This is ringing a bell. I don't remember the name, unfortunately.
The unit looked sort of like a blue-gray speak and spell, but one without a keyboard. Instead of the keyboard, imagine a shallow tray with recessed gridlines that held in place little clear plastic blocks containing electronic pieces with a schematic-type symbol on the top. and electrical contacts on the sides.
There was battery power on one end of the tray and a speaker on the other.
It was a lot easier to use than the Radio Shack nnn-in-one sets, although I don't think it had as many "experiments".