Capacitor composition question

[Somnif]

Ive been wanting to do a Big Muff build for a while now (think its a rite of passage for all us new guys) and I came upon a question concerning the capacitors. I was planning on using the humungous veroboard layout page that iss floating around, that has values for damn near every flavor of Muff thats been ever been produced. It has, in the layout, 8 electrolytic capacitors. The thing is, in the gut shots of the flavor I was hoping to build (the 73 rams head model), there does not appear to be any electro's at all. Not to mention some of the funkier cap values dont seem to exist in electrolytic form (specifically the 0.15uF leading to the sustain pot)

So my question is, can one swap in a ceramic/film cap for what is, on the layout, an electro. Or should I just get whatever value is closest that I can find and live with "close enough". Any advice would really be appreciated.

vero layout: http://farm8.staticflickr.com/7201/6841035924_666037bcff_o.png
vintage gut shot (from kit rae's site): http://www.kitrae.net/music/Violet%20rams%20board.jpg Are those brick colored blobs some strange form of 1970s electrolytic?

[crane]

I would say that Muff is not the best first build project. It's quite complicated for a beginner - 4 transistors and 3 knobs - lot of parts and wiring to do wrong. On the other hand it's 100% doable, if you are carefull enough.
About the caps - there are many different variations of muff schematic. You can choose whichever you prefer.
I'd suggest you to stay away from electrolytic caps in signal path and use metal film instead.
If you want to stick to those "weird" oldschool values liek 1.5uF you can get them by combining 1uF and 0.47uF in parallel.

[Somnif]

Thanks for the advice! Its not my first pedal, Ive done a LPB-1 clone and a pt2399 delay kit, its just the first pedal where ive had so many options and choices to make. I remember the basic theory of resistors/caps/etc from back in physics, but translating a schematic to a layout is still somewhat mind boggling, and figuring out just what each bit of the circuit does is still a bit voodoo-ish to me unless its painted in bright bold colors for me. But hey we all have to start somewhere, and Im having a hell of a lot of fun in the process.

[crane]

As far as my research said - Rams version is covered in myths. I've built a GGG version which is supposed to be close to Rams one, but is well documented. I've also Modded two Russian big muff pi into GGG version and both of the owners loved'em.
Good luck!

[PRR]

> can one swap in a ceramic/film cap for what is, on the layout, an electro

Yes.

You may find, for values of 1uFd and over, that a film cap is too big or too costly to be practical.... that's why we use electrolytics.

That vero-plan does appear to show polarized caps; but in most places that is absurd. I suspect the artist was copy/pasting the one cap-image.

> Are those brick colored blobs some strange form of 1970s electrolytic?

No; they are film-caps.

[Somnif]

> Are those brick colored blobs some strange form of 1970s electrolytic?
No; they are film-caps.

Thanks for the advice. I assumed they were film, they certainly look it, but they also have what appears to be a polarization mark on them. Given EH's penchant for using mysterious, never seen before or since parts I was just curious.

[PRR]

Film caps traditionally have a mark for "outside foil". In radio circuits, it may matter. In audio, some cork-sniffers say it makes a difference, but this is dubious. It also is not clear which way is best.

> EH's penchant for using mysterious, never seen before or since parts

AFAIK, Mike mostly just took what he could get at a good price. On the older production, E-H was in an area with lots of much bigger electronics factories. He could have been buying odd-lot leftovers from B-47 retrofit contracts, or parts which turned out to be unreliable in 250V operation (9V is different).

However the brown resin-dip film caps are modestly common in 1950s-1970s US production. The only thing is, they are "too good" (too costly) for a 9V fuzzbox. Which probably means someone needed 8,000 for a high-class contract, the distributor ordered 10,000, and Mike caught the close-out sale.

[Mac Walker]

Don't know if there is a more recent layout than the one you linked to, but C4 is shorted out by the jumper to the left.  Handy comparison chart, though....

[Somnif]

Don't know if there is a more recent layout than the one you linked to, but C4 is shorted out by the jumper to the left.  Handy comparison chart, though....

No there isnt any update to that particular layout, at least not yet, but I love being able to see which bits differ from spec to spec. I found a more compact layout I think I'll will use instead though. Based on the same schematic (kit rae's to be exact) just put together a bit differently (standing resistors and whatnot). Bought the parts tonight and once they arrive from thailand should be good to go! (I love tayda, 250~ item order and less than 14$ with shipping)

I really appreciate all the help and advice you folks have been handing out, thanks again!