Mixing Passive And Active Pickups

[aidanaido]

Hi, I'm currently building a 12/6 string doubleneck guitar but I've run into a problem when wiring.

I want to put a Gibson '57 and Gibson '57 Plus in the twelve string, (these are passive humbuckers).

And I want to put an EMG 81 and EMG 85 in the six string (Active humbuckers).

I also want to fit an EMG PA-2 pre-amp booster to the EMGS.

I have 2 volume and 2 tone pots for the Gibsons (this is an assembled set with a 3-way selector switch and output jack), and 2 volume and 2 tone pots for the EMGs (these came with the EMGs).

I have 2 3-way selector switches.

I would like to have both necks using the same pickup selector switch, and a 3-way selector switch to choose which necks to play.

I've found finding a diagram which uses both active and passive pickups impossible.

I would appriciate any advice or help on this matter, Thanks.

[Hamer Bass Head]

if you use the emg pa-2 preamp on the output of each passive pickup, you can then wire the rest the same as if they were all active. you can even hardwire them to on instead of having the switch taking up space in your control cavity. If it was me, I like control of the mix between neck and bridge pickups so I'd do that, and then use the emg (or similar) 25k pan pots as the volume controls disassemble them and file the nub for the center detent off. from there to the tone controls ( you may want to repeat the previous step for those as well and finally onto the neck selection switch. The pickup selector you are referring to isn't up to the job, you'd need more or less a dual switch (double sets of poles) and I have no idea where you'd get them. maybe you could use 2 minis?

[crafty]

Well, if you want to keep it as simple as possible, all you need is one PA-2 without the on-off switch for the passive twelve-string side. Just wire the passive pickups as normal, then connect their output to the PA-2 input. Then you can use the master switch to switch between the necks or combine their output.

Having another PA-2 on the active side is also a good idea, but you may want to consider the Afterburner instead. It's basically the same thing, but uses a push-pull pot to activate the circuit and you can adjust the gain on the fly.

I'm personally not a huge fan of trying to blend passive components with active components, but it's really not that difficult if you're willing to spend the $$$. I would actually suggest using a 60A bridge and either an 89R or an HA neck on the twelve-string side instead of the '57s, but if you really like the disparity of sound, whatever floats your boat is cool with me.

Edited April 14, 2006 by crafty

[Hamer Bass Head]

Well, if you want to keep it as simple as possible, all you need is one PA-2 without the on-off switch for the passive twelve-string side. Just wire the passive pickups as normal, then connect their output to the PA-2 input. Then you can use the master switch to switch between the necks or combine their output.

Having another PA-2 on the active side is also a good idea, but you may want to consider the Afterburner instead. It's basically the same thing, but uses a push-pull pot to activate the circuit and you can adjust the gain on the fly.

I'm personally not a huge fan of trying to blend passive components with active components, but it's really not that difficult if you're willing to spend the $$$. I would actually suggest using a 60A bridge and either an 89R or an HA neck on the twelve-string side instead of the '57s, but if you really like the disparity of sound, whatever floats your boat is cool with me.

read my reply again... you need 2 pa-2's; not 1 for the active and one for the passive side.... the active's are already active. you need 1 for each passive pickup to be able to bring them to the correct output and impedance to use them in the rest of the guitar's circuit, using the standard emg-ready 25k pots. also by doing it this way you won' get a nasty pop when switching between the pickups as the preamps are before any switching.

[lovekraft]

Impedance matching passive pickups to 25K control pots is literally as simple as three resistors, one N-channel JFET and two caps per pickup, since you've already got a battery in there to run the EMGs. There's a slightly more complex (but decidedly better) circuit here:

Simple General Purpose Low-noise Impedance Buffer

Of course, if you don't do electronics, you're at the mercy of those who do, and will have to purchase the EMG gear described above.

[ansil]

correct me if i am wrong but did he say he wanted to use both necks at the same time. if not then hmmm why worry.? passive on twelve string and active on six string.

i dont' see a problem

[crafty]

read my reply again... you need 2 pa-2's; not 1 for the active and one for the passive side.... the active's are already active. you need 1 for each passive pickup to be able to bring them to the correct output and impedance to use them in the rest of the guitar's circuit, using the standard emg-ready 25k pots. also by doing it this way you won' get a nasty pop when switching between the pickups as the preamps are before any switching.

Um, sorry, but your way isn't the only way to do it. You CAN wire up the passive side using one PA-2 if you're using separate controls for each side, which he is doing. Also, he stated that he was thinking about putting a PA-2 on the active side as well to utilize the boost function on the actives.

Ansil, I agree that it would be simpler to keep the passive and active side separate, but he mentioned using a 3-way switch to select the necks, so I was just assuming he'd want to blend the two in the middle position like the EDS-1275.

[aidanaido]

Hi, thanks for your responses.

I've looked at the diagram lovekraft supplied but I'm at a loss as to where to begin at it.

I'm wondering is it anyway possible to wire this guitar using one PA-2 switch, or do I need two?

I don't want to lose any sound quality on either neck and I've heard this could happen to the passives if I use the EMGs.

I would prefere to put both necks through the one set of pots.

I want to be able to play both necks at once, so I will need a 3-way switch for that -I've never heard of a dual switch (double sets of poles), you also suggested using two minis for the neck selection, how do both the dual switch and the minis work? Is it possible to use a normal 3-way switch instead?

Ideally, I'd like the simplist solution possible, can I wire the EMGs to the neck selector, wire the pa-2 to the passives, passives to the neck selector, then to the pickup selector, then through the 4 25K EMG pots, and through the EMG output jack?

Perhaps having a pickup selector for each neck would be easier?

Or maby a second set of pots for the passives?

As you can see I'm totally lost as to what to do here, Thanks for your help.

[lovekraft]

How 'bout this? Wire each neck separately, with a regular Gibson toggle for each, and use 500K pots for the passives and 25K pots for the EMGs, then run the output of the passive side to the PA-2 and run that output and the EMG side output to a third neck selector toggle, and whatever master controls you decide to incorporate. Adjust the PA-2 gain to balance the actives and passives.

[Hamer Bass Head]

How 'bout this? Wire each neck separately, with a regular Gibson toggle for each, and use 500K pots for the passives and 25K pots for the EMGs, then run the output of the passive side to the PA-2 and run that output and the EMG side output to a third neck selector toggle, and whatever master controls you decide to incorporate. Adjust the PA-2 gain to balance the actives and passives.

3 selector switches? + 4 pots?!!! this thing will look like an aircraft cockpit when we're done!

I am looking at this from a couple of perspectives: as a musician who gigs, and doesn't want to cut holes all over an instrument... especially considering the time and/or money I've already invested (hardware alone for a doubleneck isn't cheap!) as a father and husband with a job who doesn't have unlimited time to complete a project (hence using emg pre-made stuff rather than etching my own board, hunting for components, trying to make it as silent as possible....you get the idea.).

Anyway here's the simple and relatively pretty solution

Wire the emg's, 1 to each of the upper portions of 2 concentric 25k volume controls.

Next wire the passives each to the 2 emg pa-2 preamps. wire the output of each of those

to the lower corresponding part of each concentric volume control. I assume you want tonal flexibility

so connect the outputs of the passive's and active's volumes to the corresponding connections on a third concentric control (active upper, passive lower) and add the capacitor you want to use for each.

Wire the output of the tone controls to 1 three-way switch, then onto the output jack.... 4 holes only, if you want to change something you won't have unsightly "ventilation-holes" all over the top of your guitar...and you can go to the store, get the parts you need and put this together and test it in an afternoon.

Oh and by the way it works. I own a doubleneck hamer bass and although it's running full active now, in the past the 8-string neck was passive , and several of my other basses are hybrid passive/active circuits like this.

Good Luck,

Bill

[crafty]

How 'bout this? Wire each neck separately, with a regular Gibson toggle for each, and use 500K pots for the passives and 25K pots for the EMGs, then run the output of the passive side to the PA-2 and run that output and the EMG side output to a third neck selector toggle, and whatever master controls you decide to incorporate. Adjust the PA-2 gain to balance the actives and passives.

3 selector switches? + 4 pots?!!! this thing will look like an aircraft cockpit when we're done!

I am looking at this from a couple of perspectives: as a musician who gigs, and doesn't want to cut holes all over an instrument... especially considering the time and/or money I've already invested (hardware alone for a doubleneck isn't cheap!) as a father and husband with a job who doesn't have unlimited time to complete a project (hence using emg pre-made stuff rather than etching my own board, hunting for components, trying to make it as silent as possible....you get the idea.).

Anyway here's the simple and relatively pretty solution

Wire the emg's, 1 to each of the upper portions of 2 concentric 25k volume controls.

Next wire the passives each to the 2 emg pa-2 preamps. wire the output of each of those

to the lower corresponding part of each concentric volume control. I assume you want tonal flexibility

so connect the outputs of the passive's and active's volumes to the corresponding connections on a third concentric control (active upper, passive lower) and add the capacitor you want to use for each.

Wire the output of the tone controls to 1 three-way switch, then onto the output jack.... 4 holes only, if you want to change something you won't have unsightly "ventilation-holes" all over the top of your guitar...and you can go to the store, get the parts you need and put this together and test it in an afternoon.

Oh and by the way it works. I own a doubleneck hamer bass and although it's running full active now, in the past the 8-string neck was passive , and several of my other basses are hybrid passive/active circuits like this.

Good Luck,

Bill

No, you're looking at it from the perspective of someone who think's he a know-it-all, and has no concern about the amount of money you're going to be throwing at the thing. Putting a PA-2 on each passive pickup is a WASTE OF MONEY. Three concentric pots and a second, completely unecessary PA-2 will cost more than the four regular pots and three switches. I know bassists LOVE all their concentric pots and all that, but it's not the best or the simplest way to do it at all.

Edited April 17, 2006 by crafty

[lovekraft]

3 selector switches? + 4 pots?!!!

Too complex for ya? Gee, Jimmy Page always managed to make that work on his EDS1275, even after several bottles of Jack Daniels! Obviously they don't make "musicians who gig" quite like they used to. FWIW, Gibson's been selling that axe configured that way since 1958, so while it may not be optimal, it's damn sure proved both workable and marketable. You simply can't say that a control configuration that's been selling for over 40 years doesn't work! Besides, just as crafty says, that second PA-2 will cost you as much as all the other hardware combined.

I know bassists LOVE all their concentric pots and all that...

Woah, ease up! Some of us understand the K*I*S*S principle - please don't tar me with that brush!

[Hamer Bass Head]

How 'bout this? Wire each neck separately, with a regular Gibson toggle for each, and use 500K pots for the passives and 25K pots for the EMGs, then run the output of the passive side to the PA-2 and run that output and the EMG side output to a third neck selector toggle, and whatever master controls you decide to incorporate. Adjust the PA-2 gain to balance the actives and passives.

looking back at this maybe you're right; but to get the volume/tone control flexibility that Jimmy Page has on his you would need:

2 each 500k for volume for the passives

2 each 500k for the tone controls of the passives

2 each 25k for the emg volumes

2 each for the emg tone controls

3 toggle switches....

and the pa-2

k.i.s.s. indeed..........

but you're right...do whatever you want.

maybe you should lay off his jack daniels when designing guitar circuits!

Edited April 17, 2006 by Hamer Bass Head

[lovekraft]

...maybe you should lay off his jack daniels when designing guitar circuits!

Good shot, but off the mark. Pay attention, so I don't have to repeat myself - Page drank Jack Daniels, I'm a single malt man and whatever you've been indulging in has given you delusions of grandeur.

A dual concentric control is the same as 2 pots, from every standpoint except the number of holes in the guitar top - if you're obsessed with a "cleaner" control layout, that's fine, but it's your obsession, and while your solution may be "pretty", it's far from simple. It's still not necessary to use 2 PA-2s, since you can use one single preamp after the passive pickups' volume pot(s) for the same results. Beyond that, the only differences between what I proposed and your "superior design is that you specified dual concentrics and neglected to include a neck selector switch (which was , incidently, specified in the original poster's spec). As for switch popping, a simple 10Meg pulldown resistor on the PA-2's input will eliminate that problem, if it is indeed a problem, without any audible tone loss. Since except for your misplaced (and redundant) PA-2 and the omitted neck selector switch, both solutions are virtually electrically and sonically identical, I maintain that my circuit is simpler. As for the issue of dual concentrics vs two discrete pots, that's a strictly cosmetic issue and a purely personal choice, so it doesn't interest me at all.

As one gigging bass player (and a husband, and a grandfather) to another, you obviously know more than a little about how this stuff works, and it's always good to have another qualified solderhead around, but you might want to ramp the attitude down just a little, since it's not winning you any new friends around here. But that's just me, and I can be safely ignored, so long as you don't break the rules, so consider it a suggestion.

[ansil]

man i was depressed then i read this thread and got tickled thanks guys. lol

you know if you are half way decent at soldering you could always build a simple single transistor preamp for the passive side cheaper than the emg booster.

[Hamer Bass Head]

...maybe you should lay off his jack daniels when designing guitar circuits!

Good shot, but off the mark. Pay attention, so I don't have to repeat myself - Page drank Jack Daniels, I'm a single malt man and whatever you've been indulging in has given you delusions of grandeur.

A dual concentric control is the same as 2 pots, from every standpoint except the number of holes in the guitar top - if you're obsessed with a "cleaner" control layout, that's fine, but it's your obsession, and while your solution may be "pretty", it's far from simple. It's still not necessary to use 2 PA-2s, since you can use one single preamp after the passive pickups' volume pot(s) for the same results. Beyond that, the only differences between what I proposed and your "superior design is that you specified dual concentrics and neglected to include a neck selector switch (which was , incidently, specified in the original poster's spec). As for switch popping, a simple 10Meg pulldown resistor on the PA-2's input will eliminate that problem, if it is indeed a problem, without any audible tone loss. Since except for your misplaced (and redundant) PA-2 and the omitted neck selector switch, both solutions are virtually electrically and sonically identical, I maintain that my circuit is simpler. As for the issue of dual concentrics vs two discrete pots, that's a strictly cosmetic issue and a purely personal choice, so it doesn't interest me at all.

As one gigging bass player (and a husband, and a grandfather) to another, you obviously know more than a little about how this stuff works, and it's always good to have another qualified solderhead around, but you might want to ramp the attitude down just a little, since it's not winning you any new friends around here. But that's just me, and I can be safely ignored, so long as you don't break the rules, so consider it a suggestion.

I am sorry if my attitude offends anyone... but first off I never said my way was the only way; and secondly as someone new here how am I supposed to react to your first reply to my first post? I thought it was a little more than condescending in tone.

My suggestion to use the pa-2 came partly because I am familiar with the product and partly because I assume someone who is asking how to wire this guitar up in the first place probably has no shot of building the circuit needed himself. Something "off the shelf and readily available seems to me to be the ticket.

As far as my suggestion of concentric pots..... In the 7 basses and 2 guitars I presently own there's one on a fretless jazz for active bass and treble but that's it. I don't like them myself, but given the choice of using those or making extra holes in the top of a nice axe (I'm guessing the beast in question is a labor of love) I would use them at least until I decided I needed something else. It's a lot easier to drill a hole through a top than it is to hide an unwanted one.

I am not here to break yours or anyone elses balls, but I thought the beauty of this type of forum was the exchange of ideas....

My "delusions of grandeur" nonwithstanding; I think we have differing points of view and rather than banging heads we can probably provide a number of good opinions on the topics we respond to.

Perhaps we can all provide answers without snide comments or smugness and help each other as well as anyone else here out with ideas...

I

[lovekraft]

OK, sorry if I sounded condescending - I didn't mean to imply that you were stupid or anything of the sort, I simply meant that you were wrong when you told crafty most emphatically

...read my reply again... you need 2 pa-2's...

Now it's obvious that you truly believed that, but that don't make it so, and continuing to support an indefensible position makes you a target for a certain amount of good-natured smugness. Of course, if it was my very first post in this thread that rankled you, I make no apologies for it - the truth may not be popular, but that doesn't make it any less true.

Look, I have no evil agenda here, nor do I have any interest in making you look any sillier than you do all by yourself, but I've been doing this for a long time, and advising anybody that they need an extra fairly expensive preamp is gonna tend to make me holler, "Whoah!" If you consider that snide or condescending, that's your privilege. Welcome to the forum - your opinions are always welcome here, but you really can't expect us to agree with all of them, or hold them sacrosanct simply because you do - that also is inherent in any exchange of ideas.

OK, this is getting silly, so I'm through, unless somebody has on-topic questions. We'll simply have to agree to disagree, I reckon! This is your chance to get in the last word - just please don't quote this entire message in doing so.

[Hamer Bass Head]

I'm not going to argue with you, apparently I didn't adequately describe what I had in mind in my first post.

My reasoning for having 2 pa-2's (or whatever buffer/preamp you build or decide to use in it's place) was to allow a standard 4 knob layout; similar to a les paul or something along that line. The emg pickups require 25k pots. so on the active neck you would have 2 volumes and 2 tones..... Now in order to get around adding 4 more pots for the same functionality on the passive neck, I suggested using 4 25k ganged pots like emg provides for panning. If you remove the little wire jumper from the top to the bottom sections of the pots, it leaves you with 2 ganged volume controls if you wire them correctly. That leaves changing the impedance of the passive pickups. That's where the pa-2's or whatever you use in their place comes in. If you use a switch after a single pa-2 you won't be able to have the separate volume and tone controls for each pickup on the passive side. In retrospect I now realize that the 3 toggles would probably be a good idea anyway, as guitarists like to flip the switch and go while my bass-sided mind doesn't mind using the volume controls to alter my pickup selection. But I would wire the first switch to select between the passives (using the output of the corresponding half of the ganged tone controls and then repeat with the other half to the pickup selector for the active pickups. Adding the third switch from the outputs of the first two allows selection of either active neck, passive neck or both.

OK you might be able to rig something cheaper or maybe something completely different but I fail to see how it could be done without a whole lot more controls or losing the volume/tone control functionality for each pickup. Oh btw...I was reading the whole thread from the beginning and realized the guy wants another pa-2 on the emg side for a booster....maybe he can get a volume discount?