Battery power

[grenert]

If a rail-to-rail quad opamp that could operate at 6V were used instead of the LM324, could the entire circuit be powered by 6V?  This may permit running this on 4xAA batteries.  What is the current draw of the voice circuits?

[Circuitbenders]

If you can find a quad opamp that will give you approximately 5v output pulses from a 6v supply, then i guess it'd probably work, but you would probably have to adjust a few resistor values and the trigger pulse width going into the voice circuits is going to change as the battery voltage drops so the sounds will be different.
The output pulses from the trigger conditioning circuit are actually around 5.4v, as thats what they are in the DR55.

If you want to run the thing from batteries, i suspect it'd be better to just leave out the trigger conditioning, and trigger the sounds using definite 10ms pulses at the TRIG_IN2 trigger points instead.