Looking for advice on bouzouki pickup design

[Mark Hammer]

A work-colleague is one helluva bouzouki player. His custom-made (in Greece, natch) bouzouki is his pride and joy, and I can say from first-hand experience it is the bouzouki equivalent of a PRS Dragon in terms of workmanship and visuals.

Unfortunately, the EMG soundhole pickup he has mounted in it crapped out on him the other day, and none of us can figure why. The pickup itself is encased in epoxy and the three pins coming out of it do not measure anything like what I'm accustomed to (min resistance between any two pins is 60k). There are appears to be no problem with the secondary electronics. Just no signal coming out of it.

In any event, I thought I'd take on the challenge of winding him a conventional passive pickup (maybe HB) that could do the job. I can turn to all manner of public and printed information and folk-wisdom about guitar pickups, but as you can imagine bouzouki pickup lore is a little sketchy and intermittent. (!!) I have the impression that it will be something similar to a mandolin pickup in its goals, except at a lower pitch.

So, anyone have any experience making a (neck) pickup for a bouzouki? What sorts of coil parameters should I aim for and what sort of DCR should I anticipate? Just looking for some general pointers so that this baby can sound as beautiful as it looks.

[Merlin]

Hi.
It is my first post here so hi to everybody.

Mark, look here: http://www.merlinpickups.com/custom.htm
I made a bouzuki humbucker pickups for my friend. In his opinion pickup is ok, sound clear, brigth and dynamic.
I used 0,06mm wire, AlNiCo 5 magnets rods dia 5mm/17mm long. DCR is aprox 2KOhm per coil. Unfortunately I didn't write the number of turns down . Maybe it helps you.

[David Schwab]

The pickup itself is encased in epoxy and the three pins coming out of it do not measure anything like what I'm accustomed to (min resistance between any two pins is 60k).

Two pins connect to to the output of the internal preamp/buffer (ground and signal), and the third is for the 9 V battery.

You wont get any kind of reading as far as the coils go.

Is the battery connection good?

[Mark Hammer]

As near as I can tell, the battery connection is fine. Plug a phone plug into the stereo jack and you get 12vdc just like you're supposed to. The coil itself is just dead to the world. Nothing, nada, 0mv AC. My friend says it just "gave out" while playing (given that this week is Greekfest and he's a star player, that was kind of disconcerting...in every sense of the word).

From your comments and from what I saw last night, there are semiconductors in between the actual coil and the three pins connecting to the interface board housing the lithium batteries (http://www.emginc.com/displayproduct...&catalogid=66).

Unfortunately, as noted, the whole thing is encased in epoxy so there is really nothing to repair, just something to send back.

[Mark Hammer]

Greeting from Canada! (my father's family came from Lodz)

I will probably use ceramic button magnets under some steel polepieces, but I like your design. This is like the Fender Precision Bass pickup, and also like the old Evans Eliminator pickup. I imagine the DCR *is* quite low with a coil of that circumference. You can probably put 6000 turns on each coil and still have something with a very low DCR. I will probably use #41 wire because it is what I have.

My friend tells me that the A string on a bouzouki (the 2nd string on the treble side) usually has a problem being too loud. I guess this is like the unwound G string on a guitar. I'm going to try and use a staggered-height polepiece for that string and see if it helps.

[EtLa]

I did something similar to merlin that look like this.

[Mark Hammer]

That might actually be a good idea in my case. I ended up using some ceramic rod polepieces (!!?) that I had, in a dual-coil configuration. The polepieces are a relatively "normal" diameter, but since the bass strings consists of a wound+unwound combination and the upper strings consist of matched unwounds (like on a 12-string guitar), I'm concerned that the polepiece spacing might not suit the strings perfectly.

Seeing your diagram, I think what I will do is make a bracket for underneath the coils (like you did) with a slot cut out along the middle. The coilforms have a Fender-style hole midway between the polepieces (so I could mount the bobbin for winding). I can run a nylon screw through there to the other side of the slot underneath and tilt (like you did) or adjust the side-to-side positioning of the coils, securing the nylon screw/bolt once I get optimal string balance.

Thanks for the idea!

[EtLa]

What I did is used black ABS for the bracket and the coil and glued the coil in place on the bracket and ounce dry I added a screw under the bracket for securing each bobbins.