[sdiy] Starter Components - Capacitors

[harrybissell]

I stock a wide variety of capacitors...  (well you'd expect that :^)

I would recommend

Mylar (polyester) 5% 50V in as many values as is prectical for you...
from .001uF to .22uF     At a minumum I'd keep

.001uF
.0022uF
.0033uF
.0047uF
.0068uF
.0082uF

and then repeat the same pattern for the .01uF

Additional values will help. If you can afford them, I'd buy the 2% values
instead.
Use these caps for all general audio purposes... especially prototyping. You
can
switch to a polystyrene later if you need it

Polystyrene caps:

Xicon makes two kits, distributed by Mouser... ranging from low pF values to
.01uF
I'd buy one of each

Ceramic caps:

I stock these ONLY in the pf values up to .001uF   Look for NP0 or C0G types
only in these
small sizes. I use

20pF
30pF
50pF
100pF
220pF
500pF
.001uF

For decoupling I use .1uF 50V ceramics...  Z5U or X7R are fine and tolerance
does not matter.   Buy these in really large quantities, and use one on every
power
supply pin on every chip (Right, Jim ???)

Electrolytics

I stock NON POLAR electrolytic caps in

1uF
4.7uF
10uF

I use these for all interstage coupling apps.  Usually these are not too
critical in value.
If these are part of an active filter etc... maybe its a poor design anyway.

Why non-polar ???   With the bipolar supplies we use... it is very tough to
tell what the
applied polarity might be (especially in a modular).

I use Polar electrolytics for power supply uses.  My favorite value is
probably 470uF / 50V  but I have really, really BIG ones if I need them.   If
you don't
design your own power suppies I doubt you'd need anything bigger than the
470uF

Tantalum

I don't use tantalum except in power supply decoupling, and when I'm POSITIVE
that
the supply will not ever get reverse voltage. Tantalums fail shorted, and get
REALLY
hot when they do... they can fry a PCB (or an unlucky finger).   I use

1uF / 50V
10uF / 35V

Specialty caps:   I keep a bunch of odd capacitors around... some high
voltage types
for across the line applications (these are usually UL listed as "X1" or "X2"
types) for the
USA they are usually 250V (they can be safely run across the AC line)   Folks
in Europe should
ask your buddies over there what is the equivalent.

I keep some Polycarbonate types, metallized film, film and foil etc for those
odd jobs.  Probably
a synth-diyer won't need those.

This is not an exhaustive list.  You can just buy what you need to build a
project, buy MORE to get
the nearest price break and keep the excess.  You'll find that often 100pcs
are only slightly more expensive than 25 pcs. Having an assortment on hand
can make R&D go much smoother.

AVOID buying unmarked "grab-bag" assortments because there is no way you will
be able to find
out what you have.   For decoupling they might be fine, but for serious work
you will never be able
to trust their properties.   A Z5U ceramic in ANYTHING but a really
non-critical spot will give you
major league headaches !!!

H^) harry

James Howe wrote:

> Since I'm fairly new to synth-diy work, and electronics in general, I
> don't have a large amount of electronic components laying around which I
> can use to build things.  From looking at various synth schematics I can
> get a pretty good idea of the types of transistors, diodes, op amps, etc.
> to get.  Resistors are not a big problem either.  However, I'm stumped
> when it comes to capacitors.  There are so many different types, sizes,
> materials, etc. that I'm unsure of what to include in a set of basic
> components to have on hand for building/experimentation purposes.  Can
> anyone recommend a reasonable set of capacitors (size, type, etc) that
> would be good to have on hand for synth work (i.e. building VCO's, VCA's,
> etc.)
>
> Thanks.
>
> --
> James Howe
>
> Contact: http://public.xdi.org/=James.Howe