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I'm going to create a thread for this amp since it is my intention at the end of the build to publish the schematic and any relevant details so that anyone who's crazy enough can build this amp. So for now this (and the amp) are a work in progress and just somewhere where I can share pictures. Actual information will come later. :)

Night #0 of PS chassis fabrication: I did a preliminary layout of all of the parts on a large 17" x 14" x 4" Hammond Steel chassis that I happened to have laying around. It seemed big enough so I took rough measurements of where everything was located so that I could tweak them later for better alignment and symmetry. I'm not all that concerned about everything being dead-nuts accurate for this amp build. The look is going to be decidedly industrial, frills need not apply.

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Night #1 of chassis fabrication for the power supply: I got all of the hole centers marked and drilled a majority of the small diameter mounting holes. Both the transformer and the chokes are mounted on vibration isolating grommets, not strictly necessary but they can't hurt. Came home early the next day from work to break out the 2" hole saw to cut holes for the large motor-run caps and drill the associated mounting holes.

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Night #2 of PS fab: not much time tonight, drilled a few of the larger holes for wire penetrations in the chassis and installed insulating grommets to prevent wire wear and shorts. Also test fit the caps and small chokes. I erroneously bought a 2-1/16" hole saw so the cap holes are slightly oversized, oh well, there are worse things. I'll pick up the proper saw for the remaining 2, 2" diameter caps in the amp section.

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Night #3 of PS fab: drilled the remainder of the wire routing holes in the chassis so that I could do a fairly complete mock-up of the iron and caps. All seems to fit well but holy hell this thing is heavy.

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Tomorrow I'll pick up the remaining bits and parts that I need to complete the PS fab, all that I really need is a 1-1/8" bit for the tub sockets. I could use a stepped bit that I have but even with the drill press that bit gets unwieldy and I'd rather not trash the chassis at this stage.

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In addition to a regulator for the PS, a CCS plate load for the first stage will decrease distortion, a CCS cathode load for the second stage will also decrease distortion, and using a MOSFET instead

Hey hey, come on now, the main constraint of this exercise was OTL  give the man what he wants, even if it is worse.

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a large 17" x 14" x 4" Hammond Steel chassis that I happened to have laying around

You need to adopt me so I can just wander around seeing what's just "laying around" to use for builds... Between wandering around at your place and KGs...

Looks good so far!

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Thanks guys, so far so good.

looks great! so, what's the trick to using a hole saw? Those holes look very nice, considering...

No real trick other than using a drill press, drilling the appropriate pilot hole, using the right speed and holding the material tightly in place. I've got a bench-top drill press that makes things pretty easy and I built an over-sized table for it so that it fully supports even stuff as large as this chassis. I'll try and remember to post a picture of it.

You need to adopt me so I can just wander around seeing what's just "laying around" to use for builds... Between wandering around at your place and KGs...

Looks good so far!

Heh, I'm quite sure that my workshop and KG's are world's apart when it comes to goodies laying around. I had originally bought this chassis for my Aikido project but have since sold those parts and the buyer didn't want the chassis. It worked out quite well really and the amp will be going in a matching 17 x 12 x 3 chassis. Neither really needs to be that big but I'd rather have room to spare when it comes to routing wires and the inevitable probing during troubling shooting. Cramped space + high voltage = not good for Nate's health.
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looks great! so, what's the trick to using a hole saw? Those holes look very nice, considering...

Do you have difficulties? I can give you a few pointers. I like to clamp the metal to a wooden sacrificial substrate, use a small drill bit to make a starter hole, and use only sharp hole saws. It also helps to use a drill press, but if one isn't available I use a big 1/2" drill with a handle. This one actually...

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The amp is looking great Nate!

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Really nice, Nate. I'm looking foreword to following this tread then seeing and hearing it at CanJam.

btw, I just got home from work and the cables were waiting for me. They look great. I'm going to check them out tomorrow. I'm zonked and going to sleep now.

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Looks like it needs industrial casters fitted for mobility :laugh:

I'm already realizing that I'm going to have to do something to stiffen the chassis, it's no match for the weight of the iron. I probably won't get to that before FLA but it'll have to happen at some point. The big trafo on the left side weighs about 15lbs and it's model number is "BFT", no joke. And that's the lighter of the two big pieces of iron, the large primary choke on the right weighs 21lbs.

:kitty:

It's going to be fun watching the progress of this beastie.

It should go relatively quickly at this point or at least it had better if I have hopes of bringing it to CanJam. The power supply is "scheduled" to be done this weekend and then I'll be stuck waiting for the amp chassis to arrive on Wednesday of next week. :fingerscrossed:
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Nate what headphones are you planning on driving with this monster?

Everything. >:D

At least that was the idea that was used for design. I'll post a brief history of how this project came together some time this weekend if I have time.

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Heh, I'm quite sure that my workshop and KG's are world's apart when it comes to goodies laying around.

Of this you can be sure. I'm now a permanent member of the instrument modeling shop

in addition to everything else, and well the NC toys and bridgeports... There is no limit.

Even at home i have a mill and a lathe, a precision (.0001) drill press and a 1 foot shear.

But really drilling holes that way is all sorts of very dangerous. Those hole saws are for wood.

NOT FOR METAL. Go and get a couple sizes of chassis punches. Not very expensive. Definitely

not expensive compared to 30+ stitches to your stomach when the chassis lets loose.

You can find the chassis punches (greenlee's) all over the place, and at hamfests for $5 each.

I have a dozen different sizes at home, most are older than I am, and will last forever if

you don't do something really stupid with them.

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But really drilling holes that way is all sorts of very dangerous. Those hole saws are for wood.

NOT FOR METAL.

Actually, the ones that I'm using are bi-metal hole saws, specifically made for working with metal. I may be a hack but I do believe in safety first and always use the right tool for the job. Maybe not the best tool, but the right tool nonetheless. And while I'd certainly prefer to be using something like a greenlee punch for this type of work the three that I would need for this project (2-1/2", 2" and 1-3/8") would cost around $320 which makes them decidedly cost prohibitive. It'd be cheaper to have the panel made by FPE, which I may very well do if I decide to do a final version of the amp.
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