#1
I singled you 3 out because you've helped me before with my electrical shortcomings, and I pray that will do so again. Anyone with electronics knowledge please weigh in, this one's kinda weird, for me anyways, and I could use your help.

I'll bake you e-cookies in return, I promise


I'm thinking up a bit of a weird harness for my next build, and here's the plan:

EMG 89 and 81 TW ( basically just coil splittable versions of the 81 and 85 humbuckers ) set to coil split on push pull pots, and I'll be using a 3 way toggle. I want to also run them at 18 volts, switchable to 9 volts via a mini toggle, as well as including the EMG PA-2 boost and an ARTEC MT3 3 band active EQ circuit.

Here's my question: how do I run all the power? I understand the EMG + boost circuit, but what about the EQ circuit too? Should I just solder everything in the circuit to the battery clip at one place like I have drawn here, or should I be running different items to different clips or something like that? The ARTEC circuit can handle 22v, and of course the EMG stuff is able to deal with 27v, so running everything at 18v is what I want to do.

Here is a schematic of what I have going on in my head, let me know if you think it will work, and if it does work, would you guys would do it any differently? I have the signal running from the switch to the EQ circuit to the PA2 to the Jack. If it doesn't work, what will I need to change to make it work? Note that I'm running star grounding here, as apparently that's the way to go. Also, I haven't drawn in the coil splitting pots as I'm not sure just how they work with EMG's yet. Obviously this harness is going to be wack, so I'm prepared to take some flack in that department.




Also, I got my ideas from these three diagrams. Some of the links take you to directory pages, and they won't go deeper than that so you'll have to click or scroll a few times to find stuff:

ARTEC MT3 Equalizer Circuit

http://emgpickups.com/downloads/wiringdiagrams/EMG-PA2.pdf">EMG-PA2 Boost

9v-18v mini switch


Thanks alot guys!
#2
Well, on power, one set of batteries is definately best, it makes it easier to design your circuit, and you don't have to worry about figuring out which battery it is that's died. If you're doing that, it's easiest then to connect all the power lines to one place, so you're less likely to screw up a power connection.

Other than that, well, my electronics isn't so hot, but that's how i would've designed a circuit to do what you're doing.
#3
Ok cool, and thanks so much for your input! One other Q: the EQ circuit doesn't actually have a ground, I just kinda drew that in there. I should ground it somehow though, right? It's all low impedance so it's not going to be especially noisy ( unless it's a really crappy unit, and it might be :P: ) so it might not be that bad without it, but I should definitely figure some way of grounding that bad boy, right?
#4
EMG's installation instructions say when installing EMG Active Pickups, DO NOT connect the bridge ground wire. This wire is usually soldered to a volume or tone control casing and goes to the bridge. This wire grounds the strings and uses them and your body as a shield against hum and buzz. It also creates a shock hazard. EMG Pickups are shielded internally and DO NOT require string grounding. This greatly reduces the possibility of reverse polarity shock from microphones and other equipment.

The 81TW and 89 also have more wires than your diagram shows to allow the coil splitting. And the pots in your diagram are regular not push/pull pots.
Here's a link.
http://www.emginc.com/displayproducts.asp?section=Guitar&categoryid=6&catalogid=190
The EMG PA-2 boost wiring looks OK.

I don't know about the ARTEC MT3 3 band active EQ circuit. I've never messed with one of those before.
Last edited by zakkwyldefan79 at Jan 13, 2009,
#6
^You'ld think they'd just remove the damn wire if it was unnecessary...


Looks like the MT3 doesn't need any grounding either tho, and it probably isn't possible to ground it, you'ld have to crack open the case and start fiddling with the pcb.
#7
Quote by zakkwyldefan79
EMG's installation instructions say when installing EMG Active Pickups, DO NOT connect the bridge ground wire. This wire is usually soldered to a volume or tone control casing and goes to the bridge. This wire grounds the strings and uses themand your body as a shield against hum and buzz. It also creates a shock hazard. EMG Pickups are shielded internally and DO NOT require string grounding. This greatly reduces the possibility of reverse polarity shock from microphones and other equipment.

The 81TW and 89 also have more wires than your diagram shows to allow the coil splitting. And the pots in your diagram are regular not push/pull pots.
Here's a link.
http://www.emginc.com/displayproducts.asp?section=Guitar&categoryid=6&catalogid=190
The EMG PA-2 boost wiring looks OK.

I don't know about the ARTEC MT3 3 band active EQ circuit. I've never messed with one of those before.



Thanks for the tip on the grounding man! I haven't included the push pull action from the EMGs in this diagram cause that's not something I'm worried about, I just wanted some info on the power.

What should I do to ground all the other stuff though? The EQ circuit runs on 3 500k pots, and the PA2 is going to need grounding for sure. That's a full guitar's worth of stuff that needs grounding right there, so do I run a ground for THAT stuff from the bridge and then send the EMG ground somewhere else? Where should I send it? In all the diagrams it looks like they just send the EMG ground straight to the jack, but that won't work for grounding all that other stuff, will it?
#8
Quote by lumberjack
Thanks for the tip on the grounding man! I haven't included the push pull action from the EMGs in this diagram cause that's not something I'm worried about, I just wanted some info on the power.

What should I do to ground all the other stuff though? The EQ circuit runs on 3 500k pots, and the PA2 is going to need grounding for sure. That's a full guitar's worth of stuff that needs grounding right there, so do I run a ground for THAT stuff from the bridge and then send the EMG ground somewhere else? Where should I send it? In all the diagrams it looks like they just send the EMG ground straight to the jack, but that won't work for grounding all that other stuff, will it?

I guess you would ground the other things like normal but not the bridge. I'm not 100% sure though. Let's wait and see what Invader Jim thinks and maybe SomeoneYouKnew will help too.
#9
I'd be wary of throwing a cheap EQ in there with EMGs, just in case it flavours your tone completely, and turns it to mush. .. and even so, shouldn't you put the EQ last?
#10
Id just leave the bridge ground wire connected.

EMGs just dont need that connection. If you have it the only drawback youll have is the shock risk, exactly the same shock risk you'd have with a passive gutar.

I had for a while my active circuit grounded to the bridge and Im still alive
#11
I've gotten to where if I see my name in a thread title, I get a little scared...

Everything gets grounded to the ring terminal. Ott, everything else has been said, I think.
#12
Quote by -MintSauce-
I'd be wary of throwing a cheap EQ in there with EMGs, just in case it flavours your tone completely, and turns it to mush. .. and even so, shouldn't you put the EQ last?



The EQ circuit is as cut/boost deal, so in the center detend the pots are completely inactive. Granted, you may be right in assuming they will still color the sound even when they are off. I really didn't want to use the ARTEC because it's cheap, but there is literally no other option for 3 band on-board EQ circuits based on pots that will accept 18v, so here is my plan:

1. Wire up the guitar without the EQ, see how it sounds.
2. Wire in the EQ and see if it's good or not. Obviously I wouldn't drill holes until I decided to keep it or not

I don't really have any other choice, other than giving up on the idea of an on-board 3 band EQ, and I'm not giving up until I try this circuit. I really want one for a variety of practical reasons, but I'm not going to be using the thing like a 3 band EQ on an amp; I'll dial in my amps as close as I can get them, and then "season to taste" with the on-board EQ, that's the whole idea. Some amps just won't go where you want them to go, e.g., always sounding dark even if the treble is maxed, always sounding too middy even though you have cut the mids out, not sounding middy enough even though you've got it dimed, etc. etc. So, with the coil-splitting EMG's running at 9 or 18volts with that boost and EQ circuit, I could take my guitar to most any amp and have an extremely flexible and great sounding set up without having to lug multiple guitars and a pile of effects around. It would be uber.


I would love for you guys to suggest a high quality 3 band EQ other than the ARTEC, and I even made a thread for that purpose, but I just can't find anything else. The only other things out there are :

a-- 2 band
b-- Fishman style
c-- No name, therefor I can't figure out their voltage specs (needs to accept 18v).

If you guys know of anyone who builds this kind of stuff give me a shout. Hopefully one day I'll be able to build it for myself!
#13
You should be fine with an Aguilar, Delano, or Glockenklang bass preamps. The frequency bands on bass preamps are pretty close to the bands on the MT3.
#14
buy a EQ pedal, and throw it in the guitar?
Just call me Bobby
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#15
^ good call, onboard!

OH,

but will that run on 18V worth of batteries?

I know they take 9, but it could be possible to have 18V as one position, JUST 9V on the second, and 9V w/EQ on the third, know what I mean?
------

Shwiggity.
#16
Could always design a voltage divider that will give you only 9V into the EQ, and use a different EQ?

Edit: Bah, ignore me, it's still too early in the morning. Obv, with the 9/18V switch, my suggestion is completely and utterly useless
Last edited by Mad_BOB at Jan 14, 2009,
#17
Quote by Mad_BOB
Could always design a voltage divider that will give you only 9V into the EQ, and use a different EQ?

Edit: Bah, ignore me, it's still too early in the morning. Obv, with the 9/18V switch, my suggestion is completely and utterly useless



Not really, because as it stands I have the switch changing the voltages for the entire circuit, so your suggestion would work.

BUT all this conjecture about a different EQ will not be useful until I've decided whether or not the ARTEC circuit is any good. I've got one on order because I didn't consider using bass EQ's or pedal guts at the time, so if it sucks really bad then I'll try looking into those options...