[sdiy] A diy question was (DRAMA!!!)

[TooManySynths]

Ok, hi dieter, and everyone.

I hate to interrupt the doepfer bashing....but....I
have a question and I was hoping one of you might be
able to save me the embarrasment of going to radio
shack and buying reed relays.

I am modding my tama techstar 305, giving it some
bannana jacks, and making that "preset" switch do
something useful.  For each tone module it implements
some kind of accentesqe feature, ususally just
increased delay time.  The TS305 connects this switch
to some fets to do the switching in various places
with a single spdt switch. Each leg of the switch is
held at -15 through a 100k resistor and the center of
the switch is connected to +15 through a 1k resistor.
Each pole of the switch is also then connected to the
cathode of a diode, the anode of which, goes into a
fet.  Basically, the negative voltage turns each fet
off while the other is on.  The schematics are here:

http://home.camelot.de/fa/diy/tama305/schem.htm

What I want to do is use a gate signal to select the
memory position.  I'm looking for the simplest circuit
that will alternatly swap plus and minus to the fets
from a signal that goes from zero to plus five or so.

I can do this with a reed relay <sigh>, but I know
there must be a more elegant solution.  Hey, don't
give me grief, you can build a lot of junk without
really knowing what you're doing.

Thanks
Daryl






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