Hi,
I'm trying to plan construction of an AC30-like guitar head. I have some questions about the chassis construction.
1. Will an aluminum chassis such as BUD Industries AC-427 support iron parts without issue?
2. Can the physical properties of the chassis make microphonics worse? Is this something to be thinking about?
3. If I have 2 rows of pots, is it ok to squeeze them in a 4" tall chassis? (I don't see why not, but I haven't seen it done and it would be hard to change so I want to be sure.)
4. Is there a recommended way to build an amplifier head with all this stuff that is normally sticking out the top so that it can be mounted on a 19" rack? Would this cause heat problems?
I'm trying to plan construction of an AC30-like guitar head. I have some questions about the chassis construction.
1. Will an aluminum chassis such as BUD Industries AC-427 support iron parts without issue?
2. Can the physical properties of the chassis make microphonics worse? Is this something to be thinking about?
3. If I have 2 rows of pots, is it ok to squeeze them in a 4" tall chassis? (I don't see why not, but I haven't seen it done and it would be hard to change so I want to be sure.)
4. Is there a recommended way to build an amplifier head with all this stuff that is normally sticking out the top so that it can be mounted on a 19" rack? Would this cause heat problems?
If your hot parts are inside, you can put two holes in the back and cover them with steel mesh. Put a fan over one. If you can make the grill pretty you can exhaust the heat out a hole in the front.
+1 on ventilation.
Also see Fredde79's bass preamp
Also see Fredde79's bass preamp
An externally hosted image should be here but it was not working when we last tested it.
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Not sure your iron, at least the PT, can fit inside a 4" chassis.
Stated in fine print .04" aluminum is too thin for transformers, fine for general purpose lighter use such as Preamps,EQs, etc.
Brochure is on the verge of lying but getting away with it:
a) .05ga is prominently displayed. No such a thing as .05ga exists. it´s either "some-whole-number" ga such as 16ga, 22ga, etc. or it´s some fraction of an inch, such as 1/8" or a decimal fraction such as .05" or 50 mils, but such unit salad as shown does not actually mean anything.
And when they mention inches it´s .04 and not .05
b) if chassis had TIG welded edges it would be very strong, but they mention spot welding.
Simple and strong on Iron chassis, not that much on Aluminum for multiple reasons.
c) and what´s that nonsense about "Government approved machines"????
If they intend you to think they have some wonderful machinery, I doubt so.
Of course *any and all* mains powered machines must be "Government approved" , meaning they meet certain standards, or they can´t be sold.
That $29 drill you bought at Walmart certainly must meet "government" safety standards, just to mention one of them.
Does it make it "special"???
Stated in fine print .04" aluminum is too thin for transformers, fine for general purpose lighter use such as Preamps,EQs, etc.
Brochure is on the verge of lying but getting away with it:
a) .05ga is prominently displayed. No such a thing as .05ga exists. it´s either "some-whole-number" ga such as 16ga, 22ga, etc. or it´s some fraction of an inch, such as 1/8" or a decimal fraction such as .05" or 50 mils, but such unit salad as shown does not actually mean anything.
And when they mention inches it´s .04 and not .05
b) if chassis had TIG welded edges it would be very strong, but they mention spot welding.
Simple and strong on Iron chassis, not that much on Aluminum for multiple reasons.
c) and what´s that nonsense about "Government approved machines"????
If they intend you to think they have some wonderful machinery, I doubt so.
Of course *any and all* mains powered machines must be "Government approved" , meaning they meet certain standards, or they can´t be sold.
That $29 drill you bought at Walmart certainly must meet "government" safety standards, just to mention one of them.
Does it make it "special"???
> No such a thing as .05ga exists.
That's a typo by some low-paid worker in Allied.
Get the PDF. The AC-series boxes are made in two thicknesses depending on chassis size. The AC-427 is listed as "gauge: 0.050". Clearly not one of the old arbitrary number gauges. In context (BUD is an old-line _US_ maker), it has to be 0.050 Inches.
chaerin seems unsure about mixing metals. On a boat, yes iron and aluminum together will rot each other. On electronics in dry rooms, we do it all the time.
I would use that chassis for an AC30 for an at-home amp, even some studio work. I would not throw it in the back of the Econoline for my Maine to Buenos Aires tour-- the aluminum will crack from the constant jolts.
I would not expect it to be sturdy when hung by its ears in a rack, unless there are steel or thick aluminum rack ears supporting the whole side of the chassis. No, I'd not be sure AC30 size transformers would fit in a 4" tall rack box.
Better rack boxes ARE available.
While two rows of pots will fit in 4", you will get frustrated wiring them in place.
Overall this project may be rather advanced for someone who has not built several amplifiers already. I would suggest a Champ on a for-Champ chassis (or a Brit equivalent if that's your thing). I've scratch-built a fair amount of PA gear, but I found that doing a good job on a Champ (somewhat hot-rodded, but not complicated) was more work than I thought.
That's a typo by some low-paid worker in Allied.
Get the PDF. The AC-series boxes are made in two thicknesses depending on chassis size. The AC-427 is listed as "gauge: 0.050". Clearly not one of the old arbitrary number gauges. In context (BUD is an old-line _US_ maker), it has to be 0.050 Inches.
chaerin seems unsure about mixing metals. On a boat, yes iron and aluminum together will rot each other. On electronics in dry rooms, we do it all the time.
I would use that chassis for an AC30 for an at-home amp, even some studio work. I would not throw it in the back of the Econoline for my Maine to Buenos Aires tour-- the aluminum will crack from the constant jolts.
I would not expect it to be sturdy when hung by its ears in a rack, unless there are steel or thick aluminum rack ears supporting the whole side of the chassis. No, I'd not be sure AC30 size transformers would fit in a 4" tall rack box.
Better rack boxes ARE available.
While two rows of pots will fit in 4", you will get frustrated wiring them in place.
Overall this project may be rather advanced for someone who has not built several amplifiers already. I would suggest a Champ on a for-Champ chassis (or a Brit equivalent if that's your thing). I've scratch-built a fair amount of PA gear, but I found that doing a good job on a Champ (somewhat hot-rodded, but not complicated) was more work than I thought.
My post may have been a bit misleading. I was mostly thinking about ways to rack mount a common layout. Maybe my question is better phrased as, "if I ignore questions about rack-mounting, and I manage to build something that actually works, will I regret it afterward, or can I just put it inside of another box or drill some attachments on it".
(Those examples are really cool, and also probably beyond the scope of layout ideas I can confidently personally adapt to a different amplifier.)
What specifications would you look for for back-of-the-econoline? I have pretty much no sense of how sturdy X thickness of aluminum or steel is.
It also feels ambitious to me, well, so much so that I intentionally bought the iron parts first a little while back, so that it will be too late to go back on the idea.
I may or may not succeed, and I am not unrealistic about that. I've found your posts consistently educational, and I don't mean to ignore a warning.
(Those examples are really cool, and also probably beyond the scope of layout ideas I can confidently personally adapt to a different amplifier.)
What specifications would you look for for back-of-the-econoline? I have pretty much no sense of how sturdy X thickness of aluminum or steel is.
It also feels ambitious to me, well, so much so that I intentionally bought the iron parts first a little while back, so that it will be too late to go back on the idea.
I may or may not succeed, and I am not unrealistic about that. I've found your posts consistently educational, and I don't mean to ignore a warning.
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