[sdiy] Karaoke echo chips and those pitch-shifting megaphones...

[aankrom]

Every now and then I post a topic about salvaging echo chips from 
karaoke machines/boomboxes because I have trouble finding datsheets for 
them. I still can't figure out exactly what the CD3197 is, but I know 
it's an echo chip that I have two of. I also have a CD3699 which I've 
discovered is the same as a PT2399, the one used in the Rebote delay 
project. Once I found a BL3207 in a karaoke machine. Is it me or are 
these noisier than the old Panasonic MN3207? I KNOW they're noisier than 
MN3007's because my homemade chorus pedal using an old MN3007 blows away 
most new pedals using an MN3207. Okay but I'm getting off track. There 
should be some kind of repository of datasheets and knowledge about 
commmonly used digital echo chips used in consumer electronics that are 
likely to be scavenged. Also those pitch-shifter chips. I have three of 
those "robot megaphones" that I took apart, but forget what a lot of 
wires are for. It would be cool to have a triple pitch shifter with a 
couple of cheap digital delay chips. Not to mention those old greeting 
cards that let you record and play back (some kind of "analog memeory").

Anthony