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Won the Wal pickup on ebay!!!

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WarriorJoe7

WarriorJoe7

Inactive
Mar 12, 2004
6,316
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Syracuse, NY
www.myspace.com
#1
:)

Anyways I know that their are alot of wires coming out of it since each pole piece is like one individual pickup.

So how complicated does the preamp look. I'd like to see a picture from a Wal owner... It'd be nice to get a copy of the preamp made but that's asking alot.

Joe
 
#4
From the pictures on eBay, I reckon there are four coils. Each coil senses two strings. If you look at the picture of the bottom of the pickup, you can see four screws, each holding a coil? You can then have two coils switched as a Jazz pickup, a P-pickup, or all of them together as a musicman pickup. Not sure if it works this way, but if the screws indeed hold four coils then this is a possibility.
The pickup is a great find, but I am really curious to see their preamp circuitry. Apparently that's a thing of beauty indeed!

Best regards,

Jarno.
 
#6
By the way, I was just browsing through Melvyn Hiscocks book, and on page 157 there is a picture of a half finished Wal pickup. It's a five string pickup, and the more modern version with the wooden cover. The coils are soldered on a pcb, and there is one coil per string, but that's just one row of polepieces, there is another row below which, in the picture, doesnot have coils (perhaps they left these out for the picture).
The five string pickup has 6 leads, probably one common and one for each string. Does yours have five?

Interfacing this to a preamp would involve rolling your own, I think. It's not that hard. You could also make a mixer in which you can adjust the level of each string/coil, this has a single output which you can then put into a commercially available (onboard) preamp.

Best regards,

Jarno.
 
#7
My plan was to Make series parallell options at more than one level. You could make 2 individual poles either series or parallell to each other then make that pair either series or parallell to another pair, and then if its broken up that way make each quad series/parallell to the other quad. You could also set it up so that each coil has it's own switch whether it's series in relation to the main group or parallel to it. So you could have all of the switches in position A, all will be in series. Or you could have 1-7 coils switched to side B, which would be series on that side, but parallel to the series group on side A. Add in and out of phase to the mix (probably would only want to have one of these switches for matched quads) and you got yourself a ton of options just based on the amount of coils.

I plan to figure out how it works by looking if possible or connecting 2 leads at a time to see what strings make sound (or taps with an allen wrench.)

It would be nice to see what the preamp does, or atleast see a pic. Heck what are the normal control layouts of a single pickup Wal, i don't even know.
 
#8
I replied in the wal settings thread in basses as to your inquiry.

AC guitars makes a low pass filter preamp you may be interested in (wals use low pass filters). Given how much a LPF filter can work with the sound, it may be one of the more important keys to a wals sound?

Still, I'd love if you kept us updated on the status of your wal pickup, I'm anxious to know how much of the wal tone comes from the pickups.
 
#9
There is a picture of the preamp in Melvyn Hiscocks book as well, a very neat and large control cavity filled with two boards.
Not sure if you can use these pickups passively, they might be low impedance pickups with an equally low output. You might get away with "blending" them passively and then go into an available preamp.
Looks like a nice project! Too bad it's only a four string pickup.

Best regards,

Jarno.
 
#10
WarriorJoe7 said:
:)

Anyways I know that their are alot of wires coming out of it since each pole piece is like one individual pickup.

So how complicated does the preamp look. I'd like to see a picture from a Wal owner... It'd be nice to get a copy of the preamp made but that's asking alot.

Joe
Click to expand...

Are these any help to you, Joe, or do you need to see the whole circuit board :hmm:?

136-3626_IMG.jpg

136-3609_IMG.jpg


Either way, I've sold the bass now, so I don't have anything else to show you :(.
 
#11
Thanks man, Just wanted to see whether these are able to be duplicated, and yes they are. Some builders coat their boards with somehing like black epoxy. Now it's just the impossible manner of getting one of these circuits. If one came up I'd spend the dough, reverse engineer it then sell it for close to what I got it for.
 
#13
Fender32 said:
Are these any help to you, Joe, or do you need to see the whole circuit board :hmm:?

136-3626_IMG.jpg

136-3609_IMG.jpg


Either way, I've sold the bass now, so I don't have anything else to show you :(.
Click to expand...

I bet that alot of the sound that the Wal electronics have come from the Thompson (AVX) film/foil caps (the yellowish boxes). Most newer preamp makers use Electrolytic's or some type of ceramic (disc or MLCC), which are cheap and usually have a higher (crappy) operational tolerance.
 
#15
jazzy grille said:
I bet that alot of the sound that the Wal electronics have come from the Thompson (AVX) film/foil caps (the yellowish boxes). Most newer preamp makers use Electrolytic's or some type of ceramic (disc or MLCC), which are cheap and usually have a higher (crappy) operational tolerance.
Click to expand...

IME, what made the Wal tones so "unique" was the fact that you have complete control over each individual pickup and can blend them as you see fit :). By using a very "scooped" sounding back pickup with a blend of heavy-bottomed front pickup, for instance, you can get a kind of 3-dimensional tone that you just won't find on a bass with a single active tone circuit :hmm:.

Just mentioning that, as it's a point that always seems to get over-looked when discussing Wal tone.

:)
 
#17
WarriorJoe7 said:
:)

Anyways I know that their are alot of wires coming out of it since each pole piece is like one individual pickup.

So how complicated does the preamp look. I'd like to see a picture from a Wal owner... It'd be nice to get a copy of the preamp made but that's asking alot.

Joe
Click to expand...

Each string has two coils, so think of it as 4 humbuckers. They probably did active summing on each pair, and then treated them as four pickups, repeating that for each set.

The preamp would have two sections, one to just amp up the pickup, and then the other for tone shaping.

At the very least you need a buffer for either each pair, or you can wire the whole thing up like the passive WAL's, but what fun is that?

Any chance you can take a resistance reading of one coil?
 
#18
There's a common ground and a hot for each string (2 coils). The preamp has an op-amp buffer per string per buffer which allows the pickup to be very low impedance. You will need some sort of buffer per string, if you try to sum all the hot leads together in parallel the pickup isn't going to be anywhere near hot enough.
 
#20
Skelf said:
You certainly need some sort of interface between the pickups and the pre-amp. I have one of my pre-amps in a Wal and this would not have been possible without John East doing all the clever stuff to get it to work.
Alan
Click to expand...

I would be really interested in a review of that, ore even an A/B with a standard Wal if possible (not that you don't have your hands full already).
 
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