Bass Uke pickup volume not balanced fix.

[KohanMike]

Not sure if I posted this here before, but if not, here is a fix for unbalanced volume on bass uke pickups I discovered on the Talk Bass forum that I've used a few times that works perfectly.

The pickup assembly has an inherent design flaw; the ceramic saddle (beige part) is solid even though there are slots cut in it. The metal tray it sits in has four individual pickup elements that the saddle is supposed to press against, but because the saddle is solid, it does not always put even pressure on the four pickups.

First undo the strings, then disconnect the pickup cable from the preamp by unscrewing the preamp to get to the where it's plugged in, or if you have a solid body bass, open the back plate to get to the pickup cable plug. Remove the assembly from the bridge. If you can't get to the plug, see if you can pull up the pickup assembly out of the bridge.

Next pull off the two black caps, they can be tight, and slide out the saddle. Next, I used an Xacto thin saw blade to cut apart the four sections of the saddle, you can also not cut all the way through, just be sure the cut is deep enough to be very flexible. If you cut apart the pieces, use a bit of tape on top of each cut to make it easier to put back in the metal tray. Carefully place the saddle assembly in the metal tray,. Slide in the black caps and put the assembly back in the bridge, plug it into the preamp and reset the strings, then remove the bits of tape of you used them.

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Michael Kohan in Los Angeles, Beverly Grove near the Beverly Center
8 tenor cutaway ukes, 4 acoustic bass ukes, 10 solid body bass ukes, 14 mini electric bass guitars (Total: 36)
•Donate to The Ukulele Kids Club, they provide ukuleles to children in hospital music therapy programs. www.theukc.org
•Member The CC Strummers: www.youtube.com/user/CCStrummers/video, www.facebook.com/TheCCStrummers

 

[Mickeyj4j]

How is this supposed to work I dont understand. How would cutting the bridge into seperate pieces fix any pressure on the Piezo element underneath. If the piezo and the bridge are both flat then the pressure and contact should be spread evenly over the pickup by the strings.

 

[KohanMike]

How is this supposed to work I dont understand. How would cutting the bridge into seperate pieces fit any pressure on the Piezo element underneath. If the piezo and the bridge are both flat then the pressure and contact should be spread evenly over the pickup by the strings.

It's not the bridge that gets cut, it's the saddle that's in a metal tray that presses on four separate pickup elements in the tray. Because the saddle is solid, it sometimes does not make contact with the four pickups evenly. By cutting apart the saddle, each piece makes direct contact with the one element under it via pressure from the corresponding string. The entire pickup assembly sits in the bridge. Do you have a bass uke with this kind of pickup assembly?

 

[Mickeyj4j]

It's not the bridge that gets cut, it's the saddle that's in a metal tray that presses on four separate pickup elements in the tray.

Yes That is what I meant "why does the saddle get cut"

Because the saddle is solid, it sometimes does not make contact with the four pickups evenly. By cutting apart the saddle, each piece makes direct contact with the one element under it via pressure from the corresponding string.

I can only see this being a problem if the saddle Is not totally evenly flat, or if the strings are not made with even pressure to put even pressure on the pickup.

The entire pickup assembly sits in the bridge.

yes this is how piezo rod pickups, solid or seperated ones, work on all instruments that use them. Bass/uBass, Acoustic guitar, ukulele etc.

Do you have a bass uke with this kind of pickup assembly?

I have been playing musical instruments Guitar, Ukulele Bass for over 20 years. I have a custom 5 string uBass in the process of being shipped to me at the time of writing this reply. I believe it has a single rod piezo or at least 2 4 string ones cut to make a 5 string.

 

[don_b]

Thanks for the tip, Michael!

 

[KohanMike]

I have been playing musical instruments Guitar, Ukulele Bass for over 20 years. I have a custom 5 string uBass in the process of being shipped to me at the time of writing this reply. I believe it has a single rod piezo or at least 2 4 string ones cut to make a 5 string.

Unless you have this particular pickup, you will not understand how this fix works, it's not a standard saddle. I have done this fix on six of my bass ukes, as have a number of other people. The proof is in the pudding.

 

[smartdaddy]

Not sure if I posted this here before, but if not, here is a fix for unbalanced volume on bass uke pickups I discovered on the Talk Bass forum that I've used a few times that works perfectly.

The pickup assembly has an inherent design flaw; the ceramic saddle (beige part) is solid even though there are slots cut in it. The metal tray it sits in has four individual pickup elements that the saddle is supposed to press against, but because the saddle is solid, it does not always put even pressure on the four pickups.

First undo the strings, then disconnect the pickup cable from the preamp by unscrewing the preamp to get to the where it's plugged in, or if you have a solid body bass, open the back plate to get to the pickup cable plug. Remove the assembly from the bridge. If you can't get to the plug, see if you can pull up the pickup assembly out of the bridge.

Next pull off the two black caps, they can be tight, and slide out the saddle. Next, I used an Xacto thin saw blade to cut apart the four sections of the saddle, you can also not cut all the way through, just be sure the cut is deep enough to be very flexible. If you cut apart the pieces, use a bit of tape on top of each cut to make it easier to put back in the metal tray. Carefully place the saddle assembly in the metal tray,. Slide in the black caps and put the assembly back in the bridge, plug it into the preamp and reset the strings, then remove the bits of tape of you used them.
View attachment 136140

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Michael Kohan in Los Angeles, Beverly Grove near the Beverly Center
8 tenor cutaway ukes, 4 acoustic bass ukes, 10 solid body bass ukes, 14 mini electric bass guitars (Total: 36)
•Donate to The Ukulele Kids Club, they provide ukuleles to children in hospital music therapy programs. www.theukc.org
•Member The CC Strummers: www.youtube.com/user/CCStrummers/video, www.facebook.com/TheCCStrummers

hello Uke Experts,

when I got this Ortega Lizzy bass ukulele I 1st thought I have to compensate the low volume of the E string by playing technique.
But this thread encouraged me to unmount the pickup. It was sitting in its slot quite tightly, I had to push with a small screwdriver through the whole for the pickup wire to get it moved. On the photo you can see it looks quite like the one posted by KohanMike.

As you can see as well I did not put the strings off, just tuned them real down so they dont sound anymore.

I decided not to cut anything into pieces but instead used a fine sandpaper and polished the areas for the d and a string, really just a little bit. Once I had some dust on my finger I stoppped and mounted it together again.

And see and hear: i got just the balance I wanted. Actually I am not sure the sandpaper action was causing the effect. maybe it was just the unmount and proper remount. I will never know.

Remark: please take care when re-inserting the light brown bridge part: it is not symmetric:

• the swinging part of the G string is supposed to be shorter than the E string
• the height for the G string is lower than for the E-string.

Question: from what I saw there are actually four pieco segements within the metal frame. If they could be electrically connected separately rather than having them all in parallel they could be wired to a simple 4-channel-preamp allowing to tune the balance electrically. I would try that if I had the corrrect pickup replacement part at hand. Does anybody know where to get exactly these ?

happy playing !

 

[KohanMike]

Question: from what I saw there are actually four pieco segements within the metal frame. If they could be electrically connected separately rather than having them all in parallel they could be wired to a simple 4-channel-preamp allowing to tune the balance electrically. I would try that if I had the corrrect pickup replacement part at hand. Does anybody know where to get exactly these ?

happy playing !

As I mentioned, I did the fix I described to a good number of my bass ukes, which worked perfectly. I don't see a need to rewire the individual pickup elements and try to find a preamp with four inputs. In my opinion, you're over thinking it. Cut apart the saddle and you'll never have to deal with it again.

 

[smartdaddy]

As I mentioned, I did the fix I described to a good number of my bass ukes, which worked perfectly. I don't see a need to rewire the individual pickup elements and try to find a preamp with four inputs. In my opinion, you're over thinking it. Cut apart the saddle and you'll never have to deal with it again.

Hi , thanks for the info
on the pickup i disassembled the rectangular area per string where the beige part of the bridge actually is in mechanical contact with the piezo is quite small. So I would not be surprised if,as some have reported here, that does not end up with a perfectly fixed position for each of the bridges parts, if i split it up into pieces.

Maybe there are different arrays of piecos around ? If the piecos on my pickup were bigger in comparison to the space inbetween i would probably try the spilt-bridge-approach.

 

[smartdaddy]

I actually found a pickup on the elecric bay from a shop called sportsmall2017 for 7.30€
The photo looks quite close to my ukes pickup.

And a piezo is a piezo which means it should cost a few cents. As long as they choose real solid plastic for the bridge and soldered the wire correctly it would work.

Of course it is from china ...
... I will report once I have it in my hands

 

[turf3]

The fit of the saddle in the slot is also important. It should be a very accurate slip fit, NOT a press fit. If the saddle can't move up and down it won't transmit string vibrations to the piezo sensor under it.

I have seen single piece saddles with four raised areas to push on the piezo elements, but unless every item in the assembly is very accurate, you're still depending on the flexure of the saddle up and down, which is the direction in which it's stiffest. Either cutting the saddle into four separate pieces, or (which I think I would vote for) cutting it down leaving only 1 mm or so to join the 4 pieces, will ensure that each piezo elements is receiving force from the string above it, not hampered either by friction of the saddle against the sides of the slot (see my first paragraph) or the greater heights of the saddle-piezo-support-bridge slot bottom on either side of it.