Pickup blend switch with variable blend.

SUBass · #1 05-09-2011, 07:21 AM

I was playing around with my bass last night that has two J pickups with a VV configuration (No tone...Who needs that?!). Like many people, I find three tones particularly useful, full on both pickups, full on bridge with the neck a little back, full on neck with the bridge a little back. Rarely do I go for just bridge or neck...But you never know.

Sooo...I thought about putting in a five position rotary switch and since I wasn't sure what values I needed for the "little bit back" of each pickup...I thought about using a trimmer pot. The idea being that position 1 is neck, position 3 is both and position 5 is bridge (depending on how you look at it). Position 2 would be full on neck with a little bit of bridge as determined by a trimmer. Likewise, position 4 would be full on bridge with a little bit of neck. The amount of bridge/neck in the "in-between" settings is fully adjustable but would be a set it and forget it kind of thing.

Anyway...Attached is the circuit I came up with. It's kind of a "unloaded blend" but with switches for "presets."

Thoughts? I always have to ask if I'm missing something obvious here like some sort of goofy interaction that flew past my first go-over.

BrickBatMansion · #2 05-09-2011, 07:27 AM

dont know 'bout the electronics side of it but it sounds like a great idea. i think your cheating yourself tho not having a tone control. even more sounds! make this project happen. i think it would be great.

**line6man** · #3 05-09-2011, 11:04 AM

Someone suggests this idea every once in a while, and while it's solid in theory, in practice, the concern is trying to find the right volume setting presets to work with every rig in every situation.

You might set up your trimmer pots for the perfect settings, then change amps/rooms/etc, and wish that you could tweak it again, but won't be able to.

SUBass · #4 05-09-2011, 12:04 PM

Hmmm...The two comments I've heard related to this so far are:

If you plug in to a different amp, your settings may not produce the same tone. Which would be understandable if there were a different input impedance on the amp.

And

You won't be able to (easily) change the blend settings.

The first point is not a big deal if there is an active preamp on the bass after the blend config. The other point has validity. While still adjustable...You have to remove the control plate to get to it. Not something that you can do at a moments notice.

Something to ponder.

**line6man** · #5 05-09-2011, 12:16 PM

Quote:

Originally Posted by SUBass

While still adjustable...You have to remove the control plate to get to it.

Not necessarily.
Personally, I would drill small holes in the control plate and mount the trimmer pots behind the holes, so you can adjust them with a screwdriver at any time.

If you really want to get into it, mount recessed thumbwheel pots on the control plate. Make sure they recess enough to not be accidentally adjusted.

Tommorichards · #6 05-09-2011, 02:56 PM

Quote:

Originally Posted by line6man

Not necessarily.
Personally, I would drill small holes in the control plate and mount the trimmer pots behind the holes, so you can adjust them with a screwdriver at any time.

If you really want to get into it, mount recessed thumbwheel pots on the control plate. Make sure they recess enough to not be accidentally adjusted.

I was going to pretty much suggest this. not too bad of an idea

walterw · #7 05-09-2011, 09:03 PM

or, you could have the two trimpots built onto one shaft, turning opposite each other, and put that shaft through the control plate.

an un-grounded blend pot, in other words

darkstorm · #8 05-09-2011, 09:13 PM

You will allways get better more precise as desired pup blending by simply useing seperate vol for each pup rather then trying to use a variblend switch with resitors or mini trim pots on it. Just use volume knobs with marker or the numbered speed knobs to help you get into the areas you most use for how much bridge and neck pup for each voiceing desired. Add 3way switch if you want the quick easy back and forth of either pup solod versus various fave blend settings when useing both pups. Like guitars got. Adding the extra trim pots could also cause you to lose a little bit of upper end sparkle as well imo since more pots can cut treble a little bit.

walterw · #9 05-09-2011, 09:15 PM

or, you could have the two trimpots built onto one shaft, turning opposite each other, and put that shaft through the control plate.

an un-grounded blend pot, in other words

**line6man** · #10 05-09-2011, 09:22 PM

Quote:

Originally Posted by walterw

or, you could have the two trimpots built onto one shaft, turning opposite each other, and put that shaft through the control plate.

an un-grounded blend pot, in other words

We heard you the first time.

walterw · #11 05-09-2011, 09:30 PM

whoops!

that was a posting glitch, not excess smartassey!