Eastman AR805 - neck hump
 

Just bought one off Craigslist today. Lovely! But the saddle height was maxed out - to the point of front lean. Lowered it but getting - what’s the word for the stage beyond “buzz” - thud?

I’ll bring it to my guy if I can’t pull off a DIY truss rod adjustment. To describe it generally, I’ll say it’s got a bit of a dip in the middle and (not unusual for Eastman in my experience) a hump where the neck meets the body.

Again, might not be a DIY, but how would you approach it - tighten?

Is the hump like under the neck or is there a hump in the neck itself? Hump in the neck itself could be a humidity issue and might be extremely dried out.

First thing for a DYI truss rod adjustment.
 

No, do not tighten, not yet. I would suggest that you first, measure and record the amount of up-bow at the 7th fret, then loosen the truss rod fully slack, allowing the neck to settle and relax for a short while. What you are looking for at this point is the amount of neck relief at the 7th fret with no truss rod correction.

Once the neck has settled and relaxed, you are then going to want to measure and record the amount of up-bow again. If the up-bow has gotten worse, and you gain relief, then, with some luck, you may be able to adjust this excess up-bow out by tightening the truss beyond the original setting. It would be beneficial here, to apply the augmented truss rod adjustment method, using a set of riser blocks, a straight bar and clamp to help press the neck, while tightening the truss rod. If, on the other hand, the neck relief improved, you can likely dial-in a straight neck without much difficulty.

Unfortunately, a hump in the neck at the body joint is tough to deal with. If the hump is not too dramatic, sometimes the "buzzing" frets can be dressed down so as to mitigate finger board leveling and a partial fret job. However, and usually, by the time you have removed enough material to eliminate the buzz, you have also eliminated so much of the fret crown that the string can not be played at that fret :eek:

Good luck and let us know how this issue turns out ;)

When you say neck hump at 14th fret body joint. Your really talking about the plane of the Fretboard and frets where it passes over the Dove tail joint and neck block. Quality arch tops like yours also have the elevated fingerboard wing that supports the fretboard end. If the Truss rod is over tightened creating a back bow that could create the slightly high hump on the fretboard at 14th fret area. But if the truss rod is adjusted properly and you still have the issue of a slightly high fretboard or frets in the 14th fret area. Then it is the Plane of the neck itself at the heel neck joint area. If it is minimal the frets can be pulled and fretboard re planed and re fretted. Older guitars often have this issue especially old Martins that have had neck resets over the years. Sometimes it is just a few high frets. A competent Luthier with a good straight edge fret rule should be able to diagnose what is going on. Hope you get it dialed in!!!

Thanks all, for the helpful suggestions. They made it clear that I'm not looking at a DIY fix. I'll follow up with details after I get it back from the expert.

All setup fixes are DIY fixes as far as I'm concerned. From the OP, it sounds like too much relief. It's real common to think you have a fretboard hump at the neck joint when you have too much relief, so I string it up, capo the first fret and tighten the truss rod to take out the relief measuring with a fretted string at the 14th fret. This means I'm straightening the neck between the first fret and the "hump" at the 14th fret. I take it all out, dead straight fretboard, and then look to see what neck hump remains. At this stage I can use straight edges to evaluate fret dress, and I might decide I need to dress the frets. Then, I put a tiny amount of relief back in, .005" or so, set the action at the 12th fret to .065" and see what happens. Archtops do tend to move a bit at the transition between the neck heel and the fretboard extension, so a fret dress is pretty common. So I recommend people learn how to do it themselves.

Back home from tech..
 

So, I brought the archtop home today. It's playing great now, no more buzzing.

Biggest issue was high frets, most of which were at the neck joint, but he went over the whole fretboard and leveled them. Bridge also had a loose pole, which he addressed somehow or other and recommended I upgrade the whole thing if the guitar achieves keeper status. And of course the truss rod was adjusted to remove the dip in the middle.

Thanks again for all of the suggestions and comments. Much appreciated.

Here's the AR805. It's not quite as red as it appears in the picture, but it's definitely reddish.

https://i.imgur.com/8KwGW1c.jpg

Great outcome!! Thanks for update and beautiful Axe

That's beautiful - a great find!

Just remember it is an acoustic guitar - not just a jazz guitar. Those jazz radicals have been keeping these wonderful things hidden from us cowboy chord players/singers; they want to keep them all to themselves! :D

SO many examples of the truth of that statement. This, for example;

https://www.youtube.com/watch?v=ZtldB73hiYM

OMG! That's just wonderful....

I have spent the evening jamming with a friend, working on song harmonies. For no reason other than to enjoy singing and make a big dent in a bottle of rum. I took my archtop, he had his dread - a match made in heaven. :D

Don't hesitate to contact Eastman about the bridge. They've been known to replace AR bridges, even if they are used and not covered by the original warranty. Their customer service is really good with this.

Thanks! Great idea.

Bridge hack for eastman ( or any) archtop
 

I have recently put a hybrid bridge on my AR503. This is a floating bridge type "foot" and an adjustable, metal tune-o-matic on top of it. I have Graphtec saddles on this. I notice no degradation in the sound whatsoever, and this allows me to dial in the intonation precisely, and with ease.

What I used to do on my prior archtops, is carve a new ebony bridge, with the intonation / compensation filed to the correct extent for the usual strings I am using.

The factory bridge is compensated for thinner gauge strings, assuming and un-wrapped G, so the intonation with that bridge is pretty bad, becaise the G string is compensated in the wrong direction.

I tend to use 0.012 Thomastic flats, or Pyramid flats.
Fiddling with the compensation on an ebony bridge x-piece is pretty tedious, so lately I grew tired of doing that.

The tune-o-matic brige with Graphtec graphite, or even better the Tusq saddles makes this a lot easier, so I can get the compensation/intonation prefect. I got the idea from my Ibanez archtop, which was set up this way ( floater "legs" w tune-o-matic on top). I have Tusq saddles on one of my Les Pauls. I may be imagining it, but the note separation seems to be much better with the Tusq. The guitar sounds more "hi-res" or more "articulate" if thart makes any sense. I recommend the setup. A pretty easy mod, and
with the intonation set up correctly, the guitar is magical.

Very cool. I can definitely see the appeal. If my attitude about intonation wasn't "that's close enough," I might even give it a shot.