freestompboxes.org

So I've been reading about basic looper wiring since I came up with a pretty ambitious looper build for a beginner, and I've noticed some discrepancies with different diagrams on the web.

First, I was directed to the very informative Beavis site, and I was looking at his diagrams for loopers. I'll use just one of them for reference:



My question is, why did he wire the input signal like that instead of just using one connection to the center row of poles and jumping the necessary bottom poles like this?:



The latter seems like a much simpler design and cleaner. Just curious why Beavis would choose to wire his up like that since it looks to my recently educated eyes that it would get the same result. And is there any reason he wired the negative lead of the LED to the switch instead of the other way around like in the latter picture, and even so isn't that ground wire jumping poles 6 & 7 redundant? That's at least how it looks to me and if anyone could explain why that isn't the case it would probably blow my mind.

And LASTLY, why in the latter diagram is he using a stereo jack for the FX SEND? It looks like he's just using the RING connector as a ground point for the battery. Is that just to cut power from the battery when nothing is plugged into it to prevent drain?

Thanks in advance!

digitalzombie wrote:and I've noticed some discrepancies with different diagrams on the web.

There's lots of ways to wire a 3PDT.

My question is, why did he wire the input signal like that instead of just using one connection to the center row of poles and jumping the necessary bottom poles like this?:

There's lots of ways to wire a 3PDT: I personally prefer the latter (Aron Nelson) "bypass arrangement" with the bypass going from lug 7 to 9 (aesthetically), but I prefer Beavis's LED-wiring arrangement (i.e grounding the negative end of the LED with the switch), for the reason below -

is there any reason he wired the negative lead of the LED to the switch instead of the other way around like in the latter picture, and even so isn't that ground wire jumping poles 6 & 7 redundant?

By using the making and breaking a connection to ground to switch the LED on and off, Beavis's grounded lug 7 grounds the input of the loop so it's not "floating" when not in use, reducing the chance of any oscillation or noise from high gain circuit. Many people use this method routinely in all their builds (me included), i.e. ground the input of the circuit in bypass. Not sure if it's entirely neccessary, but that lug would go unused otherwise, and it eliminates one potential problem source if your circuit is noisy/oscillating in bypass.

And LASTLY, why in the latter diagram is he using a stereo jack for the FX SEND? It looks like he's just using the RING connector as a ground point for the battery. Is that just to cut power from the battery when nothing is plugged into it to prevent drain?

Yes

Also, I think that grounding the input also provides a discharge path for the decoupling capacitor and can help prevent popping (for some pedals where there isn't a pulldown resistor already, for instance).