Help me ID these electronics?

[jigme]

Here Fender/Alembic Frankenstein. I am wondering if anyone here can identify what exactly I have here.

The facts:
Bought in 1978 from Petaluma Music, this is  a 1973 Pbass with maple neck and ash body. The original owner was John Rudolph. It is heavily routed (poorly). Originally the neck pickup was in the neck rout. I had a new pickguard made and moved the neck pup into the Pbass position. This helped focus the sound and I have lived with it a long time this way. It originally had a brass bridge that I replaced with a BadAss. I still have the bridge.

I've always believed they are Series I, but would like confirmation, especially since it is, what do you guys call it, a "midnight shop job"?

https://photos.app.goo.gl/GfKKdZxfg8W3m1d56

[rv_bass]

Looks like Series I with master volume to me.  Do you get noise with the hum canceler where it is?  Usually it’s positioned between the neck and bridge pickups.

[jigme]

I don't have a master volume on this, it's standard V,V,T,T, with Q-switch and pickup selector. I haven't noticed any major um with the canceler where it is.


Does anyone think these pick-ups are unusual in any way?


Are the coils on these in the middle of the pup, or more close to the edges?

[rv_bass]

Oh, I see, I mistook the pickup selector on the lower horn as a master volume.  I’m not familiar with the pickup construction, others might be able to help you with that.  Cool bass.

[jigme]

Thanks rv_bass! 

[StephenR]

Pickups are the early style with only two mounting screws. Is there any way to get at the controls that adjust pickup gain and hum canceller? Normally that is done through the back plate (adjustments are on the back of the main circuit board) but there are no pictures of the back of the bass.

[edwardofhuncote]

Interesting that the humcanceller is the caramel colored edition.


Baddest Fender bass on Planet Earth far as I'm concerned. Thanks for sharing. 

[jigme]

Yes, there are the four adjustment screws on the back of the bass for the adjustments.


Thanks EdwardofHuncote! With steel round wounds this thing sounds like the God of Thunder. I can approach that Entwistle tone--great for rock.


I have more questions about strings and tone, but that'll be another post. 

[JimmyJ]

Definitely Series I electronics with the old "flat-pack" opamps soldered to the underside of the board.  I would think that the unusual placement of the hum cancelling coil would reduce its effectiveness, but maybe not.  You may be the first guy to try that!

Why are you asking where the coil is, are you considering trying to shave them down or something?  I don't know the exact answer but I'm going to presume that our large single-coils are, well, large ... and that they probably come very close to the edges of the resin block.  I don't think there's much room to play with there if you're wondering about making them smaller.. 

I bet that bass sounds mighty good!

Jimmy J

[jigme]

JimmyJ-- I don't think the placement of the hum cancelling had a huge effect. I adjusted the screws for it and it seems ok.


I was asking about the pup coils because I wanted to measure their placement and see if they are like a 70's jazz bass, or if the neck pup is where a Pbass would be, or compare it to say, a Sadwosky. I would never modify something like that... too risky!


If anyone has an opinion on how putting the neck pup back to it's original position would change the tone I'd love to hear it!

[lbpesq]

I don't believe placement of the hum canceling PU is critical.  IIRC some very early instruments had the hum canceler hidden inside the body cavity. 

Bill, tgo

[hieronymous]

I can't comment on the electronics but just wanted to chime in that this is a super-cool bass! I have a couple of Alembicized Fenders but with the standard, later Activators - Alembicized instruments with the old-school Series electronics are too cool for school!

[JimmyJ]

Here's my quick and dirty calculation of where the Jazz bass pickups are placed (just based on a photo, so anybody who actually has one can correct me).  The 12th fret on our 34" scale instruments is almost exactly 1" so...  based this picture it looks like the bridge pickup is about 2-1/2" away from the E-string saddle, and the "neck" pickup is about 7".  You can figure that the coil in our Alembic pickups is centered, if that's what you were wondering.

Moving the neck pickup closer to the fingerboard would result in a very deep bass tone.  The further you get away from the bridge, the more of the fundamental note you get.  On my Series basses I tend to run the bridge pickup as the hotter of the two - but it's totally up to the individual.

Jimmy J

[David Houck]

As Bill mentioned, my recollection is that it doesn't matter where the hum canceller is located, and that it was not between the pickups in the earliest instruments.

And it is also my recollection that, like the Fatboy pickups, the magnets inside the Series pickups take up the full space inside the shell; and I'm guessing that's true of these early pickups as well.  In AXY pickups, the magnets are the same size as those in MXY pickups and placed on one side of the shell.

[adriaan]

I think the magnets in AXYs are normally centered, but you can special order AXYs with the magnet off-center.