Music Man bass pickup wirings

[Marco Pancaldi]

Hello,

I'm trying to replicate, with a Nordstrand MM pickup, the different wirings from some Music Man basses, with "parallel", "single" and "series" combinations.

I know very well the tone/volume variations when switching guitar humbuckers from series to parallel, but I'm little confused here: passing from the (standard MM) parallel to series wiring gives a huge level increase, impossible to use without reset the volume pot to about half volume (to "5" in my case as I'm using 250k linear pots). At this point, maybe due to the pot resistance introduced (about 125k) the series tone is very similar to the parallel: only the very high end is a little more dull, but the "body" is not much different from parallel.
I remember some years ago I made a series/parallel test with a common split P-bass pickup and I was unimpressed (parallel = less volume and no more) and I kept in that case the original wiring untouched.

So, my question is: did you have the same experiences?

More: searching the net I've found incomplete (non-factory) schematics from MM Sterling and discovered that what they call "series" wiring is not a passive one: the coils are separatley buffered and mixed, so it is more a "buffered parallel", in opposite to the real, passive parallel wiring (as used in the original Stingray model).


Any observation welcome, thanks
m.p.

[Jim Shine]

Not sure what you are looking for. I have detailed information about CLF Research's era (1976-1980). From tooling through production including notes Leo made about eventual revisions. But I am not sure how any of it applies to what you are looking for.

Sting Ray's had different pickups than Sabre's. They had unique to each other preamps as well.

[bajaman]

You may find this of interest ;-)
freestompboxes.org ? Login
cheers
bajaman

[big_teee]

You may find this of interest ;-)
freestompboxes.org ? Login
cheers
bajaman

Why did you post the freestompboxes login page?

[rjb]

Also not sure what you're looking for.

You say you have a Norstrand MM pickup, and when you switch it from parallel to series mode, you get a huge volume increase- and after compensating for the volume change, the tone difference is insignificant.
You also say you've had similar results with a split-P pickup; switching from series to parallel decreased volume but had insignificant effect on tone.

I'm guessing that in both cases, you used a 250K linear volume pot.

I can only say that I've used a DiMarzio Model-P with a series/parallel switch, and there definitely was a tone difference between the settings.

Just going by intuition, I would suggest trying a 500K audio taper volume pot.
The higher value could "open up" the high end so that you hear the brightness in parallel mode.
With audio taper, you wouldn't have to turn the knob so far to compensate the volume.

Is this the (partial) wiring diagram you're working with?
http://nordstrandpickups.com/wp-cont...up-Diagram.pdfI

Edit: Yikes, maybe I'm totally confused.
I have no experience with MM basses or pickups.
Were these pickups designed specifically to be used with a pre-amp?
Are they hot enough to be used passively?
Are you using them passively?
Mention of split PBass pickup and 250K volume pot made me assume "passive".

[bajaman]

I posted the freestompboxes.org login page because I started a 20 page thread about the Music Man bass pickup preamp. If you are a member (free to join) there is lots of info there for all to see ;-)

[mr fab]

i recently fitted two MM pickups in a jazz bass

and used a 3 switch plate as used on teh fender VI to series parallel each pickup, and the last remaining to split both pickups to give a quasi jazz bass tone.
i have used the bass live and it sounds great, and there are so many tones available

series coils sound full and direct
parallel coils sound bright and funky
split, somewhere between the two

yes there are volume differences, but you accommodate that with your technique

whilst i am not sure what you are after, i hope the above info helps somewhat,

the bass i have is passive, and if you are worried about the differences in volume, then i suggest you use a compressor to even it all out

i personally like the fact that there are volume differences and i can use it to my advantage

[Jim Shine]

Edit: Yikes, maybe I'm totally confused.
I have no experience with MM basses or pickups.
Were these pickups designed specifically to be used with a pre-amp?
Are they hot enough to be used passively?
Are you using them passively?
Mention of split PBass pickup and 250K volume pot made me assume "passive".

Yes, made to be used with the preamp (that page linked talks about one model, Leo made 3 different Sting Ray Bass and 2 different Sabre bass preamps)

They are very low powered. Like 2K. Wound with 42 poly. To get a significantly higher wind count, you have to start messing with the original coil design, which alters the sound.

[rjb]

Yes, made to be used with the preamp...

They are very low powered. Like 2K. Wound with 42 poly. To get a significantly higher wind count, you have to start messing with the original coil design, which alters the sound.

i recently fitted two MM pickups in a jazz bass
|
the bass i have is passive,

1) Jim & mr fab: You guys are talking about the same pickups, yes?

2) mr fab: That sounds like a nice setup. Could you elaborate on volume & tone control values you used?

Edit:
3) m.c.: You are using one pickup with a passive circuit, yes?

Just trying to sort this out,
-rb

[Mike Sulzer]

Changing from parallel to series should increase the volume substantially, with the exact effect dependent on the load the pickups are looking into. Into an infinite load, the increase is about 6 db. If there is a capacitive load such as a cable, the the series connection has a lower resonant frequency. How that sounds depends on where the resonance was with parallel connection.

Hello,

I'm trying to replicate, with a Nordstrand MM pickup, the different wirings from some Music Man basses, with "parallel", "single" and "series" combinations.

I know very well the tone/volume variations when switching guitar humbuckers from series to parallel, but I'm little confused here: passing from the (standard MM) parallel to series wiring gives a huge level increase, impossible to use without reset the volume pot to about half volume (to "5" in my case as I'm using 250k linear pots). At this point, maybe due to the pot resistance introduced (about 125k) the series tone is very similar to the parallel: only the very high end is a little more dull, but the "body" is not much different from parallel.
I remember some years ago I made a series/parallel test with a common split P-bass pickup and I was unimpressed (parallel = less volume and no more) and I kept in that case the original wiring untouched.

So, my question is: did you have the same experiences?

More: searching the net I've found incomplete (non-factory) schematics from MM Sterling and discovered that what they call "series" wiring is not a passive one: the coils are separatley buffered and mixed, so it is more a "buffered parallel", in opposite to the real, passive parallel wiring (as used in the original Stingray model).


Any observation welcome, thanks
m.p.

[Jim Shine]

1) Jim & mr fab: You guys are talking about the same pickups, yes?

I don't know. I am talking about Music Man Sting Ray Bass pickups made between 1976-1980. Ernie Ball continued the 1977-80 configuration into the 90's at least. I am not sure about current models or alternate versions/aftermarket things.

[rjb]

Changing from parallel to series should increase the volume substantially, with the exact effect dependent on the load the pickups are looking into. Into an infinite load, the increase is about 6 db. If there is a capacitive load such as a cable, the the series connection has a lower resonant frequency. How that sounds depends on where the resonance was with parallel connection.

That's what I was gonna say- with twice the verbiage and half the lucidity.

EDIT:
But the question I'm trying to reconcile (for myself) is:
If the pickup impedance is as low as Jim implies, what circuit topology and passive component values are mr fab using to get useful tone changes in the various switch positions?

[David Schwab]

Real MM pickups were always in parallel. Never in series.

Keep in mind that the pickup was never used passive, but always with the preamp, which had quite a bit of gain, and was matched to the 2k impedance of the pickup.

[mr fab]

1) Jim & mr fab: You guys are talking about the same pickups, yes?

2) mr fab: That sounds like a nice setup. Could you elaborate on volume & tone control values you used?

-rb

the pickups i used were alnico v MM replicas. i dont recall the DCR of the pickup... as for pots, from memory, i used 500k pots, wired with 2 volumes and one tone. each pickup goes to one slide switch for the series parallel switching, and then i have the third switch to cut one coil on both pickups so that single runs single.[ATTACH=CONFIG]


40184[/ATTACH]

[mr fab]

That's what I was gonna say- with twice the verbiage and half the lucidity.

EDIT:
But the question I'm trying to reconcile (for myself) is:
If the pickup impedance is as low as Jim implies, what circuit topology and passive component values are mr fab using to get useful tone changes in the various switch positions?

ok i just measured the dcr of the pickups... they are both 7.5k with both coils in series (ie half that per coil)... which means they would measure 1.9k in parallel, but i must say they sound really good in all configs, but i do prefer the sound of both coils in series

david is correct, the original MM guitars and bases had their pickups wired in parallel, i have a 78 musicman sabre guitar and its pickups are wired in parallel, and that that preamp is a monster. i think these guitars were not popular, because of shifting trends in music at the time...ie spandex, big hair and superstrats with FR's

the volume difference between settings is not as large as you may think, its just that series mode sound much fuller.. more like a gibson bass

i love the tones i get from it and it sounds amazing through the 300W bass amp i built