Sobers wrote: ↑
Tue Mar 27, 2018 9:15 am
Thank you Jack, for your insightful post on this subject. I would like to hear your instrument.. please send me a link or share it here.
I have few questions though:
1) What is your scale length on the 7th, 8th and the 9th string. Are they like normal CG machine heads or attached separately? (though you have mentioned but a pic would be helpful)
2) What is the thickness of the wood you've used? (all I mean)
3) Any distinct bracing patterns to enhance the bass sounds?
Sorry Sobers, haven't been here for a year! But I answer your questions:
9th string length: 72 c / diameter: .075"
8th string 70.5c / .052"
7th string 69c / .041"
These are relatively floppy: the top of my guitar is somewhat underbuilt, and if I put heavier gauge strings
the bridge sinks down... the guitar sounds gorgeous but I have had a hard time adjusting the action, string tension
and intonation - 3 mutually dependent variables since the action varies slightly with the string tension. This can be remedied no
doubt on the "next build" but this guitar is pretty nice and I am in no hurry for another one. I have been playing it for three years now.
I bought individual Schertler tuners from Stew Mac. They are very nice tuners; I think they are 18:1.
I had to buy two complete sets, so I had three left over.
See the pics on the other thread, entitled something like "Brahms guitar specs".
The bracing pattern is a lattice. There is a pic on the other thread. There is no special bracing to enhance the bass.
The low F#1 does not sound too thrilling by itself, but it is very very useful and sounds fine under other chords.
To improve it might require a larger body and a longer string. Meh.
However, a design flaw did emerge which could be corrected in another build. This was unanticipated, though I could say "duh" after the fact.
The angled bridge under tension rolls directly toward the nut parallel to the strings. It does not roll perpendicular to its own angle, it
follows the pull of the strings directly. This means that the point of the angled bridge, where the A4 string is attached,
digs into the top and makes a dimple. Now, the lattice brace system is designed symmetrically as though the greatest downward
force and rolling-forward force is centered - but in fact the force is not centered, but drives down at the angled point of the
bridge on the treble side. This point of force occurs off to one side of the lattice, where it starts to thin out; the lattice
does not connect all the way to the sidewalls, so there is a small area of un-reinforced top all around the edges of it.
This results in the treble action sinking down variably as mentioned above; since it doesn't sink down all at once, but over a period
of a week or two after being strung up, I have had to build several different saddles to get it right, and in fact I still don't have
it quite right, I am getting a few zingy notes on the A4 and E4 strings, but it's still an experiment in progress.
The two obvious corrections are (1) beef up the bracing under that pointed end of the bridge, or (2) use a floating tailpiece as in Galbraith's design.
I can't tell you about the thickness of the wood. I didn't build it myself: I had it built to my specs. This is the second one.
The first one was overbuilt. The second one is underbuilt, but it sounds better. I may play it for a long time; I don't play any
other guitars and I really love this one in spite of the fact that, being still an experimental instrument, there could be
some improvements. Somebody wants to give me 50 thousand monetary units of some sort to play with, I will have a state
of the art one built after another prototype or two.