Roland JV/XP MIDI Tuning Standard Sysex for the Just Intonation Harmonic Scale There are two general areas in the synth's RAM for changing scale tuning values: (1) in the "native" (Model ID "6A") System area at address offsets from 00 00 10 00 Part 1 scale tune 00 00 20 00 Part 2 scale tune thru 00 00 1F 00 Part 16 scale tune 00 00 20 00 Patch Mode scale tune where the data value address offsets range from 00 00 thru 00 0B. This will ONLY affect the current TEMP Performance. It is NOT saved with a Performance, Patch, or Rhythm Kit. (2) and the GS (Model ID "42") memory area at address offsets from 40 10 00 Scale Tune Part10 40 11 00 Scale Tune Part1 thru 40 1F 00 Scale Tune Part16 where the data value address offsets range from 40 thru 4B. In BOTH cases the data vales from 0-127 represent a range from -64 thru +63, where 64 equals the Center range of 0. For either address values and their data to take affect the System parameter "scale tune switch" must be set to ON [1] at address 00 00 00 07. The sysex messages to turn the switch ON or OFF are: FO 41 10 6A 12 00 00 00 07 01 78 F7 Scale Tune ON FO 41 10 6A 12 00 00 00 07 00 79 F7 Scale Tune OFF The Just Intonation Chromatic scale consists of the following interval ratios: Scale Tones: C C# D D# E F F# G G# A A# B Ratio: 1 16 9 6 5 4 7 3 8 5 7 15 - -- - - - - - - - - - -- 1 15 8 5 4 3 5 2 5 3 4 8 The program "Pitch Palette" (www.justonic.com) provides realtime udpates of Root/Scale/Chord sysex tuning data from which the following scale tuning values were produced. To reset the JV/XP to "standard" equal-tempered tuning, either send the above Scale Tune OFF sysex message OR send, for example, the following sysex message for Patch Mode: F0 41 10 6A 12 00 00 20 00 40 40 40 40 40 40 40 40 40 40 40 40 20 F7 To determine the hex values for the respective offset values, ADD 64 to the offset value. For example, if the offset is -12, add 64 to produce 52 and convert to the hexadecimal value of 34. The "Pitch Palette" provided range offsets for Just Intonation for the Root of C are which are shown with their decimal and hex converted values: Pitch C C# D D# E F F# G G# A A# B Offset 16 27 20 31 2 14 -2 18 29 0 -16 4 Decimal 80 91 84 95 66 78 62 82 93 64 48 68 Hex 50 5B 54 5F 42 4E 3E 52 5D 40 30 44 Note that A=0 to keep the 440Hz tuning as a "reference" pitch. For simplicity's sake, only the Patch Mode scale tuning sysex message will be shown for the Root of C. The data would not change for the Performance Mode Parts, just the addresses, and checksums. Root Just Intonation Scale Tunning Sysex Message for PATCH MODE ==== ==================================================================== C F0 41 10 6A 12 00 00 20 00 50 5B 54 5F 42 4E 3E 52 5D 40 30 44 2F F7 "Pitch Palette" uses related tunings for each Root's subdominant and dominant scale degrees (4 and 5 respectively) to better provide consonance to chords. However these "retunings" differ from above in that they are relative to each other and NOT to the A=440Hz "default". I'll leave such "excercises" to the most adventurous .