[sdiy] Anyone have schematics for a Kimball Organ rhythm machine?

[Adam Inglis]

On 27/04/2012, at 7:45 AM, aankrom wrote:

> Thanks to some helpful info from one of you, I've learned that my  
> unit is very similar to a Roland TR-77. The size of the units are  
> even similar, but the circuits are, as expected, not  identical. The  
> TR-77 has more features - some that I'd like to add. There's an  
> octal socket on the back of mine that looks like it could be  
> discrete outputs for each sound or maybe triggers. I'm curious as to  
> what could have been connected there.
>
> I wish my rhythm unit had each sound circuit marked on the PCB like  
> on the TR-77. I can surmise which is which based on the size of the  
> inductor bobbins, but that's about it. Some probing is in order...
>
> It will be cool when I have it all boxed with the 25W amp and the  
> reverb unit.
>
> Anyone who's hacked a TR-77 or a unit like it, I'd welcome input or  
> pointers to sources on the web. I like the tip on pushing buttons  
> for two patterns at once. I don't know yet if that will work on  
> mine, but I'm curious to see what comes out. The diodes on the  
> pattern generator are these weird black plastic blobs...
>

These guys have hacked into a Bentley Rhythm Ace to give the voice  
circuits midi-controlled triggers. The BRA looks to be a re-badged TR77
http://www.circuitbenders.co.uk/newsarchive/BRA.html

There was also a bit of activity on this topic here
http://www.burnkit2600.com/tr-77/
but I don't recommend the sync mod shown there, didn't really work for  
me. You need a positive pulse at 4 ppqn as mentioned towards the  
bottom of my page
http://www.adambaby.com/studiotech_TR-77.html

HTH




regards
Adam Inglis
http://www.adambaby.com