output jack

[Beeker]

Most toys I have bent I remove the speaker and use a 220k resistor to add a output jack. This usually makes for the right output volume for the output. I sometimes find that removing a speaker and putting a output jack gives me barely audible or no sound. What seems to be the problem and what can I do to make the toy audible? 

[Circuitbenders]

220K is very high. Have a look at this page http://www.epanorama.net/circuits/speaker_to_line.html

Sometimes you might find that the speaker appears to act like its part of the circuit, so you won't be able to actually remove it. In this case you might be able to get away with a dummy load, or just leave the speaker in place and wire an output off it.

[wax+wire]

on a similar note, how do you work out which wire is the speaker ground and which is the signal?  one i've done hums now because i have it backwards

[Circuitbenders]

A lot of the time it doesn't matter that much, but the speaker itself will probably be marked with a + or -. If it isn't you can often tell which is the ground by tracing back from where the wires join to the board. You might well find the ground connects to the negative power input and / or the output sockets ground somewhere along the line

[boneless]

I've just come up against this twice recently whilst bending crappy toys.

As mentioned usually a resistor equivalent to the speaker sorts it, but not for my burp-o-matic or hot-music so I had to wire their speakers internally into the new enclosures, and tap my line out off that.

This irked me, but I'm glad to hear sometimes that is the only option– thought it was just me being a dumb-ass....