Acoustic Slide Guitars
My acoustic slide guitars are an original design. There are currently some Chinese made Weissenborns that have copied my sound holes and head design. But as they have not copied my bracing and other acoustic innovations, they sound like Chinese Weissenborns.
Info and specs
Fret scale length - 644mm or 683mm
Nut width - 50mm (8str 60mm) - height - 13mm
String spacing - outer strings - 45mm at nut - 58mm at bridge
Top wood - WR Cedar or Blackwood
Body wood - Blackwood
Fingerboard - Blackwood inlaid into fiddleback Eucalypt
Bridge and Pickup
The spacing at the bridge is 58mm between outside strings, a good fingerpicking size. This spacing is common on classical guitars but can be altered to suit. The undersaddle pickups that I use are a low profile high output piezo version that I make myself. I charge $100 aud to supply and fit it. I do not fit preamps into the side of my guitars, as my instruments will long outlive any electronics.
The output a the piezo element is very high but if it goes into the wrong type of circuit the sound will be thin and muted. Most mixers will have this problem because they are designed for low impedance microphones. Most modern FX pedals, or signal processors use jfets or similar on the input, so using one between the guitar and the mixer is a good way to match the impedance.
These are a couple of string sets that are well suited to DADF#AD tuning. John Pearse and D'Addario. These strings can also be tuned up a tone to EBEG#BE on my standard scale guitar without a problem. This same set of strings works well on the long scale guitar for CGCEGC tuning. G Dobro tuning (GBDGBD) is too tight for these gauges.
The guitars are optimized to a string tension of around 70 to 80kgs. (150lbs) They will handle more tension than that, but dynamics will decrease as the tension starts to lock up the sound board. Although my guitars are stronger than most, you can still destroy them with excessive string tension by using the wrong strings for the tuning. Please use this chart as a guide.
The large wood inlays on the fretboard are much more visible than the standard inlaid dots used on Weissenborns etc, but if you were to include all the frets that are marked on a normal guitar (3, 5, 7, 9, etc) the markings become useless because they look the same. After a lot of experimenting, I have found that just using 5, 7, 12 and their octaves is by far the easiest way to find your position. I can do added markers for those who really want them, but I can promise you that after a couple of weeks of using this system, you would understand why it has become my standard. You really don't need a marker to show you 3 frets above or below the octave and you can always use stickers while getting used to it.