Cassette Loops and 424 Mods

[chipaudette]

Hi All,

I dug out my old Portastudio 424 (Original!) to start making some noise/drone/ambient textures. I'm starting with making some continuous loop cassettes. I'm having some success. I got a little demo video and how to at the link below, if you're interested...

http://synthhacker.blogspot.com/2014/02/cassette-tape-loop.html

Moving forward, I'd like to do some modifications to my 424 to enable some non-traditional uses of the device. For example, I'd like to add a switch to disable the erase head. I'd also like to setup some internal electronic loopback to enable some audio feedback without have to use external cables. All of these mods would be much easier if I had a schematic (or the service manual). Does anyone have the schematics for the original 424?

Thanks,

Chip

 

[chipaudette]

I've been exploring how to defeat the erase head in my Portastudio and found some success. I've got some how-to pictures (and audio demos!) here:

http://synthhacker.blogspot.com/2014/02/portastudio-defeating-erase-head.html

Chip

 

[DJ X]

Awesome, thanks for sharing.

 

[chipaudette]

Doing some live looping now...

http://synthhacker.blogspot.com/2014/02/portastudio-live-looping.html

Chip

 

[chipaudette]

I think that I've figured out how to have greater control over the tape speed...monophonic mellotron, here I come!

http://synthhacker.blogspot.com/2014/03/portastudio-voltage-control-of-speed.html

Chip