Talking teacher

[the_zombiest]

I just got this today and it's vexing me to the point of insanity.

I've been probing for about 3 hours and have found a few glitches and that's pretty much it.  I've not been able to find a pitch bend or loop or anything remotely remarkable.

I had a look for schematics via the gift of google and found the coleco circuit but not the matchbox/tiger one, which happens to be the one i have.  The main thing that I noticed on the coleco was the lack of a crystal/xtal.  the matchbox version does have one, and i'm fairly sure that it's the reason I can't find a pitch bend.

Will replacing the crystal with any other component be of any use, or will it just break this infernal machine?

[Circuitbenders]

no pitch control on the matchbox version, you could try changing the crystal but you'd only get one differnt pitch.

The first time i had a go at a matchbox one it drove me mad as i couldn't find anything exciting but when i went back to it a month later i found loads of cool glitch loops, a distortion and a tight audio loop. Theres also a couple of random glitch points in there.

The coolest thing about the talking teacher is that you can just hold down the repeat button and it'll just glitch round and round in the same glitch pattern.

[the_zombiest]

I'm gonna try setting up a rotary crystal selector and see if that works.  I've *ahem* 'won' a coleco version on ebay so i'll just mod that all the way and have the matchbox version as a blue glitch box of dispair.  i might try linking the two and see what happens then.  Either way, i'll let you know the results.

[catweazle]

Linear Technologies sells a resistor controlled oscillator (kind of an VCO)  LTC6906 10kHz..10MHz.
The little problem is the packaging (SMD SOT23, very small)
check out:
http://www.linear.com/pc/productDetail.do?navId=H0,C1,C1010,C1096,P9790

or for friends of the good old analog electronics: (Capacitor controlled Oscillator, cheap and stable)
http://en.wikipedia.org/wiki/Clapp_oscillator

[the_zombiest]

Thanks for the info, i'm not sure i understand it entirely though as I'm pretty new to this.  The RSO looks like the more viable option but thinking about it is making my face melt.  however, I like a challenge so i reckon i'll give the RSO a whirl and if i find no joy, i'll go for the Clapp option.  It's all lessons to be learned.
Thanks again 

[the_zombiest]

ok, so I got a range of ceramic resonators and have successfully removed/destroyed the original on the pcb.  I can go as low as 2mhz up to 12mhz.  The original was 3.12Mhz.  The results mean that i can speed up the voice considerably, but i can only slow it a little.  All i need to do now is wire up a rotary switch and wire the 10 resonators to it and then find a loop on the goddamned thing.
I only have a break before make rotary as well and until i wire it up i dunno if it'll work or just turn off inbetween each selection... i'm guessing the latter unless I use my lightening fast ninja skills.
Keep you posted