EMG Solderless + 18V Mod + Low-Battery Indicator - I'm Lost

[alexreinhold]

Lately, I have been biting off a bit more than I can chew (if you have followed a couple of my other posts). But I guess that's how we learn. Anyway...

I am currently doing an EMG 81/60 installation that should look like this on the surface:

As you can see, this standard diagram assumes EMG's solderless system with a "buss" in the middle which acts as an intersection to all wires. However, here is what I want to achieve:

- 2 Pickups
- 3-way switch
- Master Volume
- 2 batteries (2x 9V),
- Push/Pull Master Tone (Push: 9V, Pull 18V) wired in Series Parallel
- Low battery indicator

Taking this step-by-step, the whole thing should look like this:

The following wiring diagram should work from physical perspective:

Now, given the EMG solderless system, I am facing a few problems I did not account for:

1. the EMG push/pull pot is designed for the solderless system:

2. the Warmoth double battery box (which I am using) is NOT designed for the EMG solderless system

3. The Low-Battery Indicator (see pictures above), is NOT designed for the EMG solderless system

Problem: I have no clue how to solder to a solderless system.

So, I am thinking I have to go for a hybrid between solderless and soldered. Here is what I think:

General Remarks:
- keep the EMG solderless volume pot
- toss the complex solderless EMG push/pull pot and get a solder push/pull from Fishman or Allparts (25k of course).

For the pickups:
- keep connection to switch through buss as is
- cut red wire and connect to Fishman/Allparts push pull

For the volume pot:
- keep connection to switch through buss as is
- keep EMG wire that is supposed to go to the tone control solderless, cut it and connect the white end (i/o) to the Fishman/Allparts push pull. Tape off the black end (ground)

General Questions:
- do i need to any grounding on my 3-way blade switch (see above, not using toggle but blade)?
- will the solderless Fishman/Allparts push/pull need a cap?

What do you think?

 

[stratamania]

One thing that may help you...

Regarding battery boxes. You need to splice the solderless part minus the battery clip to the battery box leads... obviously also make sure you have routed any wires through holes in the body where needed before joining.

https://www.unofficialwarmoth.com/index.php?topic=30781.msg434209#msg434209

Why not just do the 18V mod which will give the 81 and 60 headroom and dispense with the push pull and use a VLPF for the tone pot instead?

 

[drewfx]

If you are wanting to switch between 9 and 18 volts, what are you expecting to achieve?

 

[alexreinhold]

One thing that may help you...

Regarding battery boxes. You need to splice the solderless part minus the battery clip to the battery box leads... obviously also make sure you have routed any wires through holes in the body where needed before joining.

https://www.unofficialwarmoth.com/index.php?topic=30781.msg434209#msg434209

OK, that makes sense. Doesn't necessarily make things easier but well - getting used to that

Why not just do the 18V mod which will give the 81 and 60 headroom and dispense with the push pull and use a VLPF for the tone pot instead?

not a bad idea but I'm not sure I'm interested in passive/active split. I want the guitar to be as straight-forward as possible. To be honest, the 18V vs 9V split is also not super important to me - I just thought it's a nice little gimmick - given the (mostly irrational?) hype on 18V mods with EMGs since the 80s.

If you are wanting to switch between 9 and 18 volts, what are you expecting to achieve?

https://www.electricherald.com/18v-mod-active-pickups/

 

[stratamania]

Why not just do the 18V mod which will give the 81 and 60 headroom and dispense with the push pull and use a VLPF for the tone pot instead?

not a bad idea but I'm not sure I'm interested in passive/active split. I want the guitar to be as straight-forward as possible. To be honest, the 18V vs 9V split is also not super important to me - I just thought it's a nice little gimmick - given the (mostly irrational?) hype on 18V mods with EMGs since the 80s.

There is not a passive/active split.

You would have EMG pickups powered by a 18V Mod for extra headroom and no switching to 9V. A VLPF is an active tone control designed for EMG-X series or you could use the RPC to give the EMG HBs some more tonal variety.

https://www.emgpickups.com/guitar/guitar-accessories/rpc.html

 

[drewfx]

If you are wanting to switch between 9 and 18 volts, what are you expecting to achieve?

https://www.electricherald.com/18v-mod-active-pickups/

The point is really that if you aren't running out of headroom at 9V it shouldn't make any difference (and running out of headroom is much more common on basses than guitars). Beware of people on the internet who don't actually understand what "headroom" means reporting hearing things that have nothing to do with headroom.

You also generally don't want to run 2 batteries in series with different amounts of battery capacity left anyway, which would happen if you ran at 9V a significant amount of time.

 

[TBurst Std]

If you are wanting to switch between 9 and 18 volts, what are you expecting to achieve?

https://www.electricherald.com/18v-mod-active-pickups/

The point is really that if you aren't running out of headroom at 9V it shouldn't make any difference (and running out of headroom is much more common on basses than guitars). Beware of people on the internet who don't actually understand what "headroom" means reporting hearing things that have nothing to do with headroom.

You also generally don't want to run 2 batteries in series with different amounts of battery capacity left anyway, which would happen if you ran at 9V a significant amount of time.

Very true.

 

[alexreinhold]

The point is really that if you aren't running out of headroom at 9V it shouldn't make any difference (and running out of headroom is much more common on basses than guitars). Beware of people on the internet who don't actually understand what "headroom" means reporting hearing things that have nothing to do with headroom.

You also generally don't want to run 2 batteries in series with different amounts of battery capacity left anyway, which would happen if you ran at 9V a significant amount of time.

So are you saying that a) the 18V mod doesn't really make sense. And b) that I should decide between going either series (18V) or parallel (9V)?

But, in theory, is there even a way to do a push/pull setup where I either run in series or in parallel (i.e. battery lives will be the same for both at all times)?

 

[stratamania]

What I call an "18V mod" is using two 9V batteries in series, which may give more "headroom" to the EMG pickups which is probably worth doing for the humbucker combo you have. It won't have any negative effect but  I don't see any point in switching between 9V and 18V.  All of that said my EMGs run fine on a single 9V battery.

 

[alexreinhold]

What I call an "18V mod" is using two 9V batteries in series, which may give more "headroom" to the EMG pickups which is probably worth doing for the humbucker combo you have. It won't have any negative effect but  I don't see any point in switching between 9V and 18V.  All of that said my EMGs run fine on a single 9V battery.

OK, you are right. I am also starting to feel like I want to simplify things - i.e. let go of the 18V mod and the push/pull and go 9V all the way. However, I still have the battery indicator (which I would like to add) + the double battery box from Warmoth.

Following the EMG solderless wiring diagram I pasted in the original post, how do I go about connecting

a) two batteries in parallel that are not in the solderless system
b) the low battery indicator which works like so:

 

[alexreinhold]

Yeah, the more I think about it, the more I'm fine to get rid of the push pull and run the two batteries in parallel at 9V at all times. Now, here's where I'm stuck:

 

[stratamania]

Break it down a little.

For 18V non switchable. See below for parallel 9V.

1. Rout the leads from the battery boxes to the control cavity and make sure you know which lead is which.
2. Create a series link by joining the red wire from battery box 1 to the black wire of battery box 2 and insulate.
3. Black negative output of battery box 1 join it to the solderless connector for the output jack by clipping off the battery clip - see the link to the post I mentioned earlier.
4. red output wire from battery box 2 join it to the solderless connector for the red solderless connector which connects to the battery bus by clipping off the battery clip and insulate - see the link to the post I mentioned earlier.

That completes the 18v wiring but does not include the battery indicator.

To add the battery indicator add a black wire between the sleeve of the output jack and the battery indicator - terminal.

For the red wire from the positive terminal of the battery indicator there are two possibilities.

a. If you have a spare red solderless connector connect that to the EMG battery bus and cut the other end off and solder it to the + of the battery indicator.
b. An alternate to a. above is to use a variation of 4 above, but when you join the wires graft in a third wire to use to connect to the + of the battery indicator.

For parallel 9V

1. Rout the leads from the battery boxes to the control cavity and make sure you know which lead is which. (not as critical as for the series wiring)
2. no series link required so omit this step.
3. Black negative outputs of both battery box 1 & 2 join them to the solderless connector for the output jack by clipping off the battery clip - see the link to the post I mentioned earlier.
4. red output wires from both battery box 1 & 2 join them to the solderless connector for the red solderless connector which connects to the battery bus by clipping off the battery clip and insulate - see the link to the post I mentioned earlier.

 

[alexreinhold]

Stratamania, thanks a lot - I think I got it. Can you confirm that these two wiring diagrams look correct?

18V

9V

 

[stratamania]

Yes they look to be correct. 

 

[alexreinhold]

Quick update: this is strange! Next to consulting you guys, I e-mailed EMG with the same questions. First of all, their customer service is remarkable - very patient and with a lot of attention to detail. But here's the thing - their in-house guitar tech says the following:

To be clear, you should never put two 9V batteries in parallel.  The definition of parallel is – positive terminals of both batteries share a common connection, and the negative terminals of both batteries share a common connection.  18V connections are always made in series  - the negative of one battery is connected to the positive of the other, so there’s a linear path between the two of them.

After I mentioned that forums and Sweetwater (https://www.sweetwater.com/sweetcare/articles/multiple-batteries-emg-pickups/) advocate a 9V parallel he re-emphasized:

Please, do not wire batteries in parallel, ever.  This can be a safety hazard, and I’ve heard multiple stories of people burning themselves touching a battery that was overheating because of being connected in this way.

I am very confused now (and sad that I don't understand the fundamentals of electrical engineering). In any case, he recommends to either go for the 18V mod or actually do the push/pull with the following wiring:

Would be keen to hear the experts' opinions.

 

[Sadie-f]

Ahh, yeah. I was going to reply to you to this effect, and then I thought about the primary battery parallel mode problem, decided maybe it doesn't apply to you.

Afaik, all battery types have inverse relationship between heat and internal resistance. This means if you draw significant load, whichever battery happens to draw more power heats up and draws still more power. That's a positive feedback loop that causes unequal discharge rates in parallel wired batteries. It's probably worse on batteries that both charge & discharge.

So I take it as basic that without some support wiring, which can be as simple a resistor network separating all the parallel units. A while back I posted a circuit for running any number of 9v as a pedal power supply using Schottky diodes (for low voltage drop) to eliminate uneven discharge, and isolate any possibility of a lower voltage battery being charged by a higher voltage unit.

And that problem is probably why you don't want to do || 9v. If you're using alkaline, they must never be in a charging situation. If, like me, you're using lithium rechargeable, a safe charging circuit is non-trivial, I didn't want to get into it.

Also, with the diodes, I can safely mix battery types.

 

[TonyFlyingSquirrel]

For guitar or bass, I would only use the standard 18v mod just to ensure you don’t get burnt or fry your pickups.

https://www.electricherald.com/wp-content/uploads/Active-Pickups-Standard-18v-Mod.jpg

 

[JohnnyHardtail]

I understand the risk of the temperature co-efficient of battery voltage. but I'm still not totally convinced this problem will occur with Alkaline batteries in practice especially because of their internal resistance.  Also I have a Logitec mouse that is designed with 2 x AA batteries connected in parrallel.  However I would take the warning seriously because guitars are made of wood.

 

[stratamania]

Also I have a Logitec mouse that is designed with 2 x AA batteries connected in parrallel. 

The key words there are it is designed to be connected in parallel. So in that case a single battery would not work too well.

@Alex, to simplify what is happening with series and parallel battery wiring.

Series, gives you the sum of the voltages added together 9V + 9V = 18V
With two parallel batteries you still have the same voltage but the current is increased which may be desirable in the case of the Logitech mouse designed for that but less so for EMGs as they have advised.

Having a switch to switch between 18V series or a single battery running in 9V as EMG suggested might  give a chance to see which set up you prefer. Though the only practical purpose I can think of is if you need to replace batteries and only have a single replacement available as you are about to play Madison Square Garden may have a benefit. Though the moral here is if you are using active pickups is to have spare batteries in the gig bag.

 

[alexreinhold]

Thanks for the explanations everyone - I get the difference between series and parallel at this point but I would still be a lot more happy if I actually understood the fundamental electrical engineering component better. A colleague of mine is a physicist who builds amplifiers himself - so I will let him crash-course me

Having a switch to switch between 18V series or a single battery running in 9V as EMG suggested might  give a chance to see which set up you prefer. Though the only practical purpose I can think of is if you need to replace batteries and only have a single replacement available as you are about to play Madison Square Garden may have a benefit. Though the moral here is if you are using active pickups is to have spare batteries in the gig bag.

@Stratamania I have 2 questions and 1 remark regarding that. Questions:
1. so the push/pull wiring diagram from EMG makes sense, you just don't see the practical purpose in it, right?
2. isn't there supposed to be an actual sonic difference between 18V and 9V?

Remark: Madison Square Garden might be a stretch but I refuse to stop dreaming But in all seriousness, the guitar that I am building is supposed to be as metal as possible. And the beauty about metal is that we metalheads do take it seriously but also like to make fun of ourselves. One of the things that is right on the edge of being dead serious and total BS is the legendary 18V mod. And I thought it was a nice gimmick to be able to switch between the standard 9V (as the default) to 18V mod just because I can. Does that make sense?