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Fodera/EMG issue.

iandmcelroy

iandmcelroy

Apr 20, 2008
177
118
British Columbia, Canada
#1
Hey Talkbassers,

I have a Fodera that has some electronic buzzing -- There's a bit of history here so I'll do my best to explain everything.

When I first got the bass, from here, the bridge pickup in the original EMG PJ set sounded a little funny, and I got it checked out. Turns out something in the J-Pickup wasn't working anymore and I replaced the whole set with an EMG PJX set. Problem solved completely.

Now a year and a bit has gone by and I'm thinking that I'd like to change the tone, and I order a PJAX set to get a little closer to a vintage type of tone.

I put them in and noticed that there was a little bit of noise, but nothing too out of the ordinary. As soon as I hit the stage the next night there was quite an issue with buzzing under the lights. In fact, the buzz was louder than the actual bass -- It was not a fun gig. I can play the bass in pitch black, but as soon as any lights get turned on, everything goes downhill.

I went back to the EMG PJX set the next day and played another gig in the same room, with the same setup, under the same lights, same songs, and even at the same time of night. No problems.

The wiring diagram shows that everything is connected the same between the two sets, and there should be a little less output from the PJAX set. However, the PJAX set is way louder than the PJX set.

And here is the only reason I'm posting this. I love the sound of the PJAX set, and want them to work.

Is it possible that I just got a bad set?

Is there anything I might be overlooking when they were installed?

I took it to my local luthier and had him check everything out and everything was mostly perfect, except of a bit of a scratchy volume pot, when it came to the installation and wiring. There were no faults found in the pre-amp and nothing changed in the pre-amp/electronic side during the installation. It was just the solder-less pickup swap that EMG has used for years.

Could the volume pot be the real villain? (dun dun dun)

I emailed EMG and they didn't get back to me.

I'm stumped, EMG is usually flawless.

TL;DR

Here's a summary:
Fodera with PJ Set = Bad because they were broken.
Fodera with PJX Set = Good.
Fodera with PJAX Set = Bad?? How? Help??!!
Fodera with same PJX Set that was installed before = Good Again, but the tone isn't as good.

Thanks for your time.
 
#2
It does sound fishy, as EMG's are usually hum cancelling, but maybe to cop that old school vibe the PJAX set is a true single coil? I wouldn't think so, but that is what it sounds like. The other possibility is some sort of grounding issue with the way the new set is wired. If there is a shield as well as a ground try connecting both together, and then only the ground and leave the shield disconnected. One of those options might fix it. I doubt the volume pot is the culprit, since you only have the problem with the new pickups. The only way I see that being the culprit is if there is some drastic difference to the circuit for the PJAX and you have to use the pots they came with. That seems highly unlikely, though. I would try giving EMG a call, as usually that is better than email as far as response time.
 
#3
Thanks for the reply.

I'm going to add a bit more relish to this burger.

On the EMG PJX Set, the set the works with no buzz at all under lights, has a slight, very, very, very slight, static sound if I run my fingers over the pickups.

You can only hear it if the volume is at MAX, and even then it is still very quiet. Literally with the gain all the way up, and the output all the way up.

Thanks for your help.
 
#4
are the AX active or passive? if passive you'll need 250k pots instead of the 25k used for the active ones and you might need to wire back the ground from the bridge (EMG advise to NOT ground the bridge/strings for their ACTIVE pups).

M
 
#6
I am confused ... 1st I found one reference on the emg website about the pjax series and this was on the pricelist. I cant find specific info about these on the site. I did see a J bass set listed as a jax set so perhaps they are simply swapping 1 of the j pickups out in this set. Regardless it does appear to be a single coil pickup.

Stupid question. Are the Fodera EMG's "off the shelf" or designed for their basses? My suspicion is that Vinnie has these spec'd to work to his desires and preamp choices.

Thats a shame you are being forced to mod a $4000 bass man.. Will Fodera not help at all?
 
#7
As far as I know the EMG's that Fodera uses are the same ones that you can buy in any store. I haven't talked to Fodera yet for two reasons: The bass is out of warranty and I'm trying to get everything sorted out before calling. I bought the bass used and they've helped me before, but I try to make it a last resort because of how busy they are and how far away I am from them -- It can be hard to diagnose things over the phone. Secondly, it looks like it's a long weekend and everyone is away.

Whenever I have talked to Fodera the entire staff has gone above and beyond the call of duty to help me every time.

The PJAX Set is in EMG's catalogue, but not on their web page. It's the exact same set as the PJX Set, but with Alnico magnets, and probably something else that EMG is not telling us.

There are a few differences between them:

P-Pickup

Ceramic Magnet
Res. Freq. - 320khz
Out Noise - -106db

Alnico Magnet
Res Freq - 2.61khz
Out Noise - -101db

Jazz-Pickup

Ceramic Magnet
Res Freq - 4.05khz
Out Noise - -105db
Output Voltage - 8.00

Alnico Magnet
Res Freq - 3.48khz
Out Noise - -101db
Output Voltage - 6.50

Everything else is the basically the same.

EDIT: The P - Pickup is also buzzing the same amount as the Jazz. They also make the same buzz when they they are running together and separately.
 
#11
Your problem is not your bass, or the pickups, well at least not as in a malfunction. That noise value is -101 at 60hz for the AX vs -106 for the X. That is your problem. You lost 5db in your noise floor due to the less hot magnets in the AX. That is why you noticed the stage lights with the new set. There is not really anything you can do, as it being a Fodera, I am sure all of the shielding is adequate. There is absolutely no other difference. The plugs and three wire set up are all the same. The instructions are exactly the same. That noise spec and resonant freq are the only differences.
 
#12
Unfortunately, without seeing the instrument and playing it, this is a nearly impossible issue to properly diagnose. Sadly, with used instruments we have no idea what happened to them after they left the shop. We have seen some truly "amazing" modifications that have caused all kinds of problems. That said, it sounds like initially one of the EMG Pups went bad. This happens very, very rarely but it is not unheard of. As to what was going on the night that you were on stage, it sounds like a possible grounding issue.

The very best thing to do would be to send the bass back to the shop for a thorough diagnosis and fix. Yes, there are shipping and labor costs involved, but the bass will be perfect when you get it back.

Kindest regards,

Jason

winegamd said:
Your problem is not your bass, or the pickups, well at least not as in a malfunction. That noise value is -101 at 60hz for the AX vs -106 for the X. That is your problem. You lost 5db in your noise floor due to the less hot magnets in the AX. That is why you noticed the stage lights with the new set. There is not really anything you can do, as it being a Fodera, I am sure all of the shielding is adequate. There is absolutely no other difference. The plugs and three wire set up are all the same. The instructions are exactly the same. That noise spec and resonant freq are the only differences.
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