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DIY Stompboxes => Building your own stompbox => Topic started by: Jayt on April 09, 2011, 04:34:43 PM

Title: Newbie help needed ref caps and resistors
Post by: Jayt on April 09, 2011, 04:34:43 PM
Hi Guys,

Well new here and this is my first post, so I hope its in the right place.

I am building an MXR Envelope filter with a board from Tonepad, and it is my first build.  I have located most parts here in the UK, but cant seem to find the following, could anyone advise me if I can substitue the ones below for different values which are more readily available, without affecting the overall effect?

I need the following:

Caps - 1uf MKT metal film
          0.05uf
Resistors:  5.1m
                22m
                62k

Any help would be apprecaited.

Cheers

JayT
               
Title: Re: Newbie help needed ref caps and resistors
Post by: Hides-His-Eyes on April 09, 2011, 04:45:04 PM
Replacements:

0.05u => 0.047u

5.1M => anything that big

62k => 68K

the others you'll probably have to track down, which suppliers have you checked? bitsbox, musikding.de, doctortweek, even ebay for the odd bits?
Title: Re: Newbie help needed ref caps and resistors
Post by: vendettav on April 09, 2011, 04:46:30 PM
^ that... i'd also say you could get any type of 1uf cap (i guess an electrolytic?)

but then again I don't really pay much attention to the cap materials
Title: Re: Newbie help needed ref caps and resistors
Post by: lopsided on April 09, 2011, 04:54:55 PM
hi,

can't talk about the exact effect. (It always helps to add a link to the schematic you're working with).
For the caps:
-usually 0,05 can be substituted for 0,047
-usually you can change the advised cap material (it can alter the sound in some cases), but be sure to use polarized (mostly electrolytic) caps, only there, where are they asked for
-you can get a bigger cap value from using two (or more) caps when you connect them in parallel

for the resistors
-it sometimes works to have a next closest resistor value you can find (like for pull down resistors)
-you can add resistance by connecting resistors in series

if you're not sure what series and parallel means go:  http://en.wikipedia.org/wiki/Series_and_parallel_circuits#Capacitors
also, check the DIY FAQ for more info on resistors and capacitors

l_s
Title: Re: Newbie help needed ref caps and resistors
Post by: Jayt on April 09, 2011, 04:58:57 PM
Thanks Guys,

Looks like I might have a bit more homework to do, as they say everyday is a schoolday, I will check out the suppliers listed and see what I can find, and let  you know how I get on.  I will also check out the wikipedia link as well, as sounds like something I need to understand.

Cheers

JayT
Title: Re: Newbie help needed ref caps and resistors
Post by: lopsided on April 09, 2011, 05:14:02 PM
don't worry, you will gain knowledge as you work yourself through the first circuits
up to now I could get every part i needed either form my local supplier (www.gme.cz) or at musikding.de
the problem is, some older schematic use non-standardized values, there were also different local standarts , like in some parts of the world they use 47k pots in others 50K and so on.
sometimes the A+B +... = X formula can be used to get the desired value.
It applies for resistors , if you connect them in series, that is like it shows the upper half here http://hades.mech.northwestern.edu/images/5/51/Series_parallel_resistors.gif
And for capacitors, if you connect them in parallel like this http://www.juliantrubin.com/encyclopedia/electricity/series_parallel_circuits_files/301px-Capacitors_in_parallel.png
Title: Re: Newbie help needed ref caps and resistors
Post by: LucifersTrip on April 09, 2011, 06:06:46 PM
you can get close to almost any value cap & resistor by simply putting various combos of the ones you have in parallel & series. this is all you need:
http://www.1728.com/resistrs.htm

Two notes: 1) remember, the formula for parallel resistors is the same for caps in series. 2) If you twist the components together properly, you can fit it into the same spot on your board as one


Title: Re: Newbie help needed ref caps and resistors
Post by: Hides-His-Eyes on April 09, 2011, 07:00:30 PM
Quote from: vendettav on April 09, 2011, 04:46:30 PM
^ that... i'd also say you could get any type of 1uf cap (i guess an electrolytic?)

Generally specifying film means a non-polarised is required
Title: Re: Newbie help needed ref caps and resistors
Post by: vendettav on April 10, 2011, 02:50:04 AM
oh well I didn't know. but hey I did mention I never cared for the materials so I could never know  :icon_mrgreen: