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sonofzorro1
New
Username: sonofzorro1

Post Number: 1
Registered: 6-2012
Posted on Thursday, June 14, 2012 - 10:44 am:   Edit Post

Hi, Alembic bunch.
I am a newbie to the group, and not yet an alembic owner (cannot afford one right now, my son is going down south to start at Northridge State with Gary Pratt...the boy wants to be a pro bassist). I do have some pickups that I got on EBay, and am hoping to attach them to a Demeter preamp. Teh P-bass set has the orange two-port connector, that seems straightforward enough, though it would be nice to have the male connector to attach to the pre, instead of jury-rigging a solution. The bridge pup has a different type of connector. though. It is a wire with a sort of crimped-on looking thing that is cylindrical with a hole up the center. Not sure how to adapt for that thing. Any advice? (pics attached)

pickup pics
pickup pics
pickup pics
sonofzorro1
New
Username: sonofzorro1

Post Number: 2
Registered: 6-2012
Posted on Thursday, June 14, 2012 - 10:52 am:   Edit Post

Here is a pic of the P-bass pups...
pbass pups
adriaan
Moderator
Username: adriaan

Post Number: 2942
Registered: 6-2002
Posted on Thursday, June 14, 2012 - 10:58 am:   Edit Post

I seem to remember the cylindrical connector was used in the 1970s, whereas the embossed emblem perhaps suggests it's a later pickup. One would guess it's a single-coil pickup to go with Series electronics and a dummy humcanceller pickup, but what do I know? ;-)

The other connector usually hooks up with a small base unit that is mounted on a small pcb on which (part of) the Alembic electronics are mounted.
mica
Moderator
Username: mica

Post Number: 7774
Registered: 6-2000
Posted on Thursday, June 14, 2012 - 10:58 am:   Edit Post

Hi Daniel, welcome to the club! The pickup with the gold coaxial connector is not a good choice for the proposed electronics setup since it's a single coil design and will hum like a beehive without the complete humcancelling circuit. This is a SC-1 pickup, and it's for the Series I and II basses.

For the pickup with the 2-pin header in the first picture, it might be best to cut a 1-2" length off and strip the remaining wire and connect to the preamp that way. You will preserve the crimped connectors inside the housing if you add them to an Alembic circuit later you can splice the wire back (don't forget the shrink tubing!) to the pickup and go modular again.

There's a couple of FAQs on the pickup connectors you might find interesting: 2-pin connectors, coaxial connectors.
sonofzorro1
New
Username: sonofzorro1

Post Number: 3
Registered: 6-2012
Posted on Thursday, June 14, 2012 - 10:42 pm:   Edit Post

Thanks for the responses, Adriaan and Mica. Sounds like the P-Bass pup should be paired with a humbucker or used by itself, and the SC-1 by itself or with another single coil with reversed wiring (RWRP) to control hum?
Are the coax pin connectors and wiring something that is currently available from a supplier? Not sure how to deal with the coax cable otherwise.
And which Alembic pickup should be paired with the SC-1?
jazzyvee
Senior Member
Username: jazzyvee

Post Number: 2962
Registered: 6-2002
Posted on Friday, June 15, 2012 - 12:05 am:   Edit Post

The P-Bass pickups will be hum cancelling pickups so do not need to be paired with another pickup, they can be used on their own. I have that style of pickup in my Elan bass.

Jazzyvee
keith_h
Senior Member
Username: keith_h

Post Number: 1756
Registered: 2-2005
Posted on Friday, June 15, 2012 - 6:24 am:   Edit Post

The SC-1 would be paired up with another SC-1, a hum cancelling coil and hum cancelling circuitry.

The typical configuration for non-Series pickups would be one or two hum cancelling pickups (sometimes referred to as Activators). The various styles are AXY, MXY, Jazz Bass and P Bass (there have been other variations over the years).

Keith
sonofzorro1
New
Username: sonofzorro1

Post Number: 4
Registered: 6-2012
Posted on Monday, June 18, 2012 - 12:31 am:   Edit Post

Thanks, Kieth and Jazzyvee. Here is a pic of an Alembic preamp that I could buy. I gather that this would work for my P-bass pickup. But when you cats mention " a hum cancelling coil and hum cancelling circuitry", are you talking about something that only Alembic single coils need, a part of the electronics package in the preamp? All my single coil basses just have two pups that are reverse pole reverse wind with respect to each other. I have also read that if the two pups are humming, just reversing the wires (ground and hot) on one pup will ameliorate the problem. It seems that the pictured preamp might just work on a single SC-1 as well. Am I off base here? Thanks. Daniel
Alembic Preamp
Alembic pre

(Message edited by mica on June 18, 2012)
dfung60
Senior Member
Username: dfung60

Post Number: 551
Registered: 5-2002
Posted on Monday, June 18, 2012 - 1:25 am:   Edit Post

The brick-red colored connectors that Alembic uses are Molex connectors with 0.10" spacing. The current generation of these connectors are called C-Grid, but it's not worth trying to buy the male connector. The one piece you need is probably 25 cents, but you'll probably have a hard time buying less than hundreds of them. Even then, they won't be very usable as this kind of connector is typically soldered onto a PC board. That's what they're for - connecting a cable assembly to a PC board in a reliable and disconnectable fashion. Just cut the end off, but (if you've got enough cable), leave a couple of inches on the connector, so you could resplice the connector on in the future. But really, just cut it off and don't worry about it.

The mini coax connector is also still available, but will be very expensive and hard to work with. It's also designed to go from a cable to a PC board and this one is designed to do so minimizing signal loss (it's normally used for radio frequency signals and is overkill for audio).

The story with SC-1 is that this is part of a very unusual electronics setup. It's a low-output single coil pickup, designed to run into a preamp before leaving the bass. A single coil pickup on it's own can hum like mad, so a clever guy like Leo Fender decided to fix the problem by winding the single-coil pickups on a Jazz Bass with reverse winding and reverse polarity (the magnets are upside down). When both pickups are on, the trick pickups create in-phase audio but cancel any hum. If your Jazz pickups are reverse-wound, reverse polarity, then connecting them up in parallel will get rid of the hum. But if the two pickups are identical, then reversing the wiring will get rid of the hum but put the pickups out-of-phase and all the bass will go away too. If you have a traditional Jazz Bass, you probably never noticed this, but the bridge pickup is wider than the neck one - this way you never mess up and put two identical pickups in the same bass. But if you have a Fender that was made in Mexico, they actually use two identical pickups (they're exactly the same size too) and it will hum when both pickups are on.

Leo was clever, but Ron W. was working under different constraints. The Alembics have always been "ultimate performance, price is no object". So instead of creating a pair of trick pickups that get rid of hum when they're both on, but hum when you're only using one, he made a system where both pickups are true single coils and they still don't hum.

A Series Bass has two regular single coil pickups that are carefully designed and matched to each other, but there's also a hum cancelling coil that normally sits in between the pickups, flush at the surface of the bass. This coil is just a coil of wire with no magnets, so it can't sense the motion of the strings. The only thing the middle "pickup" of a Series bass can hear is HUM! This noise-only signal is subtracted from the regular pickup outputs and you get perfect single-coil sound with no hum, even when only one pickup is on (although there are actually two coils working!).

The Series electronics are really wild. To maintain perfect signal quality, the output from the pickups go straight to independent preamps. And so does the hum coil - so a Series bass has a dedicated preamp that just amplifies noise, so it can be subtracted out!

Even though the Series electronics were designed in the 70's, it already embodied a lot of stuff that became popular many years later like 18V power (it's actually higher from the power supply) and more.

David Fung
sonofzorro1
New
Username: sonofzorro1

Post Number: 5
Registered: 6-2012
Posted on Friday, June 22, 2012 - 12:21 am:   Edit Post

Hmmm...Thanks, David, that is very enlightening, and one of the most succinct explanations of the Fender type pickup system that I have heard yet. I guess my problem is that I would need the rest of the Series 1 electronics package to utilize my SC-1 bridge pickup. I know where to get the humcanceller (middle pickup) for a reasonable price, but not the neck pup or the bi-preamp system to bring it all to life. It sounds like I should throw in the towel rather than throw good money after bad, unless somebody has a suggestion or I get lucky and find someone with a Series 1 set of electronics to sell on Ebay! Series 1 humcancellor pickup
dfung60
Senior Member
Username: dfung60

Post Number: 552
Registered: 5-2002
Posted on Friday, June 22, 2012 - 7:42 pm:   Edit Post

I guess you could consider getting the humcanceller and build a one-pickup system. I don't think there's any difference between the pickups (please correct me if I'm wrong!). The canceller doesn't have any value without the pickup that you already have.

You'd need a matched set of preamps to combine the two signals, but this could be as simple as a single dual opamp, which is not an expensive component.

By the time you rout a body to accept this stuff and build a custom circuit, it's probably not worth the effort.

David Fung
edwin
Senior Member
Username: edwin

Post Number: 1210
Registered: 5-2002
Posted on Saturday, June 23, 2012 - 2:09 am:   Edit Post

I'm wondering if you got the SC-1 from the ebay auction that happened recently. I thought it was pretty obnoxious that the guy sold all three separately since they should be a closely matched set. Making the electronics is not crazy difficult, although it is important to set it up to be as low noise as possible.

I bought a set of Series pickups (older caramel colored) and a SI circuit board and wiring harness (that was pretty much shot, so I rebuilt it) and put it in a bass, but I went into it knowing that it was what I really wanted. If it's not what you really want from the get go, it's probably not worth it. I would try to get in touch with the person who bought the other SC1 and try to reunite all three pickups. They have value as a set and very little value by themselves.
sonofzorro1
New
Username: sonofzorro1

Post Number: 6
Registered: 6-2012
Posted on Sunday, June 24, 2012 - 10:55 am:   Edit Post

Thanks, David and Edwin. Yes, my pup is the one that was on EBay. The seller is working in good faith with me on the Humcanceller, he is bending over backwards to make the purchase work out for me. Hopefully the other buyer will sell me his neck pup at cost plus shipping, but I think I might buy the humcanceller on spec, and look forward to building up the system in the future. Where did you get your Series one electronics, Edwin?
Were could I get a "single dual opamp" that will combine the two signals, David? I looked up the Series 1 bass that the seller of my pickup sold on EBAy...he got 4500 bucks for it. I don't currently have that much to spend, but I have built some interesting retrofit basses that worked out well, so I like a project that might give me something of the Alembic experience (I have never even seen an Alembic bass, much less played one!). I have some bodies and necks lying around waiting for me to work on, so this is an attractive project if it can be made to work.
Daniel
dfung60
Senior Member
Username: dfung60

Post Number: 553
Registered: 5-2002
Posted on Sunday, June 24, 2012 - 7:02 pm:   Edit Post

Daniel -

The Series basses have a PC board in them that has three single op amps (one for each pickup and one for the canceller). The op amps themselves are very simple IC chips (it was one of the first commmerically succesful ICs) and there's a few external components to configure their operation.

I opened up one of my Series basses (from 1981) and found the original chip was a Signetics NE 55534AM. That chip's not made anymore (Signetics is part of Phillips now), but they're still gettable for something like $10 each. This is a high performance, low distortion opamp suitable for audio preamps. This part was also widely known as the TDA1034. You've hear people comment that Series basses don't last long on batteries - this part is famous for having high performance at the cost of very high power consumption.

There are many modern equivalents that actually have the same pin arrangement. One of the common ones today is the TL072 which is the same size chip but has two independent amps inside it, so one chip can handle both the pickup and canceller coil. A popular chip this this probably costs only $0.50 (if you can figure out a way to get only one instead of a package of 1000). TL071 is the same pins as the 55534, but the components around it would probably need to be different.

You'd need somebody to build you a board with the electronics on it. There's not much there, but it may not be worth the cost (this would be like having somebody build you a custom fuzz box).

Hope this helps,

David Fung
sonofzorro1
New
Username: sonofzorro1

Post Number: 7
Registered: 6-2012
Posted on Monday, June 25, 2012 - 1:26 pm:   Edit Post

Thanks, David. you clearly have more knowledge of electronics than I. I guess I would need to track down some specs or a wiring/circuit diagram for the board, and find someone to interpret and build it, if I could not find a used Series 1 preamp somewhere. Kind of sounds like a tough project for someone who knows as little as me. Hmmmm....
edwin
Senior Member
Username: edwin

Post Number: 1213
Registered: 5-2002
Posted on Monday, June 25, 2012 - 4:14 pm:   Edit Post

I got my Series electronics from someone on ebay. It was basically the board and a pile of parts, most of which I replaced. While it's not a crazy difficult circuit, I would not suggest it for a beginner. I also believe that tuning the whole thing to work just exactly right is not trivial. While the SII setup I rebuilt does function, it's somewhat noisy. My SI is dead quiet and Ron worked for a long time to make it so. I don't know what he did, but whatever it is, he's very good at it and it adds a lot of value to factory setups.
sonofzorro1
New
Username: sonofzorro1

Post Number: 8
Registered: 6-2012
Posted on Thursday, June 28, 2012 - 2:40 pm:   Edit Post

Thanks, Edwin. I think I will keep my eyes open for a while, and see if anything useable comes up for sale. Interesting custom setups are a hobby of mine, learn as you go, you know? Here are a couple of projects...
Who is this Ron cat?
Italia bass, built-in piezo, Armstrong lipstick-tube bass pup, Bartolini piezo buffer to balance them.
Squire Tele bass body, Allparts neck, Fender Wide-Range neck pup, Armstrong bass pup.custom bassescustom bassescustom basses
jacko
Senior Member
Username: jacko

Post Number: 3203
Registered: 10-2002
Posted on Friday, June 29, 2012 - 4:34 am:   Edit Post

Daniel.
This 'Ron cat' would be Ron Wickersham, founder of Alembic. You can find full details of the company's history here

Graeme

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