Pots and amature questions

[cannikin]

Hello everyone, I've been cruising the forum for a couple of weeks, and I just started building a tremolo pedal.  I have a couple of 50K audio pots but the schematic calls for 25K.  Will using a 50K pot work without any issues? Or do I have to make some modifications?

Also, if you don't know the value, what is the best way to test Caps - to find the value.   Is it using a digital Multi-meter?  I have one of those assorted Film Cap boxes, but since they aren't Electrolytics I have no idea what the values are.

Thanks.

[petemoore]

Theres' audio taper and Linear taper [see GEO secret life of pots]
 50k might do well, tag on a 47k resistor across the 50k pot to make a 25k workalike [outside lugs or potlugs 1 and 3].
 As far as caps, I think the cap value checking devices are expensive.
 If they have no code, I just stick 'em in a FF input cap socket and compare sound to known value cap[s...between the code and just listening I can usually figure out what value the cap is, or there abouts.

[KORGULL]

Also, if you don't know the value, what is the best way to test Caps - to find the value. Is it using a digital Multi-meter? I have one of those assorted Film Cap boxes, but since they aren't Electrolytics I have no idea what the values are.

My $40 Radio Shack multi-meter can measure capacitance from 0.5nF up to 40uF - it seems pretty accurate too.
If your caps are marked, it is a simple matter to interpret them and you'll be in business.
If say, 223 is printed on it:
2 is the first number of the value, 2 is the second number of the value, and 3 is the number of zeros (or the multiplier - 0=1, 1=10, 2=100, 3=1000)
So you have 22 times 1000 or just take 22 and add three zeros to it.
The answer is in pico-farads - 22000pF
To convert it to micro-farads divide by 1,000,000 - .022uF
If you see a letter it is the tolerance rating.
The voltage rating is probably on the cap too.

[timwalsh]

Hey here is a site with the full explanation.

http://xtronics.com/kits/ccode.htm

I have the same $40 multimeter from radio shack...bought it because of the capacitance function (cheapest one I could find)  Its good to check them, some of them are pretty high tolerance and can drift pretty far from the nominal value

[Fret Wire]

Here's a $30 beauty:
http://www.electronickits.com/gold/capacitancemeter.htm

Great for double checking values, as well as sorting out odd caps n' such. I have one and find it real usefull.