External Expression Pedals - Boss

GT-X Setup Manual

value dial, the mechanical mini-switch buttons and the
display and 2) the actual second PCB.
If you are not able to identify the right mini-switch
connectors, you need to take first the 1) & 2) block (lots of
screws!!) apart and then 1) and 2) apart from each other by
first popping the value dial out from the backside and then
unscrewing the nut of the value dial.
Identify the right connectors. It helps to hold the board
against the light and to use a multi-meter to check which
connectors short circuit when you press the mini-switch.
Each mini-switch has 2 connectors, a led parallel to the
mini-switch above it and a diode (methinks) vertically on
the side (alternating left/right side).
Solder 4 connector wire (say, 30-40 cm long) to the
"manual" and tuner/bypass" mini-switch connectors. Make
a note of the colour coding of the wires you soldered (I had
red & green -pair and white & blue -pair).
Assemble the parts back.
Before you screw the back plane back, test your wires:
Power the unit, and shortly short circuit the pairs - if
everything went fine you'll be able to turn the manual mode
/ the tuner on and off by short circuiting the respective
pairs. These switches work in unlatching mode, so the wires
in a pair need to touch each other only for a very short
period (kind of giving a "pulse" to the unit) i.e. they do not
need to stay connected!
If everything is ok, you need to attach a jack to the wire to
make it practical to use; I drilled a hole between the big GT-
3 text and the guitar input jack for this purpose. I was
planning to use a 4-connector mini-din jack for it, but I took
by chances and tested whether all the 4 wires are really
needed and they are not - it works with 3 wires only!
(Disclaimer: seems to work, I have not thoroughly tested
this thing, so it is possible that I will someday notice that all
4 are really needed...).
I did not notice this while the unit was open and un-
powered (remember, there are the diodes and who-knows-
what...) but I was curious enough to test it and take my
chances of the consequences. So, I noticed that it does not
matter whether (my colour coding follows...) the green wire
touches the red OR the white to get the desired result. And
the same applies to the blue wire!
Therefore, as 3 wires are enough, you can use standard
6,3mm stereo jack or even a 3,5mm stereo jack so that you
do not need to drill such a big hole. I used the bigger one
(did not need to alter my SUB CTL pedal cable...).
If you use conventional metal-bodied 6,3mm TRS stereo
jack (or respectively the mini 3,5mm headphone jack or any
© Copyright 2000-2002 Barry S. Pearce et al.
Section 4
other jack where the body is connected to one of the
contactors to be used...) you have to isolate the sleeve (/the
jack) from the GT-3 body (common earth!), otherwise the
mod will not work!!
Connect the (again, my colour coding follows..) 'common'
wire (red in my case) to the sleeve, green to sleeve and blue
to tip. Test your external pedals. The order of green and
blue does not really matter other than to the left-to-right-
order of manual/tuner (if your pedal control order is
'hardwired'). If you can order your pedals anyway you
prefer or if you use an insert cable in the pedal end you
swap the insert cable in the pedal end the green/blue order
doesn't matter at all. I use home made pedals, so I just
solder them into the order I like (manual left, tuner right,
just like on the mini-switches). I left the white totally
unconnected, as I did not seem to need it. I decided not to
connect it to red as they do not seem to be directly
connected to each other.
Screw your back cover back and you are ready!
In the end, it looks very clean and the cost is negligible; I
had the wire and the jack already available, other parts are
not needed. It took me about three hours all the way, but I
am no fast hand shredder, trust me! Besides, I was lurking
the GT-3 chat at the same time (until my computer hang...
:-).
Thanks to Simonen for that.
I have dwelled on this matter further and have considered
that you can in fact wire up a lot more pedals; in fact, you
can sort of recreate manual mode with individual pedals –
the problem is it takes 2 presses of each pedal to turn an
effect on or off and then you need to have wired an EXIT
button as well so you can go back to the main screen to
change patches. It may be that just doing the Manual &
Tuner buttons can provide the most benefit. Still, perhaps
the idea will unlock the genius of someone somewhere –
and if you have any great ideas tell the rest of us on the list!!

External Expression Pedals

Sometimes these cause people problems. If only it were a
case of plug-in-and-go. But it isn't quite. There are a couple
of things to trip you up here. So let's examine a patch set-up
to check your external expression pedal works. I did this
with a Roland EV-5, but there are a number of pedals
(including from other manufacturers) that will work
satisfactorily. Whilst we are doing this I will point out the
important bits as we go.
Select an empty patch
Turn off the EXP PEDAL control assign (Failing
to do so can cause conflicts if both are set to
control FV:Level).
Connections
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