Advice needed...

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The4thWatcher13
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Re: Advice needed...

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TriodeLuvr wrote:
Mon 04/12/21 12:35 pm
I've been looking over the photos you posted, thinking about the additional tube socket. Even with a fair amount of metal working tools and options for bending and cutting sheet metal, it isn't evident to me how you'll add another tube and create an amp that can be bolted into a case. I think you'll eventually need to remove the output transformer and mount everything on a new chassis.

Just to present one option, Lloyd Pans sells square-sided aluminum cake pans that are 14 gauge (.063") aluminum with welded corners. This is heavier gauge than the thin stuff sold by Hammond and probably about the limit for working with hand tools. A 6" square pan in 2" or 3" depth is about $20. They have rectangular pans too, but they're probably much larger than what you need for an amp like this. Anyway, one of these pans would be an inexpensive option if you have tools like chassis punches and a step drill.
https://lloydpans.com/bakeware/cake-pan ... -pans.html
I've shortened and twisted the heater wires and there's a definite improvement. I also moved said wires around a bit which had an audible effect on the hum. I think case solved. So I'm taking your comments about re-mounting this nightmare into a suitable chassis quite seriously. As you can see it's kind of a cluster in there and I"m not sure adequate separation is going to be possible considering current chassis size. I'm sure I can lay this out better from scratch.
So my first move is always to storage where I may have a suitable candidate. If nothing's there then I'll "pan it"!
It's something I had actually thought about but hoped I wouldn't need to do. But if you're going to do something, do it right. And this point in the project is pretty much the right time too do it.
Thanks for the recommendation and link.
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Re: Advice needed...

Post by JMPGuitars »

It's true the Hammond enclosures are only .04" thickness, but that's fine for such a small project. Use metal fender washers to mount your transformers for reinforcement. I'd prefer a welded chassis with a securely fitting lid over a cake pan for the same price.

https://www.hammfg.com/electronics/smal ... assis/1444

The 1444-862 is $14.62 without the lid, or about $22 with the lid. That's definitely worth it. The shielding the attached cover plate will give you is worth it alone.

Thanks,
Josh
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Re: Advice needed...

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JMPGuitars wrote:
Mon 04/12/21 8:15 pm
It's true the Hammond enclosures are only .04" thickness, but that's fine for such a small project. Use metal fender washers to mount your transformers for reinforcement. I'd prefer a welded chassis with a securely fitting lid over a cake pan for the same price.
https://www.hammfg.com/electronics/smal ... assis/1444
The 1444-862 is $14.62 without the lid, or about $22 with the lid. That's definitely worth it. The shielding the attached cover plate will give you is worth it alone. Thanks, Josh
Thanks Josh, it's great to have options for this kind of thing. I found no suitable candidates in storage though I did find some parts that will be used. There's only one concern I have about the Hammond chassis';..that is that they don't have Silver-Kote™ and Dura-Kote™! What will I do if I over cook my amp? I'll have a hell of a time getting it out of the cabinet! :lol:
But seriously, I appreciate both suggestions. I'd love to see some photos of amps that have been built out of either. I'll look around the site to see if there are any here.
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Re: Advice needed...

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The4thWatcher13 wrote:
Mon 04/12/21 8:56 pm
Thanks Josh, it's great to have options for this kind of thing. I found no suitable candidates in storage though I did find some parts that will be used. There's only one concern I have about the Hammond chassis';..that is that they don't have Silver-Kote™ and Dura-Kote™! What will I do if I over cook my amp? I'll have a hell of a time getting it out of the cabinet! :lol:
But seriously, I appreciate both suggestions. I'd love to see some photos of amps that have been built out of either. I'll look around the site to see if there are any here.
Ack, I didn't consider that, you might want to set an oven timer.

There's been thousands of amps and projects built with those Hammond chassis. There are also places that sell blank amp chassis in the $30 to $60 range, at .09" thick.
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Re: Advice needed...

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JMPGuitars wrote:
Mon 04/12/21 8:15 pm
I'd prefer a welded chassis with a securely fitting lid over a cake pan for the same price.
Try one before you knock it. The corners of the Lloyd boxes are fully welded. The Hammonds are spot welded crap. I've used both, and the Lloyd product is far superior.

Jack

EDIT: And they do sell lids.
Last edited by TriodeLuvr on Tue 04/13/21 12:24 pm, edited 1 time in total.
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Re: Advice needed...

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The4thWatcher13 wrote:
Mon 04/12/21 8:56 pm
I'd love to see some photos of amps that have been built out of either.
8 X 16 Lloyd box:

Image
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Re: Advice needed...

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JMPGuitars wrote:
Tue 04/13/21 5:51 am
The4thWatcher13 wrote:
Mon 04/12/21 8:56 pm
..I appreciate both suggestions. I'd love to see some photos of amps that have been built out of either. I'll look around the site to see if there are any here.
Ack, I didn't consider that, you might want to set an oven timer. There's been thousands of amps and projects built with those Hammond chassis. There are also places that sell blank amp chassis in the $30 to $60 range, at .09" thick.
For some reason I was having a hard time imagining what this would look like so I hit the interweb and now remember these chassis'. I've been thinking "in cabinet" style for so long I'd never really considered it as a separate head. Doh!
Thanks!
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Re: Advice needed...

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TriodeLuvr wrote:
Tue 04/13/21 12:16 pm
Try one before you knock it. The corners of the Lloyd boxes are fully welded. The Hammonds are spot welded crap. I've used both, and the Lloyd product is far superior.

Jack

EDIT: And they do sell lids.
Lids too? That's cool. I only use professionally made chassis for my amps, I couldn't sell an amp made on a cake pan. Of course, I don't use the Hammond stuff for amps either. I only use Hammond for accessory things like attenuators, and test equipment, or pedals.
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Re: Advice needed...

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TriodeLuvr wrote:
Tue 04/13/21 12:20 pm
8 X 16 Lloyd box:
Damn, that's sweet! I'll be ordering up something today for sure.
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Re: Advice needed...

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Hmmm... On the other hand, you could call your brand "Cake Amps" and make it your thing. Easy slogan: "These amps are sweet!"
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Re: Advice needed...

Post by TriodeLuvr »

LOL, please don't bake your amp! A few things to mention...

The Lloyd boxes have flanges bent outward on all four sides. The front and rear flanges had to be removed to fit my combo case. Before ordering, think about whether you'll need to do the same and how you'll do it. I used a router with a speed controller and a straight-sided carbide trimming bit. Also, because the front and rear panels contact the corners, I filed the welds flush with a hand file. I also added angle aluminum to strengthen the side flanges and hold the cage nuts. That won't be necessary with a lighter amplifier like yours.

Lloyd might be able to make a box with the flanges bent inward, and might also be able to weld on the inside. I already had the box I used, purchased it a number of years ago, but this is worth asking about.

You should also consider how you'll label the amplifier. I wanted to use a thicker chassis for my amp, something .090" or so like Josh mentioned. However, I also wanted to use my own .125" front and rear aluminum panels so I could engrave the lettering myself and make custom cutouts. I can't do this on the chassis directly (too big for my mill), and the combined thickness of .125" plus .090" is too much for pots and switches. So, I used the .063" from Lloyd. The separate panels allowed me to mill the faces the way I wanted, and the panels helped stiffen the chassis (again, not necessary in your case).

Chassis punches and step bits work really well with .063 aluminum. A hand nibbler, not so much. Even though it's supposed to work with this thickness, mine constantly jammed and was very slow and difficult to use. This is one area in which a .040 or .050 box like Hammond would be easier to work with.

Jack
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Re: Advice needed...

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TriodeLuvr wrote:
Tue 04/13/21 2:46 pm
You should also consider how you'll label the amplifier. I wanted to use a thicker chassis for my amp, something .090" or so like Josh mentioned. However, I also wanted to use my own .125" front and rear aluminum panels so I could engrave the lettering myself and make custom cutouts. I can't do this on the chassis directly (too big for my mill), and the combined thickness of .125" plus .090" is too much for pots and switches. So, I used the .063" from Lloyd. The separate panels allowed me to mill the faces the way I wanted, and the panels helped stiffen the chassis (again, not necessary in your case).

Chassis punches and step bits work really well with .063 aluminum. A hand nibbler, not so much. Even though it's supposed to work with this thickness, mine constantly jammed and was very slow and difficult to use. This is one area in which a .040 or .050 box like Hammond would be easier to work with.

Jack
In your case, I would consider cutting the potentiometer holes in the front panel wider than the nut. It would give a cool 3D look, and make standard pots work as long as there's enough space for the knob to catch...if not, you can make the holes wider than the knobs too. That might look pretty cool.

You're right that the hand nibbler has no problem at all with the Hammond stuff. I didn't have much trouble on .06" aluminum on the GDS chassis either though.

Thanks,
Josh
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The4thWatcher13
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Re: Advice needed...

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All great info, gentlemen, thank you very much! Just getting back to this today, so just a little more research and a trigger to pull.
M
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Re: Advice needed...

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OK, I decided to go with the Hammond chassis and bottom cover. If it don't work I'll start "baking"! :wink: I've been wondering about chassis punches tho. I've never used one and I'm wondering if one will be necessary for this project. I've got to do the 4 tube holes, holes for the transformers, pots jacks and so forth. The largest of which, 1", will be for the multi-cap I believe. (..and I ordered 47uF/160V axial caps as a replacement option) Do you guys think I'll need a chassis punch this time around? Step bits are pretty available locally unless I'm in need of a particular type. I'd think a punch would probably yield a much nicer hole but there are a lot of punch options out there and I got no idea.
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Re: Advice needed...

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The4thWatcher13 wrote:
Tue 04/13/21 4:53 pm
OK, I decided to go with the Hammond chassis and bottom cover. If it don't work I'll start "baking"! :wink: I've been wondering about chassis punches tho. I've never used one and I'm wondering if one will be necessary for this project. I've got to do the 4 tube holes, holes for the transformers, pots jacks and so forth. The largest of which, 1", will be for the multi-cap I believe. (..and I ordered 47uF/160V axial caps as a replacement option) Do you guys think I'll need a chassis punch this time around? Step bits are pretty available locally unless I'm in need of a particular type. I'd think a punch would probably yield a much nicer hole but there are a lot of punch options out there and I got no idea.
Use step bits. Punches are expensive, and only worth it if you're going to be using them a lot. I make enough stuff that I have a few, but I generally prefer to let other people make chassis for me when I can. Maybe one day I'll buy one of them cute lasers I've been eyeing. lol
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Re: Advice needed...

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JMPGuitars wrote:
Tue 04/13/21 2:52 pm

In your case, I would consider cutting the potentiometer holes in the front panel wider than the nut. It would give a cool 3D look, and make standard pots work as long as there's enough space for the knob to catch...if not, you can make the holes wider than the knobs too. That might look pretty cool.

Thanks,
Josh
Josh, I counterbored all the potentiometer holes in the front, just so the nuts would catch enough threads. You can't see the work, because it's all covered by the knobs. I do like the idea of counterboring around the knobs, but that's much more work than it might appear (especially with so many controls). Each bore would require the additional steps of applying a small roundover or bevel around the edge, then the concave face of the bore has to be finished to remove milling marks. Not sure how I would even accomplish the latter without a bead blaster. In another life, I would have a $200,000 laser CNC to quickly resolve problems like this. :lol:

Jack
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Re: Advice needed...

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The4thWatcher13 wrote:
Tue 04/13/21 4:53 pm
I've been wondering about chassis punches tho. I've never used one and I'm wondering if one will be necessary for this project. I've got to do the 4 tube holes, holes for the transformers, pots jacks and so forth. The largest of which, 1", will be for the multi-cap I believe.
If you buy good quality step bits, they'll make extremely good precision holes. I'm using a U.S.-made Milwaukee from Lowe's that goes from 1/8" to 1/2" in 1/32" increments. Note that I'm referring here to step bits used with a drill press. I suspect the quality of the cut suffers if a hand dill is used. For larger holes, the step bits get kinda pricey. I use punches if it's an area that I can't reach with the mill. Punched holes aren't quite as perfect as the step bits, because the edges of the holes aren't entirely uniform all the way around. They're more than good enough for things like tube sockets and capacitors though, especially considering the whole thing will end up hidden inside a cabinet. One other option is to buy the few punches you need on eBay, then resell them when you're done. If you do decide to buy punches, be sure to buy the "radio chassis" punches, not knockout punches or other types. Many punches are sized by the diameter for a piece of pipe or conduit, and it's not actually the diameter of the hole they cut.

Jack
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Re: Advice needed...

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TriodeLuvr wrote:
Tue 04/13/21 6:28 pm
If you do decide to buy punches, be sure to buy the "radio chassis" punches, not knockout punches or other types. Many punches are sized by the diameter for a piece of pipe or conduit, and it's not actually the diameter of the hole they cut.

Jack
I have a list of the correct punch part numbers (and other useful stuff) here: viewtopic.php?f=25&t=25173

Thanks,
Josh

PS. I also dream about 6 figure lasers. lol
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Re: Advice needed...

Post by The4thWatcher13 »

JMPGuitars wrote:
Tue 04/13/21 9:29 pm
TriodeLuvr wrote:
Tue 04/13/21 6:28 pm
If you do decide to buy punches, be sure to buy the "radio chassis" punches, not knockout punches or other types. Many punches are sized by the diameter for a piece of pipe or conduit, and it's not actually the diameter of the hole they cut. Jack
I have a list of the correct punch part numbers (and other useful stuff) here: viewtopic.php?f=25&t=25173
Thanks, Josh ..PS. I also dream about 6 figure lasers. lol
Thanks Josh, that's great info!
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Re: Advice needed...

Post by The4thWatcher13 »

TriodeLuvr wrote:
Tue 04/13/21 6:28 pm
The4thWatcher13 wrote:
Tue 04/13/21 4:53 pm
I've been wondering about chassis punches tho. I've never used one and I'm wondering if one will be necessary for this project. I've got to do the 4 tube holes, holes for the transformers, pots jacks and so forth. The largest of which, 1", will be for the multi-cap I believe.
If you buy good quality step bits, they'll make extremely good precision holes. I'm using a U.S.-made Milwaukee from Lowe's that goes from 1/8" to 1/2" in 1/32" increments. Note that I'm referring here to step bits used with a drill press. I suspect the quality of the cut suffers if a hand dill is used. For larger holes, the step bits get kinda pricey. I use punches if it's an area that I can't reach with the mill. Punched holes aren't quite as perfect as the step bits, because the edges of the holes aren't entirely uniform all the way around. They're more than good enough for things like tube sockets and capacitors though, especially considering the whole thing will end up hidden inside a cabinet. One other option is to buy the few punches you need on eBay, then resell them when you're done. If you do decide to buy punches, be sure to buy the "radio chassis" punches, not knockout punches or other types. Many punches are sized by the diameter for a piece of pipe or conduit, and it's not actually the diameter of the hole they cut. Jack
Thanks Jack, I'll be heading out today to get a quality step drill set. I'll hold off on the punch system for the moment. I guess I'm in a little bit of a holding pattern until the chassis get's here. Mouser didn't have any in stock so went to Digikey. In the mean time I'll be reading and going over the things we've discussed previously. I'm really enjoying being in this group. You guys are great and I appreciate your sharing your knowledge and experience.
M
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