I have seen one or more definition files for this device on this forum, but they did not fully comply with the character format of Pyramid. That is why I post my file here. I tried to use as many understandable abbreviations as possible.
NAME:JX-03
OUT:A
CHANNEL:1
1:MODLTION
3:LFO RATE
5:PORTMNTO
9:LFO DLY
11:EXPRSION
12:LFO WAVE
13:O1 RANGE
14:O1 WAVE
15:O1 LFO
16:O1 ENV
17:O2 RANGE
18:O2 WAVE
19:O2 TUNE
20:O2 FINE
21:O2 XMOD
22:O2 LFO
23:O2 ENV
24:O LFOMOD
25:O ENVMOD
26:O ENVPOL
27:SRCE MIX
28:F LFOMOD
29:F PITCHF
30:F HPF
31:F ENVMOD
35:F ENVPOL
46:VCA ENV
47:VCA LEVL
53:SUSTAIN
64:HOLD
65:PORTA ON
71:RESONANC
72:RELEASE
73:ATTACK
74:CUTOFF
75:DECAY
82:DELAY T
83:DELAY FB
86:ASSIGN
87:BEND RNG
91:DELAY LV
93:CHORUS