Runoffgroove Peppermill pedal........

[therecordingart]

I was going to build this pedal, but ran into a road block.  I'm a newbie so be gentle.  

The parts list says I need a 250k resistor and a 50k trim.   I can't find a 250k resistor and don't know what a 50k trim is. Is the 50k trim one of the knobs? Also....how do I wire in an on/off swith in their design?

[Hal]

you can make an equivilant resistor with 2 other ones in series/paralell combinations.  

resistors in series add, in parallel, they combine according to 1/rt=1/r1+1/r2+...

a trimpot is a small pot that stays on the board - you set it once, and leave it alone.

[jmusser]

The 50K trimmer pot, is a minature PC mount pot that you usually adjust with a screwdriver. That way, if bias adjustments are a little finicky due to tolerances, you can get the tone where you want it with the trimmer, and not have to bother it again. I'm guessing when you say on/off, that you mean the bypass switch. Normally on all these pedals, you hook the negative of the battery snap up to the ring of the input stereo jack, and that will get your power turned on, when you plug in your guitar to it. The bypass switch allows you to basically short around the effect while you're not playing, and then when you stomp on the DPDT momentary, you engage the effect. You can look on General Guitar Gadgets to see how to wire true bypass. It's in the  "Links" pages here. JD Sleep has it there, and I believe I had an Easy Build schematic on it to on that site. GEO has it on their Site. If you don't have a switch right now, you can just leave it out, and wire the input and output jacks straight off the board. You're effect will just be engaged all the time, sort of "plug and play". If this isn't the information that you were looking for, just let me know, and I'll try to get you straightened out. The FAQs will clear up several things for you too.

[jmusser]

General Guitar Gadgets is found under "Guitar Effects Projects" at the bottom of the second link page, or go to  http://www.generalguitargadgets.com

[Peter Snowberg]

You can "make" a 250K resistor by placing two 470K resistors in parallel, or two 510K resistors in parallel, or with two 100Ks and a single 47K resistor in series. The resulting values to the above combinations are 235K, 255K, and 247K.... all values that are close enough for Rock'n'Roll.

[therecordingart]

Could the 250k be a gain knob by chance and it was listed as a resistor?  There isn't a 250k resistor on the perfboard diagram on the site, and he has a volume knob listed as a resistor, but not the gain knob?!?

[therecordingart]

Ok...I figured out that the 250k is actually a pot.  I'm on small bear's site looking for capacitors and I don't know the difference between uf and mf.

[jmusser]

uf and mf should be the same thing

[MartyB]

CAPS:
0.0022uF = 2n2 = 222
0.022uF  = 22n = 223
0.0068uF = 6n8 = 682
0.047uF  = 47n = 473
1uF  = 1 microfarad polarized (electrolytic)

RESISTORS:
1m   = 1million ohm = brn/blk/grn

1k   = 1000 ohm = brn/blk/red

4k7  = 4700 ohm = yel/ppl/red

100k = 100,000 ohm = brn/blk/yel

8k2  = 8200 ohm = gry/red/red

POTS:
250k lin = 250,000 ohm = 250kB
100k log = 100,000 ohm = 100kA
50k trim = 50,000 ohm miniature/board-mount

HTH
MartyB