EMG 81 + 85 control configurations?

[gwhiteside]

I'm swapping a set of EMG 81 and 85 active pickups into my guitar. I've done this I want to say probably three times already, because the original passives have good (different) tone... Yeah, should get a second guitar, but you know, money. Anyway, my guitar's configuration is two pickups, master volume, master tone, and three-way selector switch. And that's how I've always wired both sets of pickups.

Now my question is, would it be possible to ditch the switch and wire this instead with three pots? E.g., two independent volume knobs, one master tone knob? If this is doable, are there any caveats (or "creativity features")? In other words, for a given equivalent tone and volume setting, would it sound and/or behave any different from the two knob, three-way selector setup? I just can't hazard a decent guess as to whether it would work at all if I tried, and if it did work, how it might impact the tone, output, control response, etc., on account of the active electronics.

 

[Metaltastic]

Well not having a switch would mean that you'd have to have the volume of one pickup all the way down to get only the sound of the other, which strikes me as a royal pain in the ass - why not ditch the tone knob and wire it with two volumes? Also, you're changing pots when going from passive to EMG and back, right?

 

[gwhiteside]

you'd have to have the volume of one pickup all the way down to get only the sound of the other, which strikes me as a royal pain in the ass

I definitely see how that could get on somebody else's nerves. My perspective is, I never (and I mean never) ever have occasion to play for or with anyone else, so if I need to fumble for an extra half second to cut or alter my volume it's not even remotely an issue. Or if it was, volume pedal or something I guess. The other thing is that I just don't dig the sounds from my neck EMG, whether I have the 85 or 81 up there. Given the choice between neck, neck + bridge, or bridge, I stay on the bridge 98% of the time. I was thinking if it was possible to configure it so that I could access a whole range of blended tones between the two as opposed to one the other or both... Maybe but a pinch of bridge might change my mind completely about the neck, who knows. I'm just curious about expanding my tone options a bit.

That's a large part of the reason (aside from the coil splits) that I ever bother going back and forth between the two pickup sets in the first place. With my passives, I'll probably use the neck a good 25% of the time.

why not ditch the tone knob and wire it with two volumes?

That's an interesting idea... and certainly possible, being only a resistor and a capacitor away--but I do use the tone knob waaaaaaay more than the neck pickup in the first place, so I'd probably decide against it. Although I could just wire up the two volumes, and stuff the tone pot into the control cavity so it's inconvenient, but not impossible to adjust... That would almost be an acceptable tradeoff. Or hell, maybe cut a piece of plexiglass into the shape of the back cover for the control cavity and mount it to that, so I don't have to destroy the original or try to route my guitar (not that I convincingly could, the existing routes are recessed and fancy-like). Actually I'm kind of digging that; I'm going to look and see if I might have some plexiglass/plastic/whatever laying in my basement or garage right now.

Also, you're changing pots when going from passive to EMG and back, right?

Yes. I'm definitely not "one of those types."

Oh, and I forgot to mention in the first post. For what it's worth, I did manage to dig up this schematic, but it's only a schematic. No explanation of the actual outcome, much less any guarantee that someone didn't simply pull the diagram out of their rear, etc. And I guess at this point it's worth clarifying that no, EMG doesn't offer an official diagram for the configuration I'm describing.

 

[Metaltastic]

That wiring diagram looks like it should work, but I'm far from an expert on the subject - however, now that I realize you're going for blending, how about a blend pot? (along with master volume/tone) And even if you don't play out, I'd still be worried about having a knob protruding from the back of my guitar (referring to the plexiglass cover w/ tone knob idea)

 

[John_C]

That schematic would work fine. Initially it looked like the pots were in series, but on closer inspection it's ok

 

[gwhiteside]

Alright, so here's what I ultimately ended up trying... I took this diagram (an official EMG diagram included with my box set), which is for two pickups, two independent volumes, one master tone, and a three-way switch; I simply omitted the three-way switch, effectively hardwiring it in the middle position. What I did is actually very similar to the first diagram I had posted, but the tone pot is wired differently between the two. I'm thinking about going back in today possibly and trying an A/B comparison; I would guess they sound similar enough but the other way might be more flexible or something because it assumes no switch in the first place. I don't know, that's why I'd try right.

Anyway, having said that, what I did with the official diagram and omitting the three-way switch does indeed work. The tone affects both pickups, and the two volume knobs do control the two pickups independently. The two pickups' volumes seem to blend like this: with both knobs at 0%, there's no output. With one knob at 100%, you get say 1V rms, and if you then bring up the second knob the output stays level but you get more of the second pickup and less of the first. Which makes sense, they're wired in parallel. You can hear some sort of interesting phase effect as you blend or cut the second pickup. To get the most dramatic effect, I seated the bridge pickup like a hair from the strings like I usually do, but dropped the neck about as far into the body as I could go. Overall, it turned out cool I would have to say. Especially for having three holes to work with (that's what she said?). If I do go back in to try a different wiring, I might even try with the switch again and make some quick recordings to see if and how the sound of the active electronics compares between the different wirings, because I can't seem to find much useful information or examples on how different control wirings for a given guitar for a given set of pickups alters tone. It's mostly between two guitars, or two different sets of pickups.

And since it's not really necessary, here are a couple of pictures with a crappy camera:

It's a Schecter C-1 Elite. I have the EMG 81 and 85 installed, and the two silvery-looking knobs at the top control the independent volumes. The stock abalone-top knob near the bottom is the tone.

And even closer in, it's still hard to tell with the crappy camera that the top two volume knobs are, in fact, those little novelty skull knobs:

Anyway, if I get around to wiring in the other two configurations all in one day I'll be sure to record clips for a very limited comparison because again, I can't seem to find anything else in that vein. In the meantime, thanks for the suggestions and letting me bounce ideas around guys, much appreciated!

 

[Executioner213]

Having your bridge pickup that high, don't you get the high-pitched grind noise from your strings touching the pickup when you do any sort of palm mute at all??

 

[gwhiteside]

Having your bridge pickup that high, don't you get the high-pitched grind noise from your strings touching the pickup when you do any sort of palm mute at all??

Hmm, it's not much of a problem for me. The way I've always adjusted that is to hold the string at the 24th fret (which is the lowest the string goes), raise the bridge pickup until it bumps the string, then back it off by a half-turn or so on the screw. Once the strings ring freely at the 24th fret I never press hard enough to cause problems. I see what you mean though--if I push down a good deal and pick fairly hard then yeah I can get that sound. For whatever reason my playing style has always had a very light touch so I guess I never noticed the strings hitting unless I specifically tried. In fact, since I never do it accidentally, I've leveraged it to my advantage. Press delicately for small mutes, rest my hand naturally for chunky mutes, and press slightly for string grindy noise to get Gorguts-esque sounds. But yeah, I don't push down too hard, and I don't use anything thicker than .6mm picks--anything bigger and my fingers trip all over the place and I launch picks, etc.

Maybe it's no coincidence. I can see a sort of evolutionary process here. Of all my friends, I used the thinnest picks, so they never wanted to "borrow" mine... When I first started playing, my hands hurt real bad from trying to play fast stuff all over the place so I stopped trying to pick so hard... My first guitar had super-duper-jumbo frets and light strings so anything harder than just barely fretting would bend the notes badly...

Hey, maybe it's not my fault I "play like a sissy girly" after all!