just wondering if anyone knows, a lot of the newer toys i find i crack open and find there isn't much to bend, and they almost always have this hard black plastic-like chunk in a circle somewhere on the board and the traces definitely go under this chunk... is this there purely to prevent modification or repair? or is whatever is under that liittle blob actually useless and the board actually has no bends? or am I nuts? any info would be great... ~AJB
Underneath theres a tiny chip that contains virtually all the circuitry for whatever machine it is and the black blob is just a resin coating to protect the chip. Most of the time they are difficult or impossible to bend as theres just not enough of the functionality assessable. You'll be lucky if theres more than the power supply rails, the speaker output and the control inputs outside the blob. You'll often see a clock speed resistor right next to the blob that can be replaced with a pot for pitch control but thats usually about it.
Even though you can only mess with the pitch resistor, you might still get worthwhile results.
A body contact will usually work & produce a cool effect because your body acts as an antenna for hum and you'll get a 50 Hz frequency modulating thing going. 60 Hz if you're in the USA!
Sometimes a body contact to either side of the resistor works, when you bridge it your finger will be a resistor in parallel. If the original resistor is quite a high value then your finger in parallel will very likely have an effect.
Author
Logged
