PDA

View Full Version : Kala U bass Sub4fs pickup's



shortcircuit
12-09-2015, 03:12 AM
The "D&G" string are very low in volume. Have to turn amp up to use, but then the E&A string are very loud. Would this be normal for this uke? Any adjustments? Or mybe should I upgrade the pickup and/ electronics

shortcircuit
12-09-2015, 03:22 AM
I see some have changed the pre amp out for a LR Baggs. I wounder if that will fix my problem.

Booli
12-09-2015, 05:36 AM
I see some have changed the pre amp out for a LR Baggs. I wounder if that will fix my problem.

I had a similar problem on my Rondo Hadean solid-body uke-bass, which is a cheap $150 copy of the Kala Sub U-bass, and was able to remedy as per below.

Uneven volume is usually likely due to uneven pressure upon the pickup element from the saddle.

Before making any cash investment, it might be worth your time to remove the strings, and inspect the underside of the saddle and see how it is making contact with the pickup element.

After that you might also want to inspect the saddle slot, and make sure that it is perfectly flat, so that the pickup element is ALSO laying on top of it perfectly flat, as any interference in this will effect the way that the strings apply pressure to the saddle, as well as apply pressure to the piezo pickup element.

Aside from a flat surface, if the saddle slot is uneven it it's width of the cutout, and binding the vibration of the saddle, even by 1/64", it can be pinching the saddle in place and not allowing it to seat all the way down onto the pickup element, and therefore not transmitting all of the string energy. The saddle needs to vibrate freely, but not wobble in the slot, and the tolerances are pretty small for this.

To remedy this you can use some sandpaper to either gently widen the saddle slot in the effected area, or gently take a hair thin amount of material off the saddle itself, which in either case, I would do towards the butt-end-side, and not the nut-side of the saddle, otherwise it may effect your intonation to go sharp too much.

If you do this, go slow, as there is no going back without replacing the parts that have too much material taken off.

It's not a complicated task, but requires a gentle touch with some finesse in order to not go too far.

In my case I opted to sand down the butt-end of the saddle where it passes over the D and G strings, and this fixed the problem.

Prior to doing so, I wanted to verify that it was not the pickup element or the preamp that was either defective or had some odd frequency-boost that neglected the range of the D and G notes.

At first I opened the electronics cavity and unplugged the pickup element from the preamp and use alligator clips to connect it directly to a guitar cable and run that straight into my amplifier, and the problem was still present, so that told me that at least the preamp was not the cause.

Next I replaced the pickup element with another similar to the LR Baggs silver piezo ribbon, and also ran it direct to the amp with alligator clips, and STILL had the problem.

So then I inspected both the saddle and the saddle slot width with a pair of precision digital calipers, and found that the molded plastic saddle was in fact not even across it's width. I used 50 grit aluminum oxide sandpaper (very course) and with about 8 strokes across the area for the D and G strings, on the end of the saddle facing the endpin, took off about 1/64" of material, on the BROWN plastic part, that holds the white plastic saddles - NOTE THAT I did NOT sand the white plastic saddles at ALL.

After putting it all back together like it was originally from the factory, the volume output is now even across all 4 strings.

This may or may not work for you, so proceed at your own risk and only if you are confident in doing so.

I know that if I went to far, I'd either have to make a new saddle or bridge, or source the parts online either from Kala or from another vendor. I was willing to accept this risk.

Please let me know if this information helps you. :)

shortcircuit
12-09-2015, 06:44 AM
Booli, I will look into this tonight when I get home. Let you know what I come up with. Thanks

shortcircuit
12-10-2015, 08:32 AM
Did pull the under saddle pickup out last night. Cleaned up and made sure it was flat. Reassembled. Still same. Maybe tonight I will try one of those cheap guitar saddle pickups and see if the same.

shortcircuit
12-12-2015, 02:12 PM
Found a bad solder joint. Seems to have fixed the problem. Will have to play it more to be sure. But for now, ok

Patrick Madsen
12-12-2015, 03:02 PM
Glad to hear it's better. A preamp sure changed my bass into a sound monster. It also cleans up the sound on my tenor with a Misi.

shortcircuit
12-13-2015, 09:17 AM
Thats what I was thinking from the beginning. I was looking to see if any had changed the preamp, and what make and modle did they use.