madbeanpedals::forum

Projects => Tech Help - Projects Page => Topic started by: carbonfreeze on May 06, 2010, 06:26:05 PM

Title: help with switches for Pork Barrel
Post by: carbonfreeze on May 06, 2010, 06:26:05 PM
I'm trying to buy the switches for the mix, depth, and wet controls on the Pork Barrel. They are marked as SPST, but would SPDT work as well, since there's nothing connected to the third lug?

I don't see any SPST at smallbear. Just wondering if I can pick up what's available, or if I need to look elsewhere?


thanks for the help :)
Title: Re: help with switches for Pork Barrel
Post by: mjcyates on May 06, 2010, 07:00:53 PM
You can get them at Radio Shack if you happen to have one close by.
Title: Re: help with switches for Pork Barrel
Post by: madbean on May 06, 2010, 07:28:29 PM
I always use SPDT. You can leave the third lug unconnected, or you can run the wire from the middle lug to the third lug and solder it. It's a little more elegant that way: no floating/unconnected lugs.
Title: Re: help with switches for Pork Barrel
Post by: carbonfreeze on May 06, 2010, 07:55:49 PM
thanks.

also, I"m having trouble locating a 47pf cap. I can find a silver mica on Mouser, but I'm notsure that's what I need. If not, can you point me to the cap for C26? Smallbear or other?
Title: Re: help with switches for Pork Barrel
Post by: madbean on May 06, 2010, 08:27:57 PM
A ceramic will do fine.

http://www.mouser.com/Search/ProductDetail.aspx?R=140-50N5-470J-RCvirtualkey21980000virtualkey140-50N5-470J-RC
Title: Re: help with switches for Pork Barrel
Post by: carbonfreeze on May 06, 2010, 08:31:05 PM
wonderful. Thanks. incidentally, how do you know when to use film, ceramic, or other? I can see when to use electrolytics/polarized from the schem. and layout, but what about the other caps? Fortunately, I can see on your layouts where you use a box cap, but when is it okay to deviate and mix n match cap types?
Title: Re: help with switches for Pork Barrel
Post by: CRBMoA on May 07, 2010, 05:50:11 PM
There are people that swear by one type or another, and others that say any 0.1uf, regardless of composition, will sound the same. I actually have started a double blind test here (http://www.freestompboxes.org/viewtopic.php?f=10&t=8718&hilit=global+capacitor) to try to add to the confusion (erm, information).

In my own experience, no difference. But I have only been doing this for a year and a half.
Title: Re: help with switches for Pork Barrel
Post by: madbean on May 07, 2010, 06:04:01 PM
This is what I use:

Metalized Film (box) for 1n - 470n, and for 1uF if appropriate
Ceramic for all pF values
Xicon High Temp or mini electrolytic caps.
Mix of metal, carbon film, and carbon composition.

You can absolutely mix any types together. It just depends on what you have available and what you feel like spending money on.