View Full Version : Wiring question for LP Jr. with two P90s
02-27-2011, 07:32 PM
I'm sure this is covered elsewhere in here, but I can't quite find the whole shebang in one thread.
I see three different ways I could wire up my LP Jr. This from Acme shows the capacitors stretching between the volume and tone pot in two different ways, corresponding to Modern and Vintage.
Then there's the Seymour Duncan version, where the cap attaches only to the tone pot.
I think the Acme diagrams do a nice job of describing the differences in their two approaches, but I'm wondering how the Duncan approach differs tonally or if it's essentially the same as one of the two Acmes.
02-28-2011, 06:15 AM
The Duncan diagram is "Modern" wiring. Whether the cap comes before the pot or after it on the way to ground makes no difference.
And yes, the Acme write up is excellent. Covers all the bases and is very even handed.
02-28-2011, 08:22 AM
. Whether the cap comes before the pot or after it on the way to ground makes no difference.
The tone pot, that is.
All that matters is which lug of the volume pot gets the connection to the cap, however that happens. The clockwise lug is "normal", the center lug is "'50s".
02-28-2011, 08:56 AM
Thanks to both of you stalwart posters. I suspect you'd pick one modern over the other (Acme or Duncan) based on the physical size of your cap? I mean, a big beefy Sprague isn't going to fit between the pot belly and the middle lug, so you'd do the Acme setup just to have room for its length?
02-28-2011, 12:26 PM
I pretty much always do it Acme/Gibson style because I don't like soldering to pot casings.
And since you didn't ask, I prefer modern wiring. ;)
02-28-2011, 12:43 PM
Both wiring methods do the same thing. The 50's version was used because back then, the caps were big and it helped keep the pots aligned. They would actually do all the interconnect wiring on a fixture then transfer the whole assembly into the instrument and connect the pickups and bridge ground. Either way is going to work fine. You want a twist? Change the tone pot from an audio/log taper pot to a linear taper pot. You'll get a smooth transition through the range of the tone control.
02-28-2011, 08:46 PM
Both wiring methods do the same thing... You want a twist? Change the tone pot from an audio/log taper pot to a linear taper pot. You'll get a smooth transition through the range of the tone control.
allow me to quibble...
'50s wiring will actually act differently if both the volume and the tone are turned down; it'll become annoyingly interactive, with the volume pot now dropping off way faster from "10", and the tone pot not getting dark until much lower on the dial.
"modern" wiring allows each pot to behave the same no matter where the other one is set.
as for linear tones, you'll find they actually act like switches, not making any change until they're almost all the way down.
think about it; a 500k linear tone would have to be turned halfway down just to get to the point of sounding like a 250k tone on "10", and 4/5ths of the way down ("2" on the knob) just to get to the point of sounding like an '80s gibson 100k tone pot on "10".
that's 80% of its rotation for just a subtle difference in high end, leaving all the real change to happen between "2" and "0".
linear volumes are cool for bass guitar, and for bone-dry uncompressed jazz guitar, but linear tones are pretty much useless.
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