# Octaves, Zouks, Citterns, Tenors and Electrics > Four, Five and Eight-String Electrics >  Mandobird pickup upgrade success, mostly.

## high_lonesome_sound

I took the plunge and got an EMG select Pbass pair from Stew-Mac.  Installed half of it on my 8 string Mandobird using this http://www.guitarelectronics.com/product/WDUPH1101 circuit, and I think it's going to be nice.  The pickup fits perfectly into the Mandobird body with no modifications.

A note for others, my tailpiece/bridge ground was awful till I took off the tailpiece and improved the contact between the groundwire and tailpiece/bridge.  Sloppy installation by factory on an otherwise decent instrument.

The EMG select gives pretty even response, the E string sounds good.  Much higher output from this pickup than the original one.

One problem is when I turn the volume and/or tone pots down (from loud to soft, from treble to bass) a very powerful hum kicks in.  I'm looking for a ground problem, but may have burned the pots soldering. *Any ideas?*

----------


## thistle3585

Could be several things...
Overheated a pot during soldering
A bad pot
A bad solder joint
A grounding loop
The lugs are wired backwards ie: input into output etc.  This is common with the wiring between the volume and tone pot.  

Its just trial and error. Post a picture of the control cavity and maybe someone can spot the problem.

----------


## John Flynn

A few things I found out when doing the same thing to a Mandobird: The pots that come with it are cheap. You would do well to upgrade to 500k pots and a .022 cap. You will have to get "mini" pots. The big ones won't fit, and you will have to ream out the holes a little. But you will get much better treble response with your new pickup, which is a traditional 'bird weakness. Also, if you really want to stamp out hum, copper line all the electronic compartments (you can get copper foil for this purpose online) and use a "star ground" circuit. You can find instructions on both on multiple electric guitar sites online. The star ground bascially means you set up parallel paths for all the grounds that meet in one place, or "star." No ground path is in series. Also, there is an art to properly soldering pots without burning them out. Some discussion of all this in the linked thread:
http://www.mandolincafe.com/forum/sh...soldering+pots

----------


## high_lonesome_sound

Thanks for both responses.  I owe both of you gentlemen (and others on this topic) a big debt as I have read your previous posts and that's the only reason I've gotten this far!  I had already learned to use the higher quality 500K pots and .022 capacitor.

And I have to change the title of this thread, to 

*"Mandobird pickup upgrade: success!!!!!!!!!!!!"   
*
I found two errors in my wiring, one case of sloppy soldering, the other a case of not knowing my left from my right.  Fixed them both, and success!

For a $25.00 pickup the EMG select is sounding pretty good to me!

I appreciate all the help! :Grin:

----------


## thistle3585

> ........the other a case of not knowing my left from my right.  Fixed them both, and success!


Yeah, a lot of us suffer from that.  I don't think I realized until my fifth or sixth instrument that the wiring diagram I used was from the perspective of looking down, so I had been wiring all my knobs backwards.  They still worked, but the volume went up when the number on the knob showed it going down.  :Laughing: 

Glad to hear it worked out.

----------


## CES

Not to hijack a thread, but it's kind of in the same vein...I was restringing my bird this weekend for the first time and as I threaded the A string the frayed ends of the bridge ground wire appeared.  I pulled it back a little and everything sounded OK, but I was wondering how that wire's supposed to connect?  Don't think I'll plug it in again until I get more info...starting my search as of now (hence my discovery of this thread and will continue to look), but figured it can't hurt to ask!

Thanks--
Chuck

----------


## mandroid

Chuck,   

the  metal bridge is grounded,  a wire is in contact with the bridge, underneath it.
perhaps it got exposed  in (rather excessively) fast assembly, part of making retail  price so  low.

with the strings off , 
loosen the screws that hold the bridge down, and re position that so its not exposed .

----------


## CES

> Chuck,   
> 
> the  metal bridge is grounded,  a wire is in contact with the bridge, underneath it.
> perhaps it got exposed  in (rather excessively) fast assembly, part of making retail  price so  low.
> 
> with the strings off , 
> loosen the screws that hold the bridge down, and re position that so its not exposed .



Mandroid--

Thanks...will do tonight...I just wanted to make sure there wasn't soldering involved before I got into it (I'm going to Lowes on the way home today anyway).  I wasn't too worried about shock since one of the sites listed above actually recommends disconnecting the bridge ground with vintage amp equipment to avoid potentiating a ground loop, but I'm pretty new to this...

----------


## mandroid

without a ground  to the strings , via  tailpiece , or metal bridge  ..  the thing     [generic] 
hummed   .. when I didn't have my hand laying on the strings

----------


## jlsmandolin1952

You might want to experiment, to get the right soldering Iron, so as not to overheat the pots.
                                John

----------


## CES

Thanks for the advice...yeah, the hum is the big downside to not having the bridge ground.

I shouldn't have to do any soldering unless it's to the bridge somewhere...the solder on the pot looked solid...

I'll post back with commentary if issues arise--

----------


## CES

So, the ground wire had simply been threaded too far and got caught by/pulled up when I rethreaded the A string.  In pulling it back through the back cavity I had unknowingly set it back where it should have been, so removal of the bridge turned out to be an unnecessary step.  But, I did learn that the ground is just kind of floating in the cavity below the bridge...if hum becomes an issue I'll know to secure it, but for now no hum, and I'm happy.  Also got to reset intonation two days in a row, which is always a good exercise given how infrequently I tend to change strings.

Thanks for your help and advice, and apologies for the hijack!

----------


## Hubert Angaiak

Would the wiring diagram you are using be the standard wiring config? I've a Old Town, and Doug O'Dell has it wired differently than that the diagram.  It has a .05 cap between the pots. The pickup is EMG select.  I have to use both pots to adjust the volume and tone of the mando. Its making me think of getting new pots and rewiring and keeping what he had intact... so if someone should want it I'll have the wiring as he had it.  They are 500K pots.

----------


## johntrefz

Hello! Wanted to share my solution to the low output e issue that everyone seems to have with the Stock Mandobird pickup. As you can see in the pic, I super glued a small (approx. 1/2" X 1/16") rare earth magnet to the pickup just under the e strings. Much to my delight, this made the e significantly louder, enough for me to consider the problem fixed. YMMV. Before I tried this, I was going to purchase a DiMarzio P-bass pickup which has adjustable pole pieces. That may be a preferred solution, as it's probably a higher quality pickup to begin with, but I figured I had nothing to lose. So far, so good!

----------

Daniel Nestlerode, 

Verne Andru

----------


## thistle3585

One of the reason the bass pickups aren't so good, other then them not being voiced for a mandolin, is that the rails inside of them are offset because they are designed to be used in pairs and to only cover two strings.  You might try rotating it.  Best solution is an Almuse pickup.  Wont have to compromise a bit.

----------


## Verne Andru

IME bass and mandolin work best with a full-range signal path. In both cases pickups that don't color the sound work best so what works on one should be fine on the other. Mandolin requires mid-range EQ, but that happens after the pickup. Pickups create an electro-magnatic signal in response to the metal in the strings moving over them with a field of motion generally being larger than the pole pieces.

----------

