Official Luthiers Forum!
http://www.luthiersforum.com/forum/

U-bass set-up
http://www.luthiersforum.com/forum/viewtopic.php?f=10128&t=47544
Page 1 of 1

Author:  unkabob [ Wed Mar 30, 2016 8:58 am ]
Post subject:  U-bass set-up

I am looking for the clearance of the strings above the fret twelve on a U-bass. This is the middle of the scale and should have the greatest displacement. With the soft, fat strings at low tension I expect some real movement on the strings and would prefer to have a target to move down toward.

Any help would be appreciated.

Bob :ugeek:

Author:  UKSteve [ Wed Mar 30, 2016 10:38 am ]
Post subject:  Re: U-bass set-up

Watching this post with interest, Bob. Vital info for me too.

Wish I'd taken more notice of the one I handled now idunno

Author:  Hesh [ Wed Mar 30, 2016 2:58 pm ]
Post subject:  Re: U-bass set-up

There is no hard spec for any set-up of virtually any plucked stringed instrument without also being a function of other variables such as:

1) Nut slots
2) relief
3) tunings
4) flexibility of the strings
5) quality of the fret plane, fret work

As such my suggestion and my approach would be to do the following in the following order:

1) set the relief, more on the low bass side and less on the treble side
2) cut the nut slots properly and low
3) do the math to make a dummy saddle or three out of any old scrap, wood is fine for this
4) Try it at 5/64th" for the smallest string (highest pitch) and 7/64" for the largest, lowest string.
5) play it and evaluate and adjust accordingly

If it can do 5/7 which is a pretty standard "low action" spec for bass guitars and you want the action lower then employ the dummy saddles and see how low you can go without buzzing out. It's the sneak up on it approach so-to-speak.

U-basses are not common out here and the commercial implementations had and has issues in our experience with the UST and uneven output balance. With this said break angles over the saddle are sensitive with these plastic strings and lowering the saddle. Decreasing break angles may get you lower action but it also may impact the balance and output of the UST.

I seriously doubt that the retailers who sell U-basses do any set-up at all. With this said it's likely that what we see set-up spec wise from the f*ctory may be what the manufacturer has found sucks the least with the uneven output issue common to this instruments.

Bob you may be on the bleeding edge here and have to do some testing yourself to see what works best with the UST that you are employing and then report back.

Author:  Allen McFarlen [ Thu Mar 31, 2016 11:15 pm ]
Post subject:  Re: U-bass set-up

1/4" if you are using the polyurethane strings. It sound like a lot, but they are so soft and rubbery that it's no worries at all.

Author:  UKSteve [ Thu Mar 31, 2016 11:26 pm ]
Post subject:  Re: U-bass set-up

Cheers Allen

Is this a measurement of a factory instrument or your setup number?

Steve.

Author:  Allen McFarlen [ Sat Apr 02, 2016 2:22 am ]
Post subject:  Re: U-bass set-up

I asked Owen at Road Toad about set up for some I was building. That was his recommendation and it worked for me.

Author:  UKSteve [ Sat Apr 02, 2016 3:49 am ]
Post subject:  Re: U-bass set-up

Great, thanks mate.

Author:  unkabob [ Sat Apr 02, 2016 10:58 am ]
Post subject:  Re: U-bass set-up

Thanks for the information.
I am around 0.200" max and ready to string it up after I see the video on www.goldtone.com . Until I have tension on the strings, I can't measure height accurately. These are Goldtone strings using a 23" scale. The under-saddle-piezo gives me a wedgie-shaped saddle which seems strange.

More news tomorrow, I hope.

Bob :ugeek:

Author:  unkabob [ Sat Apr 02, 2016 1:55 pm ]
Post subject:  Re: U-bass set-up

I understand why these tuners were replaced. The factory probably used large-slot screw-on string inserts for three of the four inserts. Keeping the strings in place while tightening appears to require at least three hands. I have set this job aside for another day to avoid a temper tantrum.

Bob :ugeek:

Author:  unkabob [ Sun Apr 10, 2016 11:00 am ]
Post subject:  Re: U-bass set-up

To down-size the slots in the tuner-caps, I used JB Weld in the slots and string ends in saran-wrap. It took two tries to get things snug.

I found that when the strings tightened up, the tension of the strings unscrewed the caps. I solved that with blue Locktite.

The string-ends tended to squirm out of the slots under tension and pulled out over a ten minute period. I left the strings in the slots over-night (cool-down time) intending to put a drop of CA to hold the string ends in place but the next morning everything tightened up without the glue. I suspect that the soft strings may have conformed to the surface of the slots to hold on.

The next challenge is to wire up an amplifier connection through a 1/8" stereo plug. A 1/4" to 1/8" stereo adapter doesn't work with a standard guitar chord. I have guitar plugs on order.

Bob :ugeek:

Author:  UKSteve [ Tue May 24, 2016 3:32 am ]
Post subject:  Re: U-bass set-up

I got mine strung up over the weekend an was having similar problems to you, Bob. The slots in the machines were a little larger than the strings I have. My short term solution was to use tie wraps (zip ties?) on the strings so they can't squirm free. It's been in tune for a couple of days now and it giving me plenty of grin factor when playing it, or trying to..:)

Image

Image

Author:  unkabob [ Tue May 24, 2016 8:49 pm ]
Post subject:  Re: U-bass set-up

Steve:
You have the newer, better tuners. I your the instrument. How does it sound through an amplifier? Are your strings white or ivory and what is your scale-length.
I used the ivory strings with a scale of 23". My cedar top gives a nice tone for practicing but is too quiet for a group of three guitars.
After chasing electronic output for a full day, I found that I had not fully plugged the piezo into the electronics box but it sounds good now.
Pictures will eventually come. I would like to thank Hesh for his comments, they were very helpful.

Bob :ugeek:

Author:  UKSteve [ Tue May 24, 2016 11:28 pm ]
Post subject:  Re: U-bass set-up

Hi Bob

Thanks, yes I have the ivory strings and also a 23 inch scale. 5mm gap at the 12th fret.

It's Brazilian mahogany recycled from an old window frame. Unplugged it's fine for practicing but drowned out by a guitar. Plugged in, now it's difficult for me to give a valid answer here, I only have a small guitar practice amp so I need to get my hands on a bass amp. Through the practice amp it sounds OK with a bit of a balance issue - E, A and D strings all fairly well balanced but the G seems low on volume.

I haven't spent a lot of time fiddling with the EQ etc. So it could just be me.

Overall I'm very happy with it.

Looking forward to seeing yours, Bob.

Page 1 of 1 All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/