The D550 has three-and-a-half octaves of fully chromatic range; the lowest note is the G two octaves below middle C. It is configured in a 16/15 configuration, meaning there are 16 courses of strings on the treble bridge and 15 courses on the bass bridge. A super-bass bridge on the left provides the lower half octave as well as the chromatic notes that don't normally show up in the dulcimer tuning scheme.
The overall range is G2 to E6; the chromatic range is C3 to E6.
This configuration is for instruments with serial numbers after 13168. For earlier instruments, download a PDF file of the tuning chart.
Superscript numbers indicate octaves (C4 is Middle C).
Dots indicate marked courses.
All strings have loop ends.
Wire gauges are shown in inches.
PB = phosphor bronze wire.
PBW = phosphor bronze wound.
SSW = stainless steel wound.
Unspecified strings are plain steel wire.
Downloadable string/tuning chart:
for instruments after serial #13168
for instruments before serial #13169
Downloadable string order form