Author Topic: Sharp Phenomenon? (Read 659 times)

dadabass2001 · « **Reply #15 on:** October 22, 2004, 05:08:11 AM »

I have seen similar tuning variances with all three of my basses. For what it's worth, I usually try to deliberately slide my hands over the strings repeatedly (bare hands or polishing cloth) after I take my basses out of the case and before I tune, specifically to deal with the warm string / cold string comparison. I'm basically pre-warming the string by friction before I start to play.
Mike

811952 · « **Reply #16 on:** October 22, 2004, 09:03:28 AM »

Joey,
I don't recall what radio station carries NPR in Nashville, but I recommend finding out when Car Talk runs and calling in with your question. If for no other reason than I'd like to hear what they'd have to say, since it is a puzzler if ever there was one...

http://www.cartalk.com/
John

pookeymp · « **Reply #17 on:** October 22, 2004, 09:26:52 AM »

Hey Joey,

This has baffled me for some time, because as yourself, I imagined that I would be tuning up instead of tuning down. But, with my Tobias, I regularly find the same thing. But, not the case with my other bassses...which are all kept in the same room.

Mikey/

bigredbass · « **Reply #18 on:** October 22, 2004, 11:46:10 AM »

And the puzzle continues:

Bob,

--- there's no binding in the slots

--- I have a light touch with both hands

--- Boomer 5string mediums (45,65,85, 105, 130)

Adriaan,

--- they are always in their case on their side,
never flat on their backs

--- the truss rods are steady, since I'm so
fussy about setUp, and you can see I'm using
larger strings

DaDA, I tune them when I first pick them up, before body heat would do anything. I don't find them uptuned (have I invented a word?) till I go to play them again a day or two later.

Pookey, have we been targeted by the same Black Project?

J o e y

bsee · « **Reply #19 on:** October 22, 2004, 12:00:36 PM »

I think you need to order some new bass cases. Yours have been infested by gnomes of some sort, or maybe pixies. On further reflection, gnomes generally prefer tuning flat, or alternating one string sharp and the next flat so you get really confused, so it's probably just pixies.

jet_powers · « **Reply #20 on:** October 22, 2004, 01:27:31 PM »

Gnome infested cases? Possibly....

I'm no physicist but, when it cools overnight as I'm guessing it does where you live, as where I do, things tend to contract. If I had to guess, and I certainly am, I would wager that the neck of a bass guitar contracting would cause the strings to tighten, and the next time you play it it would be slightly sharp. I've noticed it with my 4 strings. My Rogue 5 OTOH could probably withstand a night in the back of my car in sub freezing temperatures and still be in tune the day.

Do these gnomes and pixies have any particular color prefences for the fuzzy stuff inside the case?

John Paul

jagerphan84 · « **Reply #21 on:** October 22, 2004, 01:40:51 PM »

I'm no physicist either, but if the wood neck is contracting, wouldn't the metal strings do the same thing, but at a faster rate? Digging around my brain for the things I learned in high school, I thought metal would have a lower specific heat than wood and would therefore react more quickly to a change in temperature. If the strings contracted more then the neck, perhaps that could cause increased string tension and a subsequently higher pitch.

Like I said, I'm no physicist, so maybe you should pick up a can of gnome repellant, too.

bsee · « **Reply #22 on:** October 22, 2004, 02:02:07 PM »

Regardless of which contracts more, there would be a limit. If you had to tighten the strings every day, well, increasing neck bow or string stretch could keep you doing that for a while, but not eternally. A need to loosen the strings every few days would mean that the strings are contracting or the neck is stretching. Again, this should hit a steady state at some point. It physically cannot go on forever. If it isn't gnomes or pixies, then there's some subliminal string tightening, or maybe the tuners all hit the case just right to knock them out of tune in the same direction. Would you consider leaving the bass on its stand a few days to see if the phenomenon ceases? Note that this would also keep it out of reach of the pixies, so you still might have a bit more investigation to do afterwards.

811952 · « **Reply #23 on:** October 23, 2004, 11:25:22 AM »

Maybe you should calibrate your tuner. You might actually be playing the better part of an octave flat by now (which would explain why the band keeps changing the keys from day to day on you)...
john

bigredbass · « **Reply #24 on:** October 23, 2004, 11:26:45 AM »

Think of it though:

If the neck contracts, the bridge would walk towards the nut, and tension would decrease: Tension is tuning, so it would flat.

But, all of you made me think this through (just what I wanted you to do) and I think I've got it.

I always tune UP to pitch.

If I go past, I'll detune 'under' the note and try again, coming up and stopping on 'the spot'.

The ALEMBIC has the typical GB Gotohs. The Yamaha has their open gear tuners with the tension collar adjustment, same sort of friction control as a sealed key. As part of my setup, I run this friction rather snug, so as never to leave enough slack for them to ease off flat while I'm playing.

See where I'm going?

I'm obviously not getting ALL of the travel in the key when I come UP to pitch, and then playing in it a while 'pulls' that last bit of travel into the key and it goes sharp.

I've always set my keys this way, and every bass with adjustable keys I've owned did this.

Damn, and I was having a ball rigging the starlight scope to watch my cases for little elfin intruders . . . oh well, they're out of season anyway.

Thank you for making me work through this.

J o e y

adriaan · « **Reply #25 on:** October 23, 2004, 12:00:47 PM »

Joey,

On the regular Gotohs (as on the Yamahas, IIRC) you can insert the end of the string into the hollow centre of the tuning post. If you don't already do that ...

Adriaan

bob · « **Reply #26 on:** October 23, 2004, 01:19:24 PM »

Joey,

Maybe we should just let this be, now that you've satisfied yourself.

But I'm not quite sure I buy the 'gear slop' theory. As long as you are tuning up, the string is going to continue pulling back on one face of the gears, and I don't see any way the gears are going to sort of settle in to a middle position.

An experiment might be in order. Alternate, every other string, tuning up or down. I'd go three down, since you have more experience the other way. Check your tuning again at the end of playing, and then the next day.

My guess is you'll find the ones you tuned up are already somewhat sharp by the end of a lengthy playing session, and the ones tuned down a bit flat.

The reason I asked about nut slots is that, especially when tuning up, any friction at all is going to leave you with the portion between the nut and tuner with a little more tension than is on the rest of the string. I don't care how perfectly fitted and smooth your slots are, I'm convinced this is going to happen to some extent.

The vibrations of playing for a while would help this to equalize (sharp of your original tuning), and maybe there would be some slight creep while sitting quietly for a day (though I think this would be much less).

I also tune up, but have a regular routine where after turning the key, I press on the string between nut and tuner, probably over-equalizing it slightly, and then pull on the string (slightly harder than I would usually play) back around the pickups.

Of course, I could be wrong, or at the very least a bit obsessive...
-Bob

bigredbass · « **Reply #27 on:** October 25, 2004, 10:07:23 PM »

Bob, I've done a lot of things I'm not proud of, and I'll probably do few more to qualify myself as a dog . . . but even at that, I NEVER tune down instead of up !

I've gotta look myself in the mirror, you know?

J o e y

adriaan · « **Reply #28 on:** October 26, 2004, 02:37:43 AM »

Well, just got back from Neverneverland and what the heck - the tuning on my Spoiler had gone sharp too, after lying in its case, flat on its back for about a week (I don't play as often as I want to).

Humidity in the house has gone up over the last few days, because of the weather, and the central heating was on for the first time in months.

Duh, why didn't I check the Epic when I noticed the change on the Spoiler? Okay, will do so tonight.

adriaan · « **Reply #29 on:** November 05, 2004, 04:23:12 PM »

So it took a couple more days before I did check, but the Epic did not go as sharp. I don't have a tuner, but trust me I know when the tuning goes sharp.

It could be that neck-throughs react stronger than set-necks to - well, we haven't figured out what it was.