Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: thelonious on December 04, 2013, 07:41:09 pm
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I've just ventured into a bit of woodworking to make an enclosure for a little integrated tube amp I converted to a head. It must have originally been mounted in something, but I'll be darned if I can tell how it was mounted. All I've got to work with are two narrow ears that bend inward on each long edge (see attached pic), and there aren't any nuts pre-attached to the ears like you'd find on a custom chassis. Anyone have a bright idea for how I should mount this thing in my enclosure? So far the only idea I've come up with is to drill holes in the ears and try to JB Weld nuts on, which sounds kinda precarious, even if I didn't get JB weld in the threads...
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Ah, I wonder if I could get really long bolts and run them all the way through the chassis, a la fender combo amp style?
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I wonder if I could get really long bolts and run them all the way through the chassis, a la fender combo amp style?
I've done that very thing with this amp.
with respect, Tubenit
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Wow, Jeff! I've seen that pic several times now and I am always just completely blown away. What a beautiful piece of work. It actually brings a tear to my eye. What a waste. Just thinking what it would sound like with a decent guitar....what a shame..... :icon_biggrin:
Jim :m8
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I've done that very thing with this amp.
Beautiful. I'll give that shot. Mine won't look like that, though!
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+1 on bolts through chassis. If the lip is 3/8" or so and the chassis doesn't weigh a ton, you could also use a sturdy U-Clip fastener on the chassis.
I have had, however, a devil of a time with the precise measuring and drilling to match the cabinet and chassis after everything was built. Measure at least 3 times before you drill. :think1: Regards
dennis
p.s. beautiful cabinet tubenit!
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you don't have much of a lip to work with, but clip nuts might work. if it does, its easier than long thru bolts.
do an image google search for clip nuts.
you'll need to drill holes in that lip. the threaded ones are strongest. there are some that are 'speed nut' type threads that aren't as strong. If you've got transformers hanging off it, use the threaded style.
hardware stores have lots of sizes. make sure you get the right threaded screws to match. I'd look at finish washers and matching philips oval head screws.
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clip nuts might work.
Nice! I forgot those things existed. They might be just the thing in this case since it's a small, lightweight chassis, and it is not going to be hanging upside down (the bolts will really just prevent it from sliding in the enclosure).
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... make an enclosure for a little integrated tube amp I converted ... It must have originally been mounted in something ...
From your description, it obviously had no nuts or bolts attached to the chassis. What if the wood box it previously sat in held it in place?
You're making a head. I presume the chassis will sit on the bottom of the head cabinet. What if the front wall of the cabinet kept the chassis captive on that side, and you add a wood strip to either inside wall of the cabinet to the left and right of the chassis just high enough from the bottom surface of the cabinet to hold the chassis to the cabinet bottom. Now, if you have a back panel, it can hold the chassis into the cabinet.
That would account for all 6 sides of the chassis, and not use any bolts. The front and back panels of the cabinet obviously can have cutouts to give access to the front and back of the chassis, and still hold it in place. If you don't want to completely enclose the cabinet, the back panel only needs to be as-high or a bit higher than the chassis itself (and the strips along the cabinet sides to hold the chassis down).
Originally, I was thinking 2 wood strips that run from back to front along the inside wall of the cabinet, parallel to the cabinet bottom. On further thought, you might already have vertical wood strips to attach the front and back panels. If those vertical strips stop right at the height of the chassis, they could hold it against the bottom, as well as being your mounting points for the panels.
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I would like to see a photo or two of the whole chassis
K
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Wow, Jeff! I've seen that pic several times now and I am always just completely blown away. What a beautiful piece of work. It actually brings a tear to my eye. What a waste. Just thinking what it would sound like with a decent guitar....what a shame..... :icon_biggrin:
Jim :m8
Not to hijack this thread, (and I don't even own any Fender) But you just crack me up with your pokes at Tubenit. :laugh:
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John,
(And any others who may not know) - I have the utmost respect for Jeff. His abilities are simply amazing and he is an important cog that makes this forum work so well. Now, before I start growing lady parts, I have to say that we DO have some fundamental disagreements. Such as:
I like the Allman Brothers, Jeff likes the Jonas Brothers
I like ELP, Jeff likes LMFAO
I like Black Sabbath, Jeff likes the Black Eyed Peas
I like Head East, Jeff likes Kanye West
I like Justin Hayward, Jeff likes Justin Bieber
I like Nicky Hopkins, Jeff likes Nicki Minaj
While I'm in Boston, Jeff is down in Flo Rida and even way out in Hanna Montana
I like Deep Purple, Jeff likes Chris Brown
There are so many examples, but the one thing that will forever divide us is that tele thing...
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I like Black Sabbath, Jeff likes the Black Eyed Peas
I like Head East, I like Nicky Hopkins,
Ah Ha!
First off, Allman Bro's go with out saying. ELP, Jeff's a great writer, oh wait, I thought you were talking about ELO. :laugh:
Second, black eyed peas are a great food! :laugh:
Black Sabbath, I saw live in 75/76 ? at the Chicago Amphitheater, which held at least +20K and the bone head BS fans were so gracious as to rain down on the fans below, M80's, Cherry Bombs, Roman Candles, etc., on those below. All the while Ozzi was flashing the peace sign with both hands. Oh what a show! Hey I'll even give you tickets next time!
Saw Head East, yes once again at the Aragon, opening act out of 4, it was not common and they were really no biggie at all, really weren't ready for the big stage. I still have their album with the wagon full of pot on the front cover, way better than the show I saw.
Nicky Hopkins! That man can play piano!!!!!
Brad :icon_biggrin:
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Jim, ........... What can I say to all that ??? :dontknow:
I know a few of the people or bands mentioned. I think maybe I've heard of the Almond Brothers. :think1:
:icon_biggrin:
With respect, Jeff
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i was also thinking what HotBluePlates said. and if you don't want a back panel you could just use 2 brackets there to keep it in place.
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I would like to see a photo or two of the whole chassis
Ok... but go easy on my rat's nest wiring :icon_biggrin: - there was a lot to fit in a small space.
What if the front wall of the cabinet kept the chassis captive on that side, and you add a wood strip to either inside wall of the cabinet to the left and right of the chassis just high enough from the bottom surface of the cabinet to hold the chassis to the cabinet bottom. Now, if you have a back panel, it can hold the chassis into the cabinet. That would account for all 6 sides of the chassis, and not use any bolts....
That is a great idea. I would have loved to use no bolts since I'll probably be removing the chassis for mods every once in a while. I looked for creative ways to make it happen, but the chassis is so small that there is virtually no clearance between the knobs and the edges of the chassis, and there's only a little clearance between the PT and the side of the enclosure - wood strips that were thin enough to fit through would have been fragile.
I made a trip to ACE Hardware and looked at all their fasteners. They called their threaded speed nuts "extruded U nuts" or something like that. Unfortunately, the smallest ones they had were for 1/4" bolts. Even their clip-on (J) speed nuts were just a little too large to clip on the amp's little 3/8" lip. They had flat speed nuts for #4 and #6 bolts, but then I would be using JB Weld again...
In the end, I decided to bolt through the entire chassis, and that worked fine even if it's a bit uglier. But then, this build isn't exactly going to win a beauty pageant anyway. :laugh: I think it will look okay once I sand/stain/poly the wood and figure out how to finish the front and back. On a side note---hickory might look really nice, but holy moly did it destroy my router bit quickly!
(http://i.imgur.com/Hvd3zWD.jpg)
(http://i.imgur.com/aGhIYVY.jpg)
(http://i.imgur.com/W6z86cu.jpg)
(http://i.imgur.com/UfqkpRv.jpg)
(http://i.imgur.com/caN8Xhn.jpg)
(http://i.imgur.com/zjr8gKH.jpg)
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I would use four sheet metal screws through the bottom and screwed into the lip on the chassis.
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I would use four sheet metal screws through the bottom and screwed into the lip on the chassis.
I wondered if vibration would be an issue with that over time, but come to think of it, a drop of loctite or nail polish likely would have taken care of that.
I've done that very thing with this amp.
Jeff, what did you use as a clear coat? It's gorgeous.
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Nice work, If it works and sounds great, then its a work of art not "a rats nest".
I see that the option of timber strips down the vertical sides would require very thin strips. I am able to get aluminium angle 20mmx 12mm(3/4 x 1/2") that would fit to the vertical sides with the 20mm side fixed between the chassis and the side panel. This would give you something to hold a front panel in place as well.
I'm also with Sluskey, with the screws through the cab and into the lip of the chassis and when the chassis sit in the bottom of the cab the screws will hold into the metal without any problem. I done the same when the chassis hangs upside down and no problems.
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Nice work, If it works and sounds great, then its a work of art not "a rats nest".
Thanks Timbo! It sounds great, so I'm going to call it a win.
I'm also with Sluskey, with the screws through the cab and into the lip of the chassis and when the chassis sit in the bottom of the cab the screws will hold into the metal without any problem. I done the same when the chassis hangs upside down and no problems.
Good to know. I will definitely try that next time if I have a similar situation; it sounds like the easiest solution when there's not much room.
Cheers to everyone for your help!!
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I see that the option of timber strips down the vertical sides would require very thin strips.
That's actually ideal.
If you compared 2 strips, one 1"x1" and the other 2" x 1/2", the 2 x 1/2 would hold stronger if the wide 2" surface is what gets glued to the cabinet sidewall.
If the strip is long in the horizontal direction, it becomes a lever that the chassis pushes against, and tries to rip itself from the cabinet side. The other method (long surface against wall, short surface touching chassis) actually tends to push the strip tighter against the cabinet sidewall. It also tends to transfer the weight of the chassis to the larger wall instead of putting it all on the glue joint.
Glad I got something I can use from the civil engineering part of a freshman intro engineering class...
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3/8" is 9.5250mm
this, in M3 or M4 version will fit on the lip of the chassis
then 4 screws crossing the bottom of the case
http://www.bullonerieromagna.com/articolo-categoria.asp?articolo=540&cat=557&lng=IT (http://www.bullonerieromagna.com/articolo-categoria.asp?articolo=540&cat=557&lng=IT)
(http://www.bullonerieromagna.com/public/940.jpg)
K