How many different Fender tube amp filter capacitor board sizes are out there?

[murrayatuptown]

I ask this vague question after noting there are about 7 options from the Hoffman store with eyelets or turrets.

I am figuring out what it would take to fit a different board in amps with standalone capacitor boards, using metallized polypropylene instead of electrolytics caps.

The cost concerns are solved by waiting 26 years and realizing there are other industries creating economical options.
The size issues depend on the situation.

Main conflict is increased height and a thus a new cover box where applicable.

I have a friend who wants to explore this in one of his amps...he doesn't care about originality but says he can just keep the old board and document his modifications (bringing his work habits home).

I thought it would be a good idea to figure out how many variations among models could be addressed by a minimal number of board designs (thinking ahead).

I see that (some) Carr Amps use MPP for filtering, but integrate them into their point-to-point chassis wiring.

Or we just use perf board and don't discuss it in publuc( (not agitate the 'keep-it-original' purists with such heresy).

Thanks.
Murray

[Tony Bones]

You mean the board under the dog house on BF/SF amps? I thought they all used the same layout... So, the answer to your question is: 1.

Do I win a prize?

[shooter]

I've used these little buggers in a few builds, here's with terminals, I also had Doug build a turret for them, each 47uF 450vdc, ~~ the size of a small thumb

[sluckey]

There are almost as many different cap boards as there are models. I've seen 3 different size/styles of dog houses. And I've seen cap boards with 4, 5, 6, and even 7 caps. If you are considering building one fit'em all universal board, better think again.

[EL34]

As you saw on my web site.


There are this many and maybe some I do not know about yet
https://el34world.com/charts/Schematics/files/fender/FilterCapLayouts2.gif

[EL34]

You can download and view all the Fender cap boards in the .diy library here
https://el34world.com/charts/DiyLayoutCreatorFiles.htm

The files look like this when opened in DIYLC

[PRR]

It's not like tooling to make a car door. You need raw board, lugs/turrets, and tools (saw, drill, press), you can make a totally different utterly-custom board every 5 minutes. Throw your caps on the board. Pencil where the legs hit and how long it must be. Cut drill press.

Doghouses are quite different. If no stock model works, you try hammering metal on a stump. After you mangle some metal you think to cut a heavy steel stamper which will do it RIGHT every time.... but carving heavy steel is hard work and a dying art. Only justified if you need thousands of the same thing.

[MFowler]

Very nice board options Doug.


Mark

[EL34]

Very nice board options Doug.
Mark

I think I have them all covered

[murrayatuptown]

Thank you all.

I have looked into (and given up on) drawn enclosures due to tooling as mentioned above.

Playing around with a press brake to relearn what I forgot from high school.

Yes, definitely re-rethinking the elusive concept of partial-sorta-universal-with-exceptions.

Box/pan brake that can easily navigate multiple bends and height conflicts (grr) is a lot more expensive than a peasant's brake.

Might be easier to make one out of >1 piece of metal than all this metal artisan work.

Then there's the guy I met who used chicken wire & wood.

Thanks

[EL34]

Why now just forget about external filter caps and put them inside the amp?


Way simpler solution

[murrayatuptown]

I don't have a problem putting caps elsewhere, using separate ones instead of multi-section, etc...just thinking about the least destructive way to pull the old board and wire in another...thinking about the logic of changing as little as possible.

None of my projects have pans...just the friend's Pro Reverb.

The board mount method is preferable for the box caps which have short (1/4") heavy (0.060") leads. Some have 4 leads (2 at each end).

I should forget solving the mechanics of multiple amps...there will always be something that's an exception & I should finish projects before starting new ones if I can't count the number of incomplete ones on one hand.

Things are bad if I tell myself that. Next thing I know, I won't know why I started one of them!

[shooter]

I should finish projects before starting new ones

I made it to 18 before I joined the 12 step program, now I only have 2 at a time, AND I finish them