3PDT Usage

[Chris R]

I recently found that if I leave off the power -> led -> Corner Poll on a 3PDT  i get a nice buzz going when the volume of the guitar is all the way down and the effect is engaged.  Otherwise if the guitar vol is not all the way down every thing works fine. Why does this happen ?

I don't really know how a 3PDT works (what happens inside when the button is pushed).  Maybe if someone could explain that or point me in the right direction.. that would help.

Thanks

C

[ExpAnonColin]

A 3PDT works like any other switch.  Lets see...

When the switch is flipped one way:

T T T
C C C
P P P
N N N
T T T

P=Pulls
C=Connected
T=Throw
N=Not conneted

When it's flipped of clicked the other way:

T T T
N N N
P P P
C C C
T T T

See, nine terminals...  So when it's flipped up, in most cases, the top left and top middle Throws are connected, and the left and middle P's are the input and output, respectively... so when it's "up" the effect is "ofF", but when the switch is "down", the bottom left and middle throws are usually effect return and send, so it's connected through the effect...

Now in terms of the buzz, I'm not totally sure, but I know it doesnt happen to me at all with a DPDT, which is exactly what you're doing (TB - LED = DPDT, TB + LED=3PDT, at least in most cases).

Hope I helped.

-Colin

[Chris R]

Thanks for the Info Colin.

I just assumed that i could leave the power -> led off the last lug... i guess i was mistaken ;p

C

[AllyP]

Why not just use a DPDT?   Saves money on buying 3pDTs when they can be used in othewr projects? :wink: