Correct resistors or Mouser Mix Up? Egodriver.

[murdog47]

Was going through my Mouser order and these did not look right. The resistors on the left are supposed to be 1/4W 10K for the Egodriver.  The resistors on the right are 1/4W 1M for size comparison.  The 10K's look too small to be correct, are they maybe 1/8W? I don't want to get started on the board until I know for sure. Also what is the purpose and pros/cons of the R1 pulldown resistor?

[DutchMF]

Hey Murdog47, those are indeed 1/8-watt resistors, but the good news is that the colored bands say they are 10k ohms, so you can use them anyway. Check this http://www.hobby-hour.com/electronics/resistorcalculator.php out to learn more about the color codes. Might be that Mouser messed up, might also be that you accidentally ordered some 1/8-watt resistors, 'cause their website is tough to navigate.......

Good luck with your Egodriver build, I'm enjoying mine a LOT!!! Let us know how it works out!

Paul

[murdog47]

Cool! Wasn't sure if the 1/8W would make any difference in function or sound. Did you put a pulldown resistor in your Egodriver?

[irmcdermott]

Also what is the purpose and pros/cons of the R1 pulldown resistor?

Taken from the diystompboxes wiki:

"Pops when switching, even with pulldown resistors
From R.G. Keen
There is a weak link in the power/ground setup in most effects using stereo jack switching. You can get pops when switching the relatively high LED current even if you have pulldown resistors on both input and output caps.
The culprit is ground noise. The ground noise happens when the sudden start and/or stop of current in the LED makes the signal ground voltage change suddenly. +9V decoupling may not help, and may make it worse.
The ground noise comes from our friend, the stereo jack ground switch. If your jack is new and the plug is new, things work great. When dirt, oil, crud, bar funk, and other nasties build up on the ground ring of the input jack and the second-channel contact that supplies ground through the plug into the input ground ring, and thence to the effect board, the resistance through that path can get high enough to make a noticeable pop when the LED current starts and stops.
This sudden transient is worse with mechanical switches because they really do go from fully off to milliohms of resistance in zero time when the metals contact. The sudden "ground bounce" can flow right into the input of your effect, and it doesn't take much to hear a pop from the input of a gain-of-a-zillion MegaBlaster."


"Bypass - I get a pop when switching my effect in and out. How do I stop this?
The typical method is to put a "pulldown resistor" from signal to ground at the front and end of your circuit. This is implemented as a 1 meg resistor from signal to ground. Just put one at the beginning of your circuit board (before the input cap or start of circuit if no input cap) and another at the end (after the output cap or end of circuit). Look at the many GEO layouts if you need to see a layout using these resistors. If you are not using high quality switches, it could also be the switch."

[murdog47]

This place is awesome! Thank you!

[DutchMF]

This place is awesome! Thank you!

Yes, it is!  I have a pulldown resistor in mine, and it doesn't pop that much. And since my band is pretty loud, no one realy notices. Be sure to check out www.geofex.com, that's the website from R.G. Keen who jrmcdermott was quoting. It's so full of usefull info concerning pedals it's almost to much.....

Paul

[Fastocker]

Are those 10k resistors KOA Speers?  KOA Speer makes small 1/4-watt resistors that look like 1/8-watt resistors:

http://ca.mouser.com/ProductDetail/KOA-Speer/MFS1-4DLT52R1002F/?qs=sGAEpiMZZMu61qfTUdNhG0gnpvnQT%252b0k6Uglv%2fiVp94%3d

They're 3.2mm long -- I use them all the time for tight Vero builds to get resistors to lie down flat.

[murdog47]

Yep, 10K KOA speer. The Mouser package says 1/4W so that's probably the case.