MOTM

Perhaps any guitar players out there might know the answer.  Is there a standard configuration from footswitches for amps?  What I'm thinking about is the footswitch that lets you select the amp's "channel" you play through.  

I'm interested in this because I started daydreaming about a footswitch controller router MOTM panel.  Something with 3 routes: bypass, route1, and route2.  The footswitch has three buttons, and you select which channel you like just by tapping on it (i.e., no cycling through).  Perhaps an internal jumper that selects how the non-selected channels are muted:  before send (which allows any trailing sounds from a reverb or chorus to gradually die off) or after return (which would cut off any trailing sounds but would also prevent any sound generated in-route from coming through).

--PBr

Disclaimer:  non-engineer who thinks he sees a nice solution:

It certainly appears to me that the heart of this circuit you want could be
a single SSM-2404 chip just like the one used in the MOTM-700.  If I am
looking at this right, this chip has 4 independent SPST voltage controlled
switches.  Paul has the control in the MOTM 700 wired so that if one is on,
another is off.  However, the chip can operate these separately so that all
/ any can be on, or all any be off (by applying 5 volts to a particular
control pin for that switch)

There are many ways to wire the control depending on exactly what you want.
If it were me, I would make the thing voltage controlled and use some cheap
op amps in a comparator / window comparator arrangement so that with 0-1
volts no output were selected, 1-2 volts output is selected from input 1,
2-3 volts output is selected from input 2, 3-4 volts output is selected from
input 3, and 4-5 volts output is selected from input 4.

Then you would have a stand a long 4 in 1 out, or 1 in, 4 out switcher that
can be controlled from any voltage.  Then, I would build the foot switch to
produce voltages in the appropriate range.

But, this may not be the most simple control approach.  I am certain there
are many ways to do the control side.  But, a range of voltage control gives
you something that has many uses.  Regardless of how I did the control side,
I would probably follow Paul's example and use the SSM2404 or something
similar for the audio path.

Sounds like a fun project.
Larry Hendry

----- Original Message -----
From: Brousseau, Paul E (Paul) <noise@...>
To: <motm@yahoogroups.com>
Sent: Wednesday, July 17, 2002 1:50 PM
Subject: [motm] Footswitch question...


Perhaps any guitar players out there might know the answer.  Is there a
standard configuration from footswitches for amps?  What I'm thinking about
is the footswitch that lets you select the amp's "channel" you play through.

I'm interested in this because I started daydreaming about a footswitch
controller router MOTM panel.  Something with 3 routes: bypass, route1, and
route2.  The footswitch has three buttons, and you select which channel you
like just by tapping on it (i.e., no cycling through).  Perhaps an internal
jumper that selects how the non-selected channels are muted:  before send
(which allows any trailing sounds from a reverb or chorus to gradually die
off) or after return (which would cut off any trailing sounds but would also
prevent any sound generated in-route from coming through).

--PBr

>It certainly appears to me that the heart of this circuit you want could be
>a single SSM-2404 chip just like the one used in the MOTM-700.

That's a good idea.  Another approach to consider is that most amplifiers
with channel switching and many effects with a bypass feature use relays.
While they aren't "clickless" or as fast, it would be a simpler design.