http://midi-overdrive-switcher.becosfx.com
20
For example, if Multi Function hex switch is set to 2, it means that in pedal Bypass the External
Swithcing Relays are Off, in effect only Relay 2 is On and in extended mode, both relays are On (see
Table 1 above). Concomitantly, the pedal sends MIDI messages on MIDI Channel 2:
PC# 1
when pedal is in Bypass,
PC# 2
when pedal is in Effect,
PC# 3
when pedal is in Extended mode.
With TS8-MS as "MIDI Controller", you can cycle through three MIDI presets on your other MIDI
devices and switch amplifier channels at the same time. Of course, to do so, you also need to connect
the External Switching Relays to the amp's external switching connector using either a stereo or an
"Y" stereo to 2-mono cable, as previously explained.
TS8-MS Customizations
Swapping IC's
There is a whole debate around the "sound & feel" of IC's used in overdrive circuits! The differences
are more
felt in the "playing hand" than heard by the ear
. Sometime they have an influence in
conjunction with guitar pickups and amplifier's channel/setting used, for a cumulative, more obvious
effect.
You can swap IC's with ease, without taking apart anything but the back cover of the pedal, so we
encourage you to experiment. Here are some IC's to try:
RC4558D/P - warm saturation, classic tubescreamer sound, used by most manufacturers
TLC2272 - low noise, gentle musical clipping, good for hi-gain crunch
OP275 - very "clean", low noise with nice recovery from clipping
OPA2604 - low distortion, quiet, gentle clipping, a bit darker sounding
Other: TL072, NE5532, LM833, OPA2134PA, LT1214
Changing Clipping Semiconductors
Why change diodes in overdrive circuits?
Diodes all have different forward voltages from around
0.2V for Germanium and 0.6V for Silicon diodes and going up to and over 3V in some LED's. Guitar
pickup signal level can reach something above 0.2V depending on magnet's strength, so, when pedal
gain is set low with the Gain Control, the signal is almost untouched, but as the gain increases or
when you hit strings harder, the amplified signal is limited by these diodes
sooner
or
later
,
depending on type of diode used and their configuration.
This is what causes the
clipping/distortion.
You can succesfully use any diodes with forward voltages in between 0.2V to
2.0V for overdrive applications.
In TS8-MS overdrive, Symmetric and Assymetric settings are hardwired with Silicon diodes which
clip arround 0.55V each, while Custom is configured with sockets where we placed our selection of
