[sdiy] cloning the dr-110 - schematic question

[Karl Ekdahl]

First off i'd like to ask if replacing the 2SC2603F
with BC547, the 2SA1115F & 2SC945K with BC557 and
1SS133 with 1N4148 was a bad call? It seems to be
working so far...

But, my main question is the (13) symbol at the snare
part of the schematic (by r110), what is that supposed
to be connected to? Anyone? The schematic can be found
here: 
http://www.physicsenterprises.andrews.edu/diy_archive/schematics/drums/dr110/dr110.gif
(as usual, beware of wrap)

thanks

Karl