So, as I posted in Wyodeb's thread, I've got a D-03-12 that I really like.  Except that I've been having issues with it since it was set up a couple of months ago.  I bought it last June and took it in for a warranty set-up in March, because the action was starting to feel a little high.  When it came back, it felt OK at first, but it quickly became clear that whatever they did, they went too far.  It now routinely buzzes on the second fret of the bottom two courses, and the bass tone is now anything but robust -- almost pallid.  The tone overall has acquired a tinny edge that I don't much like and is definitely not the way the guitar used to sound.

I changed the strings to D'Addarios, which made a small difference, but not enough. 

What do the experts think?  Does this sound like a neck-relief issue?  Should I go back and demand a more careful set-up?

It sounds like the saddle was lowered a bit. One of the risks in doing so is that you won't be able to dig in to the strings as much, if the action is really low. depends on your playing style of course.

You're probably going to be in for a new saddle is my guess, assuming that judicious use of the truss rod  isn't going to help.

Thanks Randy.  If they did lower the saddle, there's going to be hell to pay, because I did not ask for that.

But maybe a new saddle is a good idea any way.  I'll go check and see if Colosi does 12-strings.

The hardest part of a setup is the unknown once it leaves the shop.Check the relief to be sure you haven't moved,loss of bass responce sometime has to do with humity it have been different in the shop compared to home.

Thanks UnclRob.  Checking the relief is unfortunately not something I trust myself to do.  I might try a tiny turn of the truss rod (something I've never done before) but ultimately I think it may have to go back into the shop.

the saddle height, nut slot cut depth, and truss rod all work together to achieve action nirvana.  ask them what they did.  if you should happen to go with a new saddle, label and keep the old one around just in case.  If you find another twelve string in the shop that gets it right, simply tell them to "make it like this" and they can be more objective. 

Well...I just threw caution to the wind and did a truss rod adjustment for the first time in my life.  I used frets.com and a Dan Erlewine book I have as my guides.  (I didn't think I'd ever find the rod, but the tool that comes with the guitar turns out to do a pretty good job of guiding you to it). 

I figured the problem was too little relief, so I loosened it.  I tried to be very conservative, adjusting it in little increments at a time.  I've got it to where it sounds pretty good; there's still a little bit of buzz, but not as much as before, and the bass tone is quite a bit better.  I figure I can live with that until the next pro set-up.

Thank you sincerely to the whole Larrivee forum.  I don't think I would have had the confidence to try this without this place.

Congrats on your first step's.Overcoming the fear to make minor adjustments is a wonderful thing. :GRN>

one possibility is humidity.

Andy