Roland GP-8 Quick start guide

o Reconnecting IC35 of MT board
Change connection of IC35 pin 6(Gl) from
a +5V line to IC23 pin 54.
CHANGE
INFORMATION
~JJ!~pg
o IC35l::~tt~~l!
IC35 6. 1:. /' (/) ~ ~ 9c. ~. +5V7 -{ /' iJ> t:J IC23(/)
54. l:" /' "" ~ ~
REASON
For more positive synchronization of IC22
(gate array)and IC35 operational timings.
This will prevent the following problems:
* Inproper Chorus effect
* Incorrect LED reading
* Disabled effect even it is set to on
togather with other effect(s).
MODIFICATION
SN761000 - 783499 MT board 7314466001
(S~e Fig.A and B.) Jumper connect 'IC35
pin 6 to IC23 pin 54 with unnecessary foil
pattern cut.
SN783500 - UP
(See Fig.B.)Relayout foil pattern MT board
to provide the above reconnection.the part
number of MT board is changed to 7314466002
(pcb 2292043502).
JIm
IC22 (-'I - ~ 7 i- -i ) C: IC35(/)!1J fF 7' -{ ~ ~ .y
~Jii~{,:l, riC~*(/)~~~IfJj.1tT~o
* :J-7A~l!~'it
* 7~:7·LED~~~'it
* ilf{(/).J:7:I.:7?~;t/'l-rt, {-(/)?
is (/) - "? iJt f1J iJ> ":t ~'o
~1J'iE~
I, fl ~ 761000 - 783499
;£ f!i MT;f- - /-. 7314466001 (pcb 2292043501)
( Fig. A, B ~ ~ ) /~ 7' - /' 7J "/ ~ .& rJ -;; 1" /' /~
tilt ira JJI1
2, fl~ 783500 - UP
(Fig.B~M) /-e7'-/'~~, .:tL'::f*~,MT;f-
F,;t 7 3 1 44 6 6 0 0 2 (p c b 2 2 9 2 04 35 0 2 ) C: ":t ~ 0
MT BOARD SN761000 - 783499
Fig. A
VIEW FROM PARTS SIDE
~£m
CUT PATTERN
/~ '7 - /' fJ ':J f-
SN761000 - UP
MT BOARD
Fig.B
JUMPER
;;'1' /d~ r---t~_:o
-I---~~------t--1~
17