piezo pickup uneaven

I have a uke undersaddle piezo. The volume from the strings is very uneven. The second string E is almost off and the 1st string A is very loud. Has anyone experienced this. It is not too noticable when stumming but very noticable on instrumentals. Is it pressure. Should I try shimming in this area under the saddle?

It's very common with piezo pickups, expecially the 'non flexible' type. I fixed it in one uke by replacing a 'hard' pickup with a more flexible Fishman. Usually it's down to the bottom of the slot or the bottom of the saddle not being perfectly flat, though I have experienced problems on ukes where the hole for the pickup cable to pass through was a bit on the large side too. I've also just had duff pickups...
There is a 'fix' that a lot of acoustic guitarists use which might be worth a try, as it's not expensive...
http://www.museweb.com/ag/amp/zyla_method.html

It's yet another reason that I dislike piezo pickups (though I have used them for years), and am moving away from using them, but that's another story!

This is not uncommon in relatively cheaper instruments; usually associated with cheap piezo parts and poor workmanship.

It can be due to several different factors, such as the saddle's underside not being even, the saddle slot not being even, etc.

What ukulele do you have?

Phil, that seems like quite the operation!

This uke was not cheap, at least by my standards. It was approximately 3K. I will try the shim but I guess the easy fix would be a K&K at my next visit to a large town.

I have read some other posts where it was not seated properly. Fixing that fixed the problem. The piezo can be sanded slightly if it is not perfectly level. After insuring it's slot bottom is level and of uniform depth, insure it is then seated properly before replacing the saddle. If the piezo is not otherwise faulty, this "should" fix the problem.

I'm having the same problem with a copper flexible pickup I put in a custom uke I had made. Someone on another post mentioned that some luthiers put a hole on both ends of the saddle groove and feed the pickup in one and out the other. I'm going to try that on mine.