Question about 1 and 2 pickups on a bass

Rocker

Does the second pickup on (say) a PJ bass affect the purity of the sound of the selected pickup?  I want to add that the second pickup has it's volume control set at zero.  Would/could the magnetic field of the second pickup affect the string vibrations and hence alter, even if slightly, the sound.

I tried two basses today, both lowish price models, an Aria P bass and a Peavey PJ bass.  Using the same amp and without adjusting any of the amp controls, I liked the sound of the Peavey when the Jazz pickup volume control was set at zero but the Aria P bass sounded much more like the sound I expect from a good P bass.  Hard to explain but I hope you get the idea of my question.  Thanks as always.

ICBM

I think there can be a small amount of interaction, but it’s pretty minimal. It’s most noticeable with P90s on something like a double-cut Les Paul Special where they’re relatively close together, and a Strat. PJ pickups are probably close enough, but I doubt it’s the reason for the difference.

More likely is that the Aria is just a better-sounding bass - the instrument, not the pickup. Despite popular dismissal by ‘sceptics’, the resonance of the instrument absolutely does make a difference to the amplified sound - provable with proper testing.

guitarfishbay

Yes but it’s so minimal it wouldn’t affect my purchasing decisions if I liked the bass. At least assuming you don’t have a pickup unnecessarily close to where it could interfere (HH Stingrays come to mind)

I’ve owned 3 different Dingwall basses and tried them with 2 pickups and 3 pickups. I do think they respond slightly better with 2 pickups but having 3 pickups gives a more comfortable rest and all the sound options I want. 

fretmeister

Other factors make a difference too - pickup height makes a really big difference on magnetic pull on the strings as well as the basic strength of the magnets used.

Can be more of a problem when the J pickup is a very powerful one to match the output of the P pickup. The P is higher output for 2 reasons, firstly due to it just being a more powerful design, but secondly because the string movement at the P position is far greater than the quite limited movement near the bridge. More string movement = more current created in the pickup.

Many PJ sets compensate by providing a more powerful J pickup so their outputs are as close as possible.

Personally - the best PJ set I ever used was active. The EMG PJ-X set. The main reason why EMGs work so well for this purpose is they have very low string pull. They have been designed that way and as a result have very low power magnets which would normally result in a low output. But inside each pickup there is a tiny preamp to boost the level to where it needs to be. The outcome is very very low string pull, but quite a loud output.

The string pull on the EMG active bass pickups is so low that their heights can be raised to almost touching the strings with none of the usual problems / warbling that would happen with other types.

All of my 2 pickup basses use EMGs for that reason. Contrary to popular belief the EMGs do not sound "active" or "wrong" or whatever, they were actually designed to sound like original Fender pickups but without the downsides.

There is 1 issue with them - the tone control doesn't knock off as much treble as I would like. There's less range on it than with a traditional passive set. But my amp has tone controls so it's not really an issue.


My straight precisions use Aguilar AG4P precision pickups. They sound quite different to the EMGs - they are a recreation of 1960s Fender pickups and are made using 60s construction. Aguilar do a PJ set with a calibrated  to go with it, but I haven't tried that yet. I'm very happy with my current basses so I'd need a new bass to try that out.

Shame!

Funkfingers

Everything that ICBM and fretmeister said.

My Squier VM Precision Bass has DiMarzio Will Power and Ultra Jazz pickups. I chose these in the interests of signal balance. 

The EMG-GZR PJ pair is passive and fully noise-cancelling. The J pickup sound is usable but could do with being a smidge hotter.

My favourite pickups for output balance are the (long discontinued) Seymour Duncan Active EQ "switch" series.

Rocker said:

I tried two basses today, both lowish price models, an Aria P bass and a Peavey PJ bass.  Using the same amp and without adjusting any of the amp controls, I liked the sound of the Peavey when the Jazz pickup volume control was set at zero but the Aria P bass sounded much more like the sound I expect from a good P bass.  Hard to explain but I hope you get the idea of my question.

Clearly, you do not require the J pickup.

If the Peavey bass is a Milestone model, its pickups will be dogbreath stud poles and underslung ceramic bar magnets affairs. If you like the playability but dislike the sound, there is an argument for removing the stock pickups and upgrading to just a P pickup.

It is probably worthwhile upping your budget a little to buy an instrument that does not need anything replacing.

Rocker

@fretmeiste, thanks for your detailed reply to my question. Do EMGs need a battery and/or changes to the pots or controls?  Is fitting them in a bass any different to passive pickups?

Dave_Mc

ICBM said:

I think there can be a small amount of interaction, but it’s pretty minimal. It’s most noticeable with P90s on something like a double-cut Les Paul Special where they’re relatively close together, and a Strat. PJ pickups are probably close enough, but I doubt it’s the reason for the difference.

More likely is that the Aria is just a better-sounding bass - the instrument, not the pickup. Despite popular dismissal by ‘sceptics’, the resonance of the instrument absolutely does make a difference to the amplified sound - provable with proper testing.

Does the extra volume pot load down the signal at all? I'd never thought of that before, but someone else mentioned that on here recently (apologies, I forget who!) and I was wondering if that's correct or not.

fretmeister said:

My straight precisions use Aguilar AG4P precision pickups. They sound quite different to the EMGs - they are a recreation of 1960s Fender pickups and are made using 60s construction. Aguilar do a PJ set with a calibrated  to go with it, but I haven't tried that yet. I'm very happy with my current basses so I'd need a new bass to try that out.

Shame!

You're not looking at that the right way! 

Funkfingers

EMG low impedance pickup systems require a power supply for the pre-amplifier inside each pickup and for any tone controls capable of boosting as well as cutting specific frequency bands.

The easy approach is a +9v PP3 concealed somewhere inside the instrument. 

The more awkward approach involves external powering but that is probably not relevant to this Discussion.

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Instruments such as the Musicman Stingray run a conventional passive high impedance pickup through buffered active EQ.

The dear old P Bass is very simple. Magnetic pickup through two pots and an output jack socket. Despite this, it manages to anchor the low end of more recorded music than any other design.

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The Aria and Peavey bass guitars you mentioned earlier will have volume and tone pots of either 250 or 500 kOhms.

Fully active pickup systems tend to have 25, 50 or 100k pots.

The battery that powers such systems is switched on and off via the "ring" contact of a three-contact jack socket.

Fortunately for you, EMG supply all of the bits in the box. On recent stock, this will be their Solderless™ wiring harness. Everything plugs together via pins and block connectors. No soldering required.

The EMG-GZR Geezer Butler signature pickups are passive but also use solderless interconnect cables. It is possible to purchase the P type pickup singly. It would be easy to integrate a stacked knobs treble/bass active EQ - especially if the output jack socket is already edge mounted.

ICBM

Dave_Mc said:

Does the extra volume pot load down the signal at all? I'd never thought of that before, but someone else mentioned that on here recently (apologies, I forget who!) and I was wondering if that's correct or not.

Yes, in a typical Jazz or PJ circuit the unused volume pot loads the signal even when turned fully off - it halves the resistance the used pickup sees. This does make a difference to the tone.

It is relatively small though - I could be wrong, but if one bass sounds like a proper Precision and the other doesn’t, I think the difference is more fundamental than just the load on the pickup, or even the pickup.

Even two P-basses of exactly the same model can sound remarkably different - a friend bought a MIM one a while ago which sounded terrible, dull and soggy. Luckily he was able to return it, and bought another identical one which sounded great. The difference was in the physical instrument, not the electronics.

Dave_Mc

ICBM said:

Dave_Mc said:

Does the extra volume pot load down the signal at all? I'd never thought of that before, but someone else mentioned that on here recently (apologies, I forget who!) and I was wondering if that's correct or not.

Yes, in a typical Jazz or PJ circuit the unused volume pot loads the signal even when turned fully off - it halves the resistance the used pickup sees. This does make a difference to the tone.

It is relatively small though - I could be wrong, but if one bass sounds like a proper Precision and the other doesn’t, I think the difference is more fundamental than just the load on the pickup, or even the pickup.

Even two P-basses of exactly the same model can sound remarkably different - a friend bought a MIM one a while ago which sounded terrible, dull and soggy. Luckily he was able to return it, and bought another identical one which sounded great. The difference was in the physical instrument, not the electronics.

Thanks

I would suspect it might make less difference on a bass than a guitar? That's just surmise though, I haven't tested it- I've only got a PJ. Just considering there's less treble on a bass usually, and that's usually where you notice the loading difference.

fretmeister

Rocker said:

@fretmeiste, thanks for your detailed reply to my question. Do EMGs need a battery and/or changes to the pots or controls?  Is fitting them in a bass any different to passive pickups?

Yes.

But they come with the pots, battery harness, and the output socket. No need to buy them separately. You just add the battery.

The new socket is stereo as it uses one of the contacts to turn the system on when plugged in, and off again when unplugged. The batteries last a long time - but always unplug the guitar cable anyway.

When I'm gigging I have a little sticker on the back of my headstock with the last battery change date written on it. I change them once a year.

Fitting is actually far easier - EMGs come with a non-solder plug & socket system so everything just plugs together. Just need a screwdriver.




I do wish all pickup makers would adopt the plug/socket approach. Would make quick swaps a lot easier.

JCA2550

@fretmeister , sorry not to derail the OP's thread,  but I'm assuming you have EMGs in a Jazz, tempted to try a set in my CIJ Geddy Lee,  what do you think?

fretmeister

JCA2550 said:

@fretmeister , sorry not to derail the OP's thread,  but I'm assuming you have EMGs in a Jazz, tempted to try a set in my CIJ Geddy Lee,  what do you think?

I do, well it's a Sandberg but it's still a jazz.

I went with the basic EMG-J set for that as those were designed to be like 1960s in sound. I later added a 3 band EQ as well, mainly because when gigging with my big band I often cannot reach my amp to get to the controls at a gig (there's 25+ of us on the stage) so I wanted more control on the bass.

The Geddy stock pickups are a bit more trebly that the regular EMG-J, but they now have some other options too like the X series that have more headroom.

I have mine set to only have 1mm clearance from the strings when fretting at the last fret. No magnet pull, just a great loud signal.

I won't be swapping them again, I'm really happy with them.

Funkfingers

fretmeister said:

Just need a screwdriver

… and a couple of small spanners (or, an adjustable).


I agree that the pin and block connection system aids quick changes. This is of greatest help at the pickup end of the cables and for changing between EQ accessories.

The downside is that the pot PCBs, pins and interconnection cables occupy a lot of control cavity real estate.

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Meanwhile, I appear to have added two more Ignore Lists to my collection. There ought to be a league table for this.