acccording to Hans' book, the D-40 has a 3-piece mahogany/maple neck, and the D-35 has an all-mahogony (1-piece?) neck.
Just expanding on a good start:
Only early production had 3-piece necks, don't remember exactly when they went to 1-pc, but I think it was done by the mid '70's.. (Isn't it in the book? Then maybe it was later..)
The D-35 would also have dark tourtoise shell or black binding, where the D-40, as Neal stated would be white/iveroid binding. Hans' book also references a 5-inch body depth for the D-40; and 4 7/8-inch body depth for the D-35, but there may be some variation here (I would not not buy one or the other based on body depth alone, at least not without playing it first...)
In fact Hans has explained before that there was a potential for as much as a 1/2" of variance even in the same model because of how the bodies were built. "IIRC", it was because the bucks for setting up the sides weren't all precisely the same height and the variation occurred when the rims were sanded in preparation for putting on the top. I seem to recall that in fact they didn't overcome that problem until New Hartford
If one guitar was 1/4" over spec and one was a 1/4" under, presto, you've got 1/2" variation between two samples of the same model, although that would be pretty extreme.
But an 1/8" of variance in depth is really more like "standard production tolerance", "LOL!" :wink:
The D-35 has a silkscreen headstock logo and black binding front and back, while the D-40 has the MOP Chesterfield headstock inlay and
I seem to recall it was mentioned very recently, D40's didn't actually get a chesterfield until mid-67.
There may be some bracing differences, but I'm not sure about that.
I think that might be the most likely explanation for any sonic differencesbetween D35/D40, but I've never seen specs for either one and they may have changed over time anyway.
Wouldn't the D40 have had higher grade tone woods?
I'd be kind of surprised, also, what literature I have seen (and that's NOT a whole lot, but maybe somebody else has lit), only ever references if the top wood was an upgrade to AAA from their everyday sitka. Quality of woods of backs/sides was never shown, that I've seen.
Even for the flagship D55 and later D100, it would seem to make sense that they'd select best available woods in inventory for those guitars, but I've never seen a flat-out confirmation of that. I doubt that they'd have bothered to select for woods between for D40's and D35's but that's just based on what I've read here over the years.
From another angle, they probably already had relatively (for the time) high grade woods in inventory anyway and didn't really need to select. It's been mentioned before that Guild had some pretty discriminating graders.
Over the years we've seen other changes in "formula" that I've only seen documented here, such as bracing changes, or thinner or thicker backs/sides/ tops. Running production changes and even things like bracing specs weren't always published and so there're a bunch of unknown variables between production eras and models and they can add up to noticable differences in sound quality.
The D-35, or some of them, have a different (smaller) pickguard. some Guilds can maybe be considered the "evil twin" of other Guilds. perhaps the D-35 is one of them. I used to think a solid/flat backed, spruce topped D-25 was a rare bird, until I realized that would essentialy make it a D-35 or a D-40 (making it is about as rare as sand in a desert)
What I can't see from here where I post is whether or not the D35 was introduced at a time when the D40 was in "hiatus". (Han's book is at home, I'm not), that might explain why the specs are so close to the D40's. For instance, the D40 was in hiatus during the mid-90's when the DV6 was filling the slot of the flatback 'hog body dread.
Or it could just have been one of those situations where a viable niche was seen for a slightly "de-blinged" D40, just like that pair of "evil twins", the D25 and the D4.
:wink: