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No output from active pickups

Posted: Thu Jul 13, 2006 4:52 am
by delberthot
I have just wired up a new set of active PJ EMGs to one of my basses but I had to use a different jack to the one supplied as it is one of the long barrel type ones.

The problem is that I get sound from it when the cable is half way in but nothing when it is all the way in. I know I have got a cable wired up the wrong way but can't figure out which one.

Does anyone have any ideas?

Thanks in advance

Posted: Thu Jul 13, 2006 5:12 am
by shinynewtoy
Sounds like you might have used a stereo jack instead of mono.

Posted: Thu Jul 13, 2006 5:25 am
by delberthot
I thought that it was a stereo jack that you used for active pickups?

I have a cable coming from the grounded lug on the tone pot, one coming from the middle lug of the volume pot and the a third for the battery. So that's 3 connections.

Do mono jacks not only have 2 places that you can connect cable to?

Posted: Thu Jul 13, 2006 5:51 am
by shinynewtoy
Actives may be a different beast, but unless you want to run your bass in stereo you have to have a mono output. I'm going to make a semi- educated guess (being a passive pickup kinda guy) that a mono jack would work if the tone and volume pots were wired as a chain, leaving the other lug for the battery.

Maybe someone more well-versed in active pickups has more to offer... but I'm thinking the stereo jack is the culprit. I did find this for you on EMG's site...

My pickups do not work unless the cord is plugged halfway in. Did I wire them wrong?
Probably not, but you should check the orientation on the Quick-Connect cables. You may have the connectors on upside down.

Posted: Thu Jul 13, 2006 10:06 am
by delberthot
I had a good look at the EMG website and found this:

"The jack I have in my guitar has a much longer shaft than the one supplied with the EMG pickup. Can I use the one in the guitar?

That depends on what kind of jack you have in your guitar. Active pickups require a stereo jack to turn the battery off when the guitar is unplugged. A stereo jack has 3 solder lugs. Many of the Ibanez guitars come stock with a stereo long shafted jack. There is one lug not used with passive pickups and that is where you will connect the battery black wire. If your jack has only 2 solder lugs it is mono and you will need to replace it. We recommend a Switchcraft p/n 152B. You should be able to find it at any decent electronics parts house. If not, you can order it from us. "

I have an older set of EMGs that don't have the quick connect cable and have wired them according to the schematic. the only thing I think I could've done is wire the jack wrongly

Thanks for looking for me though :-D

Posted: Thu Jul 13, 2006 10:20 am
by shinynewtoy
WHOOPS!!!!!!!!!

Shows how much I know... Image

Posted: Thu Jul 13, 2006 10:55 am
by beatlefreak
It sounds like if you're supposed to use a stereo jack, then you possibly have it wired wrong.

Since you'll be plugging a mono plug (the cord to your amp) into a stereo jack, I would guess the jack needs to be wired as follows:

1. The wire from the volume pot needs to go to the "tip" of the jack (The last one to make contact when the plug is inserted.)
2. The wire from the tone pot ground needs to be connected to the "ring" of the jack (The first one to make contact when the plug is inserted.)
3. The wire from the battery needs to be connected to the "intermediate" of the jack (The one in between tip and ring).

Connected this way, since the intermediate and ring will be common when a mono plug is inserted into the jack, this will connect the negative of the battery to ground, completing the circuit.

You may need an ohmmeter to determine which lug on the jack is tip, ring, and intermediate, or you may be able to visually see it.

Hope this helps.

Posted: Thu Jul 13, 2006 11:17 am
by delberthot
Thanks - I'll give it a try

Posted: Fri Jul 28, 2006 9:32 am
by delberthot
I didn't have time to have another go at this again until now. It seems that the battery goes to the ring and the other 2 fight over the other 2 connections.

Just in time for tomorrow's gig

Posted: Fri Jul 28, 2006 10:30 am
by doctorwho
Derek, I didn't see this until now; maybe this diagram at Stew-Mac will help:

http://www.stewmac.com/wiring101/active_electronics.html

Bartolini also has a bunch of diagrams available:

http://www.bartolini.net/support/install_instructions.htm

In these examples, a stereo jack is used.