Author Topic: Truss Rod vs Bridge/Nut Adjustment (Read 2155 times)

kayo · « **on:** October 21, 2004, 03:12:29 PM »

I am hoping that those of you with more expertise than I can help me decipher what my problem is....

I have been having an increasing fret buzz problem.... My question is, how do I know when what I need to do is adjust a truss rod vs raise the saddle on the bridge or a nut adjustment?

I have a Rogue 4 string fretted, and have been using the same brand of strings for at least a year now (DR High Beams) and about 4 months ago this buzz started on the G string first, then the D string. It begins around the 4/5th fret and runs pretty much down the length of the neck.

Any / all help would be greatly appreciated.

David Houck · « **Reply #1 on:** October 21, 2004, 03:28:13 PM »

Since you haven't changed the brand of strings, and since all was fine until a few months ago, my guess is that a change in humidity has moved the neck some and you need to adjust the truss rods.

Generally, you adjust the nut for first fret buzzing, not for buzzing further down the neck.

If the buzzing was only on the frets nearest the pickups, then adjusting the bridge would be appropriate. But for buzzing that starts at the fifth fret and runs the length of the neck, it sounds to me like a truss rod adjustment.

palembic · « **Reply #2 on:** October 21, 2004, 03:35:56 PM »

Brother Joey is the expert in this.
I think that if the buzz is on the first 3 frets work on the nut, is the buzz on the upper half of the neck, work on the truss rods, if the buzz is on the lower half of the neck, work on the bridge.
Now that is FAAAAAAAAAAAAAAAAR too simple but basically it IS true.
Of what I can mek up from your text it is a truss rod adjustment, that you'll have to fine-tune with the bridge.
Do a search for the Joey Routine. He wrote a step-by-step (must copy) threat somewhere. IMPORTANT: do it in eeny-teeny bits of turns and WAIT ..wait ...be patient ...after every step you make. Let the bass TIME to respond to your changes.

Some ideas

Paul the bad one

lbpesq · « **Reply #3 on:** October 21, 2004, 03:45:33 PM »

Just curious. Other than a buzz on an open string, why would a nut adjustment have any effect at all on a string that is being fretted? (unless you're Eddie Van Halen)

Bill, the guitar one

(Message edited by lbpesq on October 21, 2004)

811952 · « **Reply #4 on:** October 21, 2004, 04:00:53 PM »

Sounds to me like you've got 2 problems. If it's not buzzing on the first 4 frets, you may be able to actually lower the nut a smidge in addition to adjusting the bridge and/or truss rods. Hold the string down on the first and last frets and see if you've got any bow in the neck or not. You want to have just a little (16th of an inch or so at the middle if holding down the first and last frets). Som people like more and some like less depending upon how they play. When you've got the neck where you want it, you can lower the nut to where the clearance over the first fret is the same as the clearance over the second fret when fretting the first fret and you should be good to go. It's something to play with, since we have the unique ability to, ahem, adjust our nuts non-destructively. And look for Joey's treatise on adjusting your neck, because if I recall it covers all of this in great detail and better accuracy...
John

kayo · « **Reply #5 on:** October 21, 2004, 04:24:09 PM »

Dave, Paul (TBO) & John

This is great - just the feedback I was looking for. I'll start the adjustments over the weekend and hopfully have a results oriented post next week to say that the problem is solved!

Cheers

bigredbass · « **Reply #6 on:** October 21, 2004, 10:37:24 PM »

Kayo

The greatest thing about ALEMBICs is the adjustability built into them vis-a-vis playing action. The double truss rods (uncommon) and the adjustable nut (VERY uncommon) and the bridge (already cast in the curve to match your fingerboard radius) form the PERFECT platform to experiment and learn to adjust your action yourself. There's no neck to unbolt, no plastic nut to file or fill in, etc.

Do two things FIRST:

-If the budget permits, put on new strings, the kind you always use

-After they are through stretching, BE SURE you are tuned up

Old strings can cause their own problems: New string will eliminate these right off the bat.

Tuning equals tension: If you're sharp, the neck will be under more tension; flat, there's not the correct tension, so get your tuning straight FIRST.

The short setup recipe is this, and do ALL of the following with the bass in playing position in your lap, NOT LAYING ON ITS BACK ON A TABLE!!

F I R S T

The nut height needs to be at a point where it's high enough so when you fret a note at the third fret (G on the big E, for example), reach around
with your other hand and press the string against the first fret while still holding the note at the third fret. It should have just a tiny bit of room to move down and you should hear a little 'clink' as it hits the fret. If it's already touching, raise it SLIGHTLY and try again. A LOT of clearance? Lower is slightly.

With the ALEMBIC nut you'll need to detune to loosen the lock screw, then tune up and work through this. All the strings' clearance should end up about the same clearance. Then lock your nut and you're through at this end. Re-tune.

SECOND

Are you in tune? Now the truss rods. Find a medium pick. Hold the E down at the first fret.
Capo (or get a third hand/wife/brother/kid ...) the same string down where it meets the body.
The pick should just slip beneath the string at the fret halfway between the two hold-down points. Won't fit? Loosen the truss rod on that side SLIGHTLY (a half-turn on a truss rod is a BUNCH, so just go in tiny fractions of a turn!) till it will. Fits between the string and fret with room to spare? Tighten it just a bit. The ideal fit is it laying on the fret and displacing the string upward ever so slightly.

Done? Re-tune, and repeat the process on the G side using that truss rod. Finished? Re-tune.

THIRD

Are you in tune?
We'll set the string heights over the end of the fingerboard AFTER the nut and truss rods are done. You'll adjust the E side by using the allen wrench to raise or lower the bridge on that side. Adjust to where the bottom of the string is about 3/16 over the 24th fret, with the string not fretted or pressed down. Re-tune. Do the same thing on the G side, but adjust it to about 1/8 clearance between the bottom of the open G string and the top of the 24th fret. Re-tune.

This is a 'general' setup to get you to a repeatable set of dimensions. Your hands will tell you if it's too high or low, and the neck will tell you if it's too straight or if you need to let a little more bow back in. No two basses will adjust identically, because wood is never identical.

Over time, you will learn to get YOUR bass just like YOU want it completely on your own. This is the genius of these instruments.

Remember: Neck adjustments are in TINY movements. Think watchmaking, not bridge-building. ALL of us have turned our basses into boat oars the first time or two till we 'got it'.

Don't be surprised if you have to 'touch up' this adjustment the next day, it sometimes takes a day or two for everything to settle in.

Best of Luck,

J o e y

palembic · « **Reply #7 on:** October 21, 2004, 11:02:16 PM »

Rrrrrrrrrrufl ...et voil? ...the master himself.

Bro's and sis's ...start your printers!!!

PTBO

bob · « **Reply #8 on:** October 22, 2004, 12:34:50 AM »

Joey, you're still getting better at explaining this - a few more times, maybe we can get it printed on a wallet sized reference card.

811952 · « **Reply #9 on:** October 22, 2004, 08:51:47 AM »

Joey,
I'm gonna send you a list of things I need to have explained to me...
John

kayo · « **Reply #10 on:** October 22, 2004, 09:14:06 AM »

Joey -

What a great post!!! Many many thanks. I was a bit embarrassed to ask this question - everyone here is so knowledgeable..... I do know a few things, but Alembic is such a fine instrument I am intimidated to do these things - but at the same time can't afford a pro to do it for me, and am not sure I would want anyone else messing around with my baby either.

I did want to ask one thing..... which way do I turn the truss rod to loosen? Am I correct that tightening would be clockwise?

Again, I thank you.

Cheers!

David Houck · « **Reply #11 on:** October 22, 2004, 09:26:35 AM »

From the owner's manual:
If you want to increase forward bow, turn the nut counterclockwise.
So, you are correct, tightening would be clockwise.

bigredbass · « **Reply #12 on:** October 22, 2004, 10:48:47 PM »

Kayo

You're welcome!

Remember the old shade tree mechanic's mantra:
Righty-tighty, lefty-loosey (think 'waxon, waxoff. . .').

I'll recommend Dan Erlwine's fabulous book,
The Guitar Player Repair Guide (isbn 0-87930-291-7) available at most bookstores. This is where I learned EVERYTHING I told you.

I can't help but to repeat what a fabulous 'laboratory' ALEMBICs are to teach yourself adjustments. On a Fender, you'd have a nut that could only be filed deeper, or would have to be built up with glue and HotShot to raise the nut heights. You'd have to unbolt the neck to get at the single truss rod, and getting it back in EXACTLY the same position would be impossible with wood screws. The bridge would have two legs per saddle per string to arch your strings to match the curve of the fingerboard.

As you can see, ALEMBIC's feature set reduces all of these parameters to easily adjustable mechanisms. You have the luxury of trying the nut at different heights. The bridge already matches the fingerboard radius. TWO truss rods allow essentially separate adjustment for both sides of the neck: Maybe not a big deal on a four, but a BIG help on my five string in fighting that big B separately from the little G.
And above all else, laminated neck thrus pit the string pull against the length of the instrument instead of mostly the neck: They are always more stable than a bolt or set neck instrument.

But PLEASE remember to do these adjustments in TINY increments until you see the light. Big adjustments are hard for your brain to assimilate at first, and can possibly damage your instrument if you're hopelessly ham-fisted. And once you arrive at 'your setup, tiny instruments are all you'll occasionally need.

I did not want to take my bass to a tech, because there are lots of great guitar guys that give bass the bum's rush. I knew no more than you know now, probably less. But after lots of reading, experimenting, and wondering if I'd ever get my ALEMBIC to play right again, I 'got it' and am very satisfied that I can maintain the feel I want regardless of climate, style, or different strings. And so will you.

But it is really only a testament to the Wickershams' genius in the genesis of these instruments. And their big enough hearts to think we could participate in our own maintenance. What a concept!!

Best Wishes,

J o e y

PS: Bob, aren't fretless fingerboards set dead-straight?

bob · « **Reply #13 on:** October 22, 2004, 11:53:48 PM »

aren't fretless fingerboards set dead-straight?

Well, that's what they say....

If you're asking about mine personally, I tried it and it didn't suit me. I've settled in around .009 on the B, .006 on the G (in inches, measured at the 7th 'fret' while holding down the string at the 1st and 24th).

In tune, and in playing position, of course :-)

bigredbass · « **Reply #14 on:** October 23, 2004, 11:00:58 AM »

Never having played fretless, I had heard that several places. But the string is still vibrating in its arc. I felt like eliminating the frets would give some elbow room, but that a 'dead straight' fingerboard would have had to have been between a really high nut and bridge.

Thanks for confirming my suspicion.

J o e y