and then make us drool. I have to admit, I'd rather see a classic chassis rather than a Randall, but do it anyway. Do it right, and you could have a money making venture in your future.

 

[Artie]

Re: Rehousing my head into a smaller, metal cabinet. Any words of advice?

I say don't go generic....make something cool as hell, and then make us drool.

This.

 

[Dave Locher]

Re: Rehousing my head into a smaller, metal cabinet. Any words of advice?

Well, it's gotta be quick & cheap (family, job, etc., etc.) so it won't be TOO cool, but it will be somewhat better than the original, which was bland to the extreme.
BTW, I've already dropped the idea of doing it all in metal because the materials are cheaper to do it mostly in wood AND I'm less likely to damage my car loading it in and out. Wood will be lighter or about the same weight, just not quite as compact.
But if I were to find the right amount of aluminum in a scrap heap somewhere...or if I were to find an old cabinet or appliance of some sort that was close to the right dimensions, then who knows what could happen??

And, of course, it will still be a 1978 Randall head, not a 1959 Fender or whatever. But I like it and it's served me well for 25 years or so.

 

[misterwhizzy]

Re: Rehousing my head into a smaller, metal cabinet. Any words of advice?

There's nothing small about metal.

 

[Dave Locher]

Re: Rehousing my head into a smaller, metal cabinet. Any words of advice?

There's nothing small about metal.

You mean metal music? Agreed. Metal the construction material, however, is quite a bit thinner than wood for the same strength! But I decided trimming less than an inch off the length and width of the enclosure isn't worth the added expense and potential damage to my car. I'd rather toss around a wooden box than a metal one. Although I'm still shopping for some surplus or something that I can repurpose...

 

[misterwhizzy]

Re: Rehousing my head into a smaller, metal cabinet. Any words of advice?

You mean metal music? Agreed. Metal the construction material, however, is quite a bit thinner than wood for the same strength! But I decided trimming less than an inch off the length and width of the enclosure isn't worth the added expense and potential damage to my car. I'd rather toss around a wooden box than a metal one. Although I'm still shopping for some surplus or something that I can repurpose...

Hi, Dave. I make jokes.

 

[Chickenwings]

Re: Rehousing my head into a smaller, metal cabinet. Any words of advice?

You will get 30% more signal strength if you use granite.

 

[Dave Locher]

Re: Rehousing my head into a smaller, metal cabinet. Any words of advice?

Hi, Dave. I make jokes.

I guess with a name like "misterwhizzy" I should have realized.
Best I can figure, if I were to make it all in polished aluminum it would be at least twice as loud as it is now because the molecules in the wood dampen the transmission of sound, right? But what if I do it all in genuine mahogany? Will is sound warmer then??
(I make jokes, too!)

Seriously, though, the cheapest/quickest/most practical option is to make an ordinary wooden box for the top, sides, & bottom but to smaller dimensions and thinner wood than the original. I'll do the front & back a little bit more imaginative. We'll see.
I did find some solid aluminum boat handles at a thrift store that might look nice on the top or sides. It's evolving...

Gearjoneser: Don't worry, I also built my current guitar from scratch. My brother-in-law (who is also my neighbor) builds furniture for a hobby. Whatever I do won't be terribly original or imaginative and it won't be perfect, but it will be competently done!

 

[Dave Locher]

FINALLY finished!

FINALLY finished!

I finally got this project finished. No, I have not been working on it since April. I was out of town for most of May and all of June, plus kids/work/life/etc. You know how it goes. It really didn't take all that long.
If I'd known ahead of time the cost of materials I would have just gone with my original idea to use metal. Aluminum is a little pricey, but so are $10 cab corners and $30 for the textured Duratex coating. (That stuff was worth every penny, though: it made my plywood box look like a real amp. My wife said "Wow, that looks professional!") I reused the Randall feet and handle and I've had that "Custom" emblem in my shop for years, so the only other expense was the $15 half-sheet of plywood and I bought a new pilot indicator light at Radio Shack for 3 or 4 bucks. I could not take the original orange light anymore! This is a nice dark red, and it sits more flush as well.

So here it is!
As promised, it is totally unoriginal. I'm still not sure about the insert shape - I did that to deal with the fact that the head is off center, which I did to balance it out. But it will be super simple to make a new face plate if I ever decide I can't stand it. If I ever really wanted to go nuts it turns out the control plate is just a separate piece of sheet steel that could be replaced very easily. Some spun aluminum and chicken head knobs and this amp would look...absolutely nothing like it sounds. This is a neo-retro as I'm willing to go with it.

It is about 7" shorter, one inch less height and depth, and 15 POUNDS lighter than the original housing. It's amazing how much lighter 1/2" birch plywood (from Lowe's) is compared to the 3/4" thick particle board (or MDF or whatever the heck Randall used) can be. If it weren't for the reverb tank, which I was not willing to eliminate, I could have made it significanlty smaller/lighter.
Now it fits nicely on my 2x12 cabinet, it fits in my car, and I can pretty easily lift it with one hand.

Sorry the photos are so big - I've never tried doing photos on this forum before. I'm also not sure why the fabric looks so pink - it's actually the dark red/burgundy color you see in the "before" photo of the original head.

p.s. The Randall box looks so ratty because some yahoo painted it white, then painted it red, then painted it black before I bought it around '87 or so. So shallow scratches reveal the red paint, deeper scratches reveal the white paint, and really deep scratches go all the way to the original black vinyl. It's been "relic" by me carrying it around to gigs for years.

 

[Artie]

Re: Rehousing my head into a smaller, metal cabinet. Any words of advice?

Wow! Nice job. That really looks sharp. :cool2: