There's loads of different VTech toys released under similar names, is this one you have?
Circuit Bent VTech Alphabet Desk PhonicsIf so, then there are two circuit board types that I've come across! One is roughly square with regular components, and gives some good noises and a few glitch noise streams. The other is a small rectangle with SMD components. Couldn't get anything decent out of the SMD one. I can't remember clearly, but I think it was a crystal driving this one. I injected/replaced the signal with a couple of various oscillators, not sure if the 4011 worked, but if not the LTC did. Still, nothing worth drilling a hole in the front for!
There is a way to tell which circuit board you have before you buy one - check the number on the back.
For the big board, look for the number 17 (specifically on mine, 53-17000-002). The ones with 36 or 37 contain the smaller, pointless board. I think it's just those two digits that change and the rest of the serial number is the same - I just wrote down to avoid the 36 and 37!