Strange EMG P pickup problem (distortion fixed itsself?)

PilbaraBass · #1 05-19-2008, 09:05 PM

I recently regained posession of my first bass a 1991 precision parts bass.

When building the bass, I fitted it with an EMG active P...
When I was playing it back in America, I noticed that if I played the E or A string too hard, it had a terrible distortion on it.

Upon bringing it to Australia, and putting an entirely different battery in it, the same problem existed.

Strangely enough, after I finished setting it up and playing it a bit (a good 1/2 hour playing session) the problem is GONE.

i CAN get distortion, but I really have to hammer on the strings now...NOTHING like before...

any ideas on what could be going on here?

Bassamatic · #2 05-21-2008, 08:19 AM

I think it was a bad or dirty switch or pot, acting a bit like a diode when hit with a larger voltage. After a bit of usage it cleaned itself!

PilbaraBass · #3 06-23-2008, 02:51 PM

distortion is still there...

I cleaned the pots last night with contact cleaner...they're not scratchy in the slightest now...

I'm finding that some settings on my Zoom B2.1u have loads of distortion and others don't.

not a preamp loading issue, since this is constant into the zoom.

It could be, however, that some frequencies are just driving the input too hard (dependent upon setting).

I'll get a few resistors and a pot and make an attenuation pad and see how that goes.

PilbaraBass · #4 06-24-2008, 03:21 AM

i'm still interested in anyone who's completely solved this problem and how they did it...

I know replacing the pickup is an option...so don't suggest that...Actually, I am considering a kent armstrong soapbar, instead (I loved this pickup when I had my wishbass).

PilbaraBass · #5 06-25-2008, 08:09 PM

bumpage...

anyone sharing similar problems with EMG actives?

PilbaraBass · #6 06-27-2008, 03:37 AM

I'm bumpin' again...

DavidRavenMoon · #7 06-27-2008, 05:26 PM

Does it still distort if you turn the volume on the bass down? Have you tried lowering the pickup?

Running it on 18V might help if it's coming from the pickup itself. It might just be too hot for your gear... sounds odd from an EMG, but I had that happen with one of my active pickups.

Check the output jack and also the wire going to the battery. I had a lot of distortion once from a bass with EMG's and the problem was the output jack wasn't switching the battery on right. I had to push the jack al the way in. I replaced the jack and everything was fine.

PilbaraBass · #8 06-27-2008, 06:41 PM

Quote:

Originally Posted by DavidRavenMoon

Does it still distort if you turn the volume on the bass down? Have you tried lowering the pickup?

Running it on 18V might help if it's coming from the pickup itself. It might just be too hot for your gear... sounds odd from an EMG, but I had that happen with one of my active pickups.

Check the output jack and also the wire going to the battery. I had a lot of distortion once from a bass with EMG's and the problem was the output jack wasn't switching the battery on right. I had to push the jack al the way in. I replaced the jack and everything was fine.

thanks for the response, David.

I don't think it's too hot for my gear as my Squier Active sounds louder. Interestingly, the distortion seems to manifest itsself when you dig in on the strings...sounds like the preamp in the pickup may actually begetting clipped. 18V may help, and I've considered this.

Right now the battery is just tucked away in the control cavity of the P-bass. I really didn't want to go for any more routing...but I can easily enough test 18V to see if that does sort the problem adequately. Otherwise, I just may go passive...

One final interesting thing to muddy the issue is that depending on my settings on my B2.1u I get more or less distortion...not an issue with any of 4 other basses I've tried in the zoom with similar (or identical) presets.

DavidRavenMoon · #9 06-27-2008, 06:58 PM

Before you go and rout the bass, try attaching a second battery.. just leave the pick guard hanging. It might be a bad preamp in the pickup, but it's odd it only affects the one half, since they both use the same preamp.

I'd check over the wiring.. something might be shorted out having to do with the battery.

I've never had these issues using EMG's, so I think the pickup might be bad... or something is amiss with the wiring.

PilbaraBass · #10 06-27-2008, 07:30 PM

Quote:

Originally Posted by DavidRavenMoon

Before you go and rout the bass, try attaching a second battery.. just leave the pick guard hanging. It might be a bad preamp in the pickup, but it's odd it only affects the one half, since they both use the same preamp.

I'd check over the wiring.. something might be shorted out having to do with the battery.

I've never had these issues using EMG's, so I think the pickup might be bad... or something is amiss with the wiring.

yep...I've got a pack of 9V battery connectors, I'll just fashion an 18V to 9V adaptor from 3 of them and plug it right in (tonight maybe)...It's a P-bass with everything mounted to the PG so looking at the wiring is very easy and nothing out of the ordinary is apparent...