Hello All,
After years of messing around I've finally decided to go ahead with my Red Light District build. There's nothing really new here, but I thought it'd be nice to chronicle things as they progress. And who knows, maybe I'll just learn something and even make a few friends along the way! 🙂
Moderators: The original thread is a lot to swallow at once - and yes, I've read it thoroughly (more than once!). I struggled with whether or not to post there; I ultimately decided to start a new thread. You won't hurt my feelings if you disagree, or if you think it more appropriate to place this thread elsewhere.
The first picture shows the first step in milling the wood for the chassis. I found some nicely figured Bubinga cutoffs at my local wood store that seemed perfect for the job. The hardest parts of the whole deal were cutting the rectangular hole for the IEC connector, and milling the square sockets for the el-cheap-o meters I plan to flush-mount later. Believe it or not, the miters were the least worrisome to accomplish!
After years of messing around I've finally decided to go ahead with my Red Light District build. There's nothing really new here, but I thought it'd be nice to chronicle things as they progress. And who knows, maybe I'll just learn something and even make a few friends along the way! 🙂
Moderators: The original thread is a lot to swallow at once - and yes, I've read it thoroughly (more than once!). I struggled with whether or not to post there; I ultimately decided to start a new thread. You won't hurt my feelings if you disagree, or if you think it more appropriate to place this thread elsewhere.
The first picture shows the first step in milling the wood for the chassis. I found some nicely figured Bubinga cutoffs at my local wood store that seemed perfect for the job. The hardest parts of the whole deal were cutting the rectangular hole for the IEC connector, and milling the square sockets for the el-cheap-o meters I plan to flush-mount later. Believe it or not, the miters were the least worrisome to accomplish!
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Of course, that effort is all for naught if it's not properly glued! The eagle-eyed among you might note that there aren't any triangular gussets glued in at this point. I'm waiting until I have more of the electronic layout configured before installing those (don't ask me how I know!).
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While the glue on the wooden portion of the chassis dried, it was time to work on the top plates. These are 1/8" thick 6061-T6 aluminum, which is easy to machine and drill. Really nice stuff to work with!
The left plate is for the amplifier section; the right is for the not-so-separate power supply (do a search for Poinz's Musical Machine; I shamelessly stole the idea from him). The blue stuff on the power supply plate is the layout fluid left over from, well, laying out all of those stinkin' holes. The smaller ones around the perimeter are all counterbored to accept the heads of a boatload of 4-40 socket head cap screws that'll ultimately attach the plates to the chassis.
The left plate is for the amplifier section; the right is for the not-so-separate power supply (do a search for Poinz's Musical Machine; I shamelessly stole the idea from him). The blue stuff on the power supply plate is the layout fluid left over from, well, laying out all of those stinkin' holes. The smaller ones around the perimeter are all counterbored to accept the heads of a boatload of 4-40 socket head cap screws that'll ultimately attach the plates to the chassis.
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Trial fit of all the parts made to this point, with apologies for the picture quality. The power supply transformers are fastened with 18-8 stainless 10-32 socket head cap screws; the two James output transformers ship with their own hardware (undoubtedly metric).
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Once I was satisfied with the general chassis layout I focused on arranging and mounting the tubes. I had six nice ceramic chassis-mount noval sockets (incidentally, I bought them from Stan of ESRC at a hamfest years ago), and I really wanted to mount them in a way that was at least somewhat out of the ordinary. After staring at them for a while I decided that I really, really didn't like the included mounting rings; they looked cheap when mounted on top, and the holes in the mounting lugs were too close to the edge of the ceramic to allow for mounting under the plate using the hardware on hand. So... I decided to make my own.
The first three pictures show how I began laying out the general pattern using my usual weapons of mass destruction: a scratch awl, compass with a scribing tip, layout fluid and a spring-loaded center punch. Looks easy, eh? It's actually not that bad. The hard part was dividing an arc into three segments, which I had to do for the four larger sized rings.
For material I used a piece of 3/16" aluminum plate left over from a VTV linestage project I'd built some 10 years ago. I have no idea what that particular alloy was, but bad memories resurfaced the second I started machining.
It had a "feel" I can only describe as "gummy" - it produced a chip that balled up and stuck to every cutting tool I used, regardless of how much oil I slathered on. My machinery literally looked like I'd slung a bunch of cold solder balls all over it. Note to self: be certain of the alloy you're using, and shy away from b****rd material, if possible!
After three hours of drilling, sweating, filing, cursing, deburring, and buffing I was rewarded with the six rings shown in the last picture. I suppose I could have saved myself a load o' trouble by just ordering the d**ned things from some overseas outfit - but this is DIY after all... Yeah. 🙄
The first three pictures show how I began laying out the general pattern using my usual weapons of mass destruction: a scratch awl, compass with a scribing tip, layout fluid and a spring-loaded center punch. Looks easy, eh? It's actually not that bad. The hard part was dividing an arc into three segments, which I had to do for the four larger sized rings.
For material I used a piece of 3/16" aluminum plate left over from a VTV linestage project I'd built some 10 years ago. I have no idea what that particular alloy was, but bad memories resurfaced the second I started machining.
It had a "feel" I can only describe as "gummy" - it produced a chip that balled up and stuck to every cutting tool I used, regardless of how much oil I slathered on. My machinery literally looked like I'd slung a bunch of cold solder balls all over it. Note to self: be certain of the alloy you're using, and shy away from b****rd material, if possible!
After three hours of drilling, sweating, filing, cursing, deburring, and buffing I was rewarded with the six rings shown in the last picture. I suppose I could have saved myself a load o' trouble by just ordering the d**ned things from some overseas outfit - but this is DIY after all... Yeah. 🙄
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As SY mentioned in his original article, there's that pants-saturating moment of truth that very first time the power supply is, um, "fired up", if you'll pardon the phrase. So to prepare for the event I thought it'd be a good idea to adopt a wide stance. Well, for the amplifier at least.
One of the nice things about DIY is the sheer amount of "stuff" one accumulates over the years from unstarted projects, ones that were abandoned, or those that were stomped on out of sheer frustration. I was going to actually turn a set of pedestals on my lathe just for this build, but then I unearthed a nice set of slotted columns I'd made for an old Williamson project that didn't quite make it off the breadboard. Here, I'm slicing one of them on the bandsaw. Yes, I know there's a lot of blade exposed... 😱
One of the nice things about DIY is the sheer amount of "stuff" one accumulates over the years from unstarted projects, ones that were abandoned, or those that were stomped on out of sheer frustration. I was going to actually turn a set of pedestals on my lathe just for this build, but then I unearthed a nice set of slotted columns I'd made for an old Williamson project that didn't quite make it off the breadboard. Here, I'm slicing one of them on the bandsaw. Yes, I know there's a lot of blade exposed... 😱
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While the glue dried on the pedestals, work resumed on the amplifier section top plate. Over the past several days I'd been reviewing my Morgan Jones books while experimenting with a variety of tube arrangements. Whatever the design, it had to meet these criteria:
I took the right picture after an unbridled urge for instant gratification. It's finally starting to come together! Time for a break...
- The power tubes had to be at a sane distance from the OPTs - and each other - to minimize radiant heating effects and maximize convective cooling (the oversized socket clamps were designed in part to force this issue).
- The arrangement had to be aesthetically pleasing (WAF, you know).
- The above had to be accomplished without sacrificing mechanical or electronic integrity (hey, I'm an engineer).
- It had to allow the LED arrays to spew forth their offering in a visually striking, but not-too-tacky manner.
I took the right picture after an unbridled urge for instant gratification. It's finally starting to come together! Time for a break...
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I love the military/aircraft fastener look but, wheeeew, that's a lot of work (screwing)! Great job, for sure!
Thanks for the kind words, 20. Yeah, that is a lot of drillin'; I've started thinking of this beast as the "holey terror". 😀
All said, the hard part isn't the drilling, but the layout - and even that's more tedium than anything. It just takes patience, magnification (at my age), and a willingness to step back and think as the situation requires. Drilling's a cinch, as the bit will (within reason) tend to seek the center punch hole. Just shift into Zen mode, position the metal and be one with the machine...
As for the effect, well... sometimes things morph into something other than what one plans. In this case I was inspired by a 1950's themed coffeehouse in Albuquerque; lots of '50's-style "googie" retro stuff with a "spaceship" look. Who knows, maybe it'll still work out...
BTW, I noticed you're in Winston-Salem. I lived in the Triad area for nearly 20 years before my work took me out west. I still have lots of friends and family there, and I really miss them - and all the hamfests and CC-AWA swap meets I used to attend.
And that "gummy" metal I described came from D.H Griffin in Greensboro - where I also once purchased 10 old Tektronix 'scopes for $1 per pound! Ah, the good old days...
All said, the hard part isn't the drilling, but the layout - and even that's more tedium than anything. It just takes patience, magnification (at my age), and a willingness to step back and think as the situation requires. Drilling's a cinch, as the bit will (within reason) tend to seek the center punch hole. Just shift into Zen mode, position the metal and be one with the machine...
As for the effect, well... sometimes things morph into something other than what one plans. In this case I was inspired by a 1950's themed coffeehouse in Albuquerque; lots of '50's-style "googie" retro stuff with a "spaceship" look. Who knows, maybe it'll still work out...
BTW, I noticed you're in Winston-Salem. I lived in the Triad area for nearly 20 years before my work took me out west. I still have lots of friends and family there, and I really miss them - and all the hamfests and CC-AWA swap meets I used to attend.
And that "gummy" metal I described came from D.H Griffin in Greensboro - where I also once purchased 10 old Tektronix 'scopes for $1 per pound! Ah, the good old days...
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$1 a #... that's.... $47,000!
I remember some of your posts from your GBO days, too. Been quite a while.
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One more post and a trial fitting before (finally) getting on to the electronic stuff!
Here's two views of what the final product will look like. You'll notice I've attached the pedestal assemblies to the main chassis frame, and also added 3/8" "feet" to raise the whole deal up for ventilation. Right now the amp is just sitting on those thin discs, but they'll be screwed to the pedestals before it's all finished.
I've also given the entire frame a coat of nitrocellulose sanding sealer, which (if you're unfamiliar with wood finishes) is a noxious lacquer with solids added to fill the pores in wood. It'll be sanded down almost to nothing before the final topcoats are applied, but here you get an idea of why I used the wood I did. The lacquer really brings out the figure in that Bubinga!
Turns out I was fortunate to have bought this stuff when I did, 'cause Bubinga ain't cheap; like around $12 per board foot. And that's for the run-of-the-mill non-figured stuff. I know this because yesterday I searched in vain for more like this at my usual hardwood joints. Plenty out there, but absolutely nothing this nice. Poo.
So now that my crapentry is complete, I'm free to focus on the following:
Here's two views of what the final product will look like. You'll notice I've attached the pedestal assemblies to the main chassis frame, and also added 3/8" "feet" to raise the whole deal up for ventilation. Right now the amp is just sitting on those thin discs, but they'll be screwed to the pedestals before it's all finished.
I've also given the entire frame a coat of nitrocellulose sanding sealer, which (if you're unfamiliar with wood finishes) is a noxious lacquer with solids added to fill the pores in wood. It'll be sanded down almost to nothing before the final topcoats are applied, but here you get an idea of why I used the wood I did. The lacquer really brings out the figure in that Bubinga!
Turns out I was fortunate to have bought this stuff when I did, 'cause Bubinga ain't cheap; like around $12 per board foot. And that's for the run-of-the-mill non-figured stuff. I know this because yesterday I searched in vain for more like this at my usual hardwood joints. Plenty out there, but absolutely nothing this nice. Poo.
So now that my crapentry is complete, I'm free to focus on the following:
- Creating power "vias" between the power supply and amplifier sections
- Finalizing the power supply mechanicals
- Power Supply assembly and bench testing
- Finalizing the mechanicals for the amplifier section.
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Question for those wiser than myself...
Before I proceed further, I'd like to ask for some advice from fellow forum members.
Bearing in mind that I'm building this amp for my own personal use (and therefore not as a UL-listed device for sale to the general public), I'm wondering if I could take a page from the past and build some small turret-board type assemblies using dense wood as a substrate. Note: If this comes close to violating any safety rule in this forum, then I'll be glad to end this particular discussion here and now. Otherwise...
What I'm proposing isn't that far-fetched; look up some of the old ham radio transmitters and receivers from the '20's through the '50's and you'll see what I mean. Many of these old designs were built on wooden breadboards that used small screws as binding posts, and not a few used voltages far higher than what's seen in the RLD. I've built six or seven of these myself through the years, but here's my rationale for their use in this particular build:
Before I proceed further, I'd like to ask for some advice from fellow forum members.
Bearing in mind that I'm building this amp for my own personal use (and therefore not as a UL-listed device for sale to the general public), I'm wondering if I could take a page from the past and build some small turret-board type assemblies using dense wood as a substrate. Note: If this comes close to violating any safety rule in this forum, then I'll be glad to end this particular discussion here and now. Otherwise...
What I'm proposing isn't that far-fetched; look up some of the old ham radio transmitters and receivers from the '20's through the '50's and you'll see what I mean. Many of these old designs were built on wooden breadboards that used small screws as binding posts, and not a few used voltages far higher than what's seen in the RLD. I've built six or seven of these myself through the years, but here's my rationale for their use in this particular build:
- The interior of the chassis will be well-ventilated, and most of the major heat-producing devices - mainly tubes - are mounted topside.
- All of the parts I've acquired for the build are overrated by a factor of at least 2 in terms of wattage and voltage, minimizing any fire risk.
- With the exception of the regulator heatsinks (which themselves will be larger than necessary), all resistors, transistors, ICs, etc. will be mounted a generous distance from the wooden "boards". Additionally, the assemblies will be mounted in a manner that minimizes the wood's exposure to excessive heat in the event any "magic smoke" is released.
- The wood itself hasn't been decided upon as yet, but it will be a dense species that's not easily ignited.
- Being what it is this amplifier will be used for listening, meaning that it will be attended when in use.
- This route will allow me to achieve several efficiencies in layout, materials and time.
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Hobby circuit perfboard with copper pads... or do you have some other artistic thing in mind that will be visable?
No, nothing artistic at all. It's really an expedient more than anything else; I actually have the materials on hand. I suppose that's just another way of saying I really don't want to have to order yet another item!
"Manhattan" construction is another possibility as I have a bunch of PC board material in my scrap box, but at this point it somehow seems easier to "cut and screw" than "punch and glue".
"Manhattan" construction is another possibility as I have a bunch of PC board material in my scrap box, but at this point it somehow seems easier to "cut and screw" than "punch and glue".
Mr_Zenith, nice build! You hide the wires from power supply to the amp inside the wood frame, to keep the look.
Cool look. Very nice. I like the PS kinda detached from the amp itself. Nice.
The feet look awesome.
Congrats.
The feet look awesome.
Congrats.
Well, I'm not a fan of using anything combustion-able to build electronics on. My personal favorite material to build binding post or turret style circuits on is GP03 red fiberglass board. I purchase it from McMaster Carr along with brass screws and nuts to use as binding post. Makes a nice neat and attractive layout. Best to cut and drill with carbide, the glass fibers are abrasive.
How are you going to run the wires from the PS to the amp side? I'm thinking some polished copper tubes with the wires running inside would look cool.
Should be a beautiful looking amp when your finished.
BillWojo
How are you going to run the wires from the PS to the amp side? I'm thinking some polished copper tubes with the wires running inside would look cool.
Should be a beautiful looking amp when your finished.
BillWojo
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