Very new beginner/ questions regarding capacitors

[jlullo]

Hello everyone.  I'm completely new to the world of building effects.  I've been educating myself on everything i can find for the last few weeks, and am about ready to start ordering parts to build the Tube Screamer clone found on the tonepad.com site.  I am going to buy one of the RTS boards (i figured i should start slow), and am in the process of tracking down all of the parts i need.  I've found most on Small Bear's site, but i'm finding some hard to locate (specifically Capacitors).  There are so many choices when looking outside of Small Bear, and I don't know exactly what kind to choose (Polyester, Ceramic, Electrolytic) .  Also, it seems that the voltages change... is this an issue?  what is the standard voltage?

any help would be greatly appreciated!

thanks!

jonathan

[DuncanM]

Firstly, to be safe, capacitors rated 16v or above should be OK. Higher voltages really shouldn't occur in a 9v powered stompbox. The only real difference is that higher rated capacitors will generally be bulkier and more expensive.
Low Voltage Poly Film caps are a good start for values up to about 0.47uF - Electrolytics for 1uF and above (get RADIAL ones - both leads at one end) - ceramic or silver mica for small values (470pF or less).
Some will say that certain types of capacitor impart a "sound" to the circuit - but worry about that later, get something built first.

BTW, Steve at Smallbear uses the terminology mF to mean the same as uF  (i.e. microFarads or 10^-6F)

[darron]

make sure you get a jrc4558D opamp for it
just to get that retro chic

[jlullo]

awesome... thank you so much guys!  that really helped!

Darron, that's what i read and i plan on it!

[petemoore]

Polyester, Ceramic, Electrolytic)
  I used very few Ceramics, none now.
  20% tolerances work fine...i can't really hear value change 'drift' after trying batches of .1uf's...in any one cap position, ie...N/P for me using these for 'target tweekin' circuits, I usually adjust values anyway using 1x or better value differences...[long story,, not that interesting...short story...for a FF I use my 'caps socketted, FF testboard, TS I just use the tone knob.
  Electrolytics are the source for attaining larg-er Uf's values, [the other types generally reach up to about 1uf or so, not above much], so we resort to using the Electro's for positions requiring large-er Uf values, and try to watch their *shorter shelf lives...I QUIT using used 'ol electro's from scrap...just because I figured *this out the hard way...they don't work often enough for my 'newfound' standards.
  Then there's metal film/low tolerance/$$ types..I tried some of these, fancy paint, nice if you've got a position requiring super close tolerances , or so I hear.
  Pretty cool how they let the shorter wave lengths pass with less resistance than longer ones.