HEEELLPP!!! Wiring EMG pups w/ Aguilar Preamp

[stix_clgi]

Hey guys...I know, you're like "not ANOTHER idiot!!" Sorry....

So I've been trying to rewire my OBP-3 pre and add some EMG 45DC's. I've been at this since yesterday afternoon ( I was up till 4am!!) and I'm still trying to figure this out. The preamp used to have an always on passive tone control as well as a active/passive push/pull pot. I removed them and reconnected the proper wires (I think). BASSically the set up I'd like is a Vol, Blend, Mid pp, and stacked Bass/Treble. I've followed Aguilar's wiring diagram to a "T", I believe I've wired everything correctly...but I get no sound. Nothing. Nada. Zip. Zilch. Zero.... I get a staticy noise if I physically move the volume or blend pot which leads me to believe something is wired wrong, but I don't know

I've looked at a bunch of wiring diagrams, professional and hand drawn, and I can't seem to find the answer. My EMG 45DC's came with the quick-connect cable that is basically a coax cable (shield and white) and a red cable ( I'm assuming battery). I've wired both pups to the two middle posts on the blend pot, and I've soldered wires to connect the shields to the side of the pot (to ground them....that's what somebody's diagram said to do). I've got three wires, black from the obp-3, black from blend pot, another black from the volume pot, collectively soldered to the tip of the output jack. The negative battery wire is soldered to the sleeve, and the green from the obp-3 to the ring. Or at least what I think is the tip, ring, and sleeve. The Stacked B/T and Mid pots were already wired and were working before I took everything out. If anyone has this same setup and can provide a diagram I'd be most grateful, even if it was a Paint file....I'm ready to pull my hair out!!!!!!

Thanks in advance,

Stix

 

[mmbongo]

Make sure you're using the correct pots for the EMG's, you can't use standard pots made for passive pickups. You'll need 25k blend and volume pots.

Also keep in mind that Aguilar's diagram for wiring blend pots is not right. I followed the one at Stewmac which worked.

Bypass the blend pot and see if you can get one of the pickups working.

 

[stix_clgi]

The volume and blend pots are both 25k which is what EMG recommends. I'll have to find stewmac's diagram. Thanks for the response, I'll update the post when I try to bypass he blend.

 

[mmbongo]

Dats da one!

 

[Rano Bass]

Did you hook up the red wires from the pups to the red one that goes to the battery?

 

[stix_clgi]

Dats da one!

Okay, I have seen that one, and that's actually how the pot is wired....I'm going to try some more tomorrow, I have to study tonight, I'll be back though lol

Did you hook up the red wires from the pups to the red one that goes to the battery?

All of the red wires are hooked up together....I'm almost at the point of doing everything over again lol

 

[MultiScaleMale]

I have EMG 45Js hooked up to an OBP-3, but I have Vol / Vol instead of Vol / Blend.

 

[stix_clgi]

I have EMG 45Js hooked up to an OBP-3, but I have Vol / Vol instead of Vol / Blend.

Yeah, it definitely would have been much easier to install, but after dealing with that setup on my Spector I realize I just don't like it lol.

 

[stix_clgi]

Alright guys, finally got it. Turns out I had the blend pot wired backwards and upside down lol (following Aguilar's diagram). I used the diagram from stewmac.com (the same one posted above by mmbongo!) and it made a world of difference. So two new pots, quick-connect cables, barrel jack, and wiring diagrams later everything is working. Thanks to everyone for all of the help!! Pics in a few

 

[mmbongo]

Awesome! Glad you got it going!

I wish Aguilar would fix their dang diagrams.

 

[SGD Lutherie]

Dats da one!

Now you have to make sure you wire it the right way too. EMG usually uses linear taper blends, but if you are using M/N or A/B there's a wrong way and a right way to wire them. You have to measure them with a meter.

Here's an example using a 500K blend:

 

[SGD Lutherie]

Alright guys, finally got it. Turns out I had the blend pot wired backwards and upside down lol (following Aguilar's diagram).

That's what I was saying, and obviously you found it out first!

Blends don't all follow the same arrangement.

 

[stix_clgi]

Now you have to make sure you wire it the right way too. EMG usually uses linear taper blends, but if you are using M/N or A/B there's a wrong way and a right way to wire them. You have to measure them with a meter.

Here's an example using a 500K blend:

Okay, first, how do I measure the values you've indicated in the diagram? I don't have any type of tester, I'm assuming I'll need one of some sort right? Also, my blend pot is from AllParts.com; it's an audio taper pot, not a linear taper...and I'm noticing a problem (or a few...). First I guess I should explain a little better what I did now that I finally have sound an EQ control:

I basically wired a hybrid of EMG's quick-connect stuff and a hardwired Aguilar OBP-3 preamp. I removed the clips from the red (battery), black (ground), and white (signal/hot) cables that come with the pups, and hardwired them. The two whites are going to the center posts on the blend pot, the two pickup grounds are soldered together with the ground from the OBP-3, which are collectively soldered to the Sleeve of the output jack, per EMG and Aguilar's wiring diagram.

Now it get's a little hybrid-y. I wired the blend pot just like the diagram mmbongo and SGD posted with a ground (black) wire running from top left post to bottom right post, and vice versa with the signal wire (top right to bottom left). I used one of EMG's quick-connect cables to connect the signal and ground posts to EMG's quick-connect volume pot. The cable and pot basically combine the signal and ground into one cable that attaches to the pot with a little plug....it works beautifully and saved me a few soldering joints.

Everything else was wired to Aguilar's diagram. Blue wire from OBP-3 was soldered to the middle post joint on the bottom of the volume pot PCB. However, I didn't solder a ground from the volume pot to the other grounds at the output jack. The Treble/Bass stack and Mid pp were prewired and required nothing but installation from me.

So here's the problem(s):

1. I'm getting hum when I touch the knobs. It's occasional, but it happens, and it's loud. I'm thinking I need to connect a ground from the volume PCB to the other grounds at the output jack sleeve. What's weird is the hum goes away when I turn the volume pot all the way up...which leads me to the second problem.

2. The volume is not really acting like a volume pot. There's only a slight difference between when the pot is turned down and when it's turned up....basically my bass is always on, always loud lol.

3. I wired the blend backwards again LOL!!! Rotating forward selects the bridge pup, when it should be the neck pup....vice versa

4. The output signal causes my audio interface to clip, even when it's turned all the way down. I'm thinking the pups are too high...I've heard that they're very hot and can do that.

So I'm not completely out of the woods...but this has been a great, if long, learning experience, and any more opinions or advice is definitely appreciated. I feel like I'm doing something not a lot of people have talked about with using the cables and volume pot from EMG's quick-connect system. Maybe this will help someone else if they do a similar upgrade. Again, I appreciate any/all help!!

 

[SGD Lutherie]

Okay, first, how do I measure the values you've indicated in the diagram? I don't have any type of tester, I'm assuming I'll need one of some sort right? Also, my blend pot is from AllParts.com; it's an audio taper pot, not a linear taper...and I'm noticing a problem (or a few...).

You need an ohm meter. You can, and should, pick up a cheap multimeter at Radio Shack. They are handy for all kinds of things, such as checking batteries.

What you do is park the control at the center detent, and then measure from the center terminal to either outside terminal. You should dod this with the pot disconnected from the rest of the circuit.

You will see that between two of the terminals you have almost the full value of the pot. Between the center and the other one you have almost zero. The side with the larger resistance goes to ground, and the side that's almost zero goes to hot. Each deck is opposite. This way when you are at the center, you have the pickups full on.

Blends are never audio (A) taper. They are usually M/N, which is two linear tapers that end half way and go in opposite directions.

Everything else was wired to Aguilar's diagram. Blue wire from OBP-3 was soldered to the middle post joint on the bottom of the volume pot PCB. However, I didn't solder a ground from the volume pot to the other grounds at the output jack. The Treble/Bass stack and Mid pp were prewired and required nothing but installation from me.

So here's the problem(s):

1. I'm getting hum when I touch the knobs. It's occasional, but it happens, and it's loud. I'm thinking I need to connect a ground from the volume PCB to the other grounds at the output jack sleeve. What's weird is the hum goes away when I turn the volume pot all the way up...which leads me to the second problem.

The body of the pot needs to be grounded. When you turn the pot park way down you are putting series resistance between the pickup and the output. This can sometimes cause a little hum if you don't have adequate grounds and shielding.

So first connect the pot to ground, because it sounds like it's not. That should also ground the body of the pot. Putting some copper shielding under the pots, and grounding that will help with noise.

2. The volume is not really acting like a volume pot. There's only a slight difference between when the pot is turned down and when it's turned up....basically my bass is always on, always loud lol.

Your pot is not grounded. Make sure all the grounds on all the pots connect to ground.

3. I wired the blend backwards again LOL!!! Rotating forward selects the bridge pup, when it should be the neck pup....vice versa

Just swap the where the two pickups connect. I've seen them wired both ways. I do clockwise for bridge pickup.

4. The output signal causes my audio interface to clip, even when it's turned all the way down. I'm thinking the pups are too high...I've heard that they're very hot and can do that.

You mean a computer audio interface? It's probably not made for a signal like that. Just turn the volume down a little.

So I'm not completely out of the woods...but this has been a great, if long, learning experience, and any more opinions or advice is definitely appreciated. I feel like I'm doing something not a lot of people have talked about with using the cables and volume pot from EMG's quick-connect system. Maybe this will help someone else if they do a similar upgrade. Again, I appreciate any/all help!!

 

[stix_clgi]

You need an ohm meter. You can, and should, pick up a cheap multimeter at Radio Shack. They are handy for all kinds of things, such as checking batteries.

What you do is park the control at the center detent, and then measure from the center terminal to either outside terminal. You should dod this with the pot disconnected from the rest of the circuit.

You will see that between two of the terminals you have almost the full value of the pot. Between the center and the other one you have almost zero. The side with the larger resistance goes to ground, and the side that's almost zero goes to hot. Each deck is opposite. This way when you are at the center, you have the pickups full on.

Blends are never audio (A) taper. They are usually M/N, which is two linear tapers that end half way and go in opposite directions.

The body of the pot needs to be grounded. When you turn the pot park way down you are putting series resistance between the pickup and the output. This can sometimes cause a little hum if you don't have adequate grounds and shielding.

So first connect the pot to ground, because it sounds like it's not. That should also ground the body of the pot. Putting some copper shielding under the pots, and grounding that will help with noise.




Your pot is not grounded. Make sure all the grounds on all the pots connect to ground.



Just swap the where the two pickups connect. I've seen them wired both ways. I do clockwise for bridge pickup.



You mean a computer audio interface? It's probably not made for a signal like that. Just turn the volume down a little.

First, thank you for the wealth of information you've been providing SGD. I'm going to pick up a multimeter today while I'm out for future use.

I have a Presonus AudioBox that has hi-z inputs designed for guitars....I think the pickups are just really hot, plus I was having the grounding issue when I was playing through it,

I actually fixed the problem not too long after I made my last post. It seems that, as you mentioned, grounding the volume pot solved just about everything. I simply soldered a wire from one of the ground posts on the PCB to the ground network that is soldered to the output sleeve. No more hum and the volume works properly.

I actually decided to leave the blend knob as is...I am afraid to move it after all the time I spent cutting, stripping, and threading wires lol. I'm a novice at soldering, I don't want those joints to move AT ALL lol!!

So all in all, it "seems," again, that everything is working. We'll see after a day lol.

Thanks to everyone, especially SGD and MMBongo....I have another project I want to try now that I'm getting more experience. I'm gonna swap the Tonepump from my Spector Legend into my Schecter Stiletto Studio. I'm then going to throw another Aguilar OBP-3 into the Legend....it should be much easier for me this time lol!

 

[Juan fretlessbass]

Hi all,

I have a similar problem with obp1, Los potentiometers vol., Bass and treble are 25k and my capsule is a emg dc40. and no sound nothing. I discovered recently something strange when I connect the input jack half sounds low but very weak and distortion, when I connect the plug to complete this does not sound jack. Now I just try another jack stereo and has not been solved so I've connected diagrams according aguilar. PLEASE HELP

 

[Juan fretlessbass]

Hi all,

I have a similar problem with obp1, Los potentiometers vol., Bass and treble are 25k and my capsule is a emg dc40. and no sound nothing. I discovered recently something strange when I connect the input jack half sounds low but very weak and distortion, when I connect the plug to complete this does not sound jack. Now I just try another jack stereo and has not been solved so I've connected diagrams according aguilar. PLEASE HELP

 

[JustForSport]

Check the input jack wiring again- be sure of correct terminals.
Check to see that the jack is connecting the ground when the plug is in.
If nothing yet, run a jumper from the vol pot straight to the jack 'tip' connection.
Be sure you have a 'known' hot' battery.
Be sure the 'red' is also connected to the 'red' on the pickups,
and the grounds are all connected.
Report back after checking these things.

 

[Juan fretlessbass]

Check the input jack wiring again- be sure of correct terminals.
Check to see that the jack is connecting the ground when the plug is in.
If nothing yet, run a jumper from the vol pot straight to the jack 'tip' connection.
Be sure you have a 'known' hot' battery.
Be sure the 'red' is also connected to the 'red' on the pickups,
and the grounds are all connected.
Report back after checking these things.

Thanks the problem was solved. the jack was bad soldier

 

[Dr_Quinzel]

I've got a problem with EMG 45 DC and Aguilar OBP-3 SK/PP, wired according to Aguilar's diagram, vol/vol 25k pots, sound is distorted all the time, especially when playing lower strings; output is just too hot. Running 9V btw.