further notes:

-i had to remove a piece of metal from the volume board that was in
the way of the stacked up ic19 and ic22. it seems to work fine
without it, but if i start picking up radio stations or something
i'll put it back in, undo the mod, and redo it without the sockets.
you'll see what i'm talking about.

-the volume, panning, and filtering of the sounds seems slightly
different than when in the original machine. i raised the volume of
the kick and some other things. the differing filter and volume
resistors are on the volume board. doing it the other way and
putting the 727 sounds in the 707, the differences might not be
bothersome. i plan to experiment more, and maybe remove the filters
altogether.



--- In tr-707@yahoogroups.com , "gregory zifcak" <foleymachine@y...>
wrote:

> i managed to add switches to switch between the 707 and 727 roms

the

> other night. it was really simple. it's only really that cool if

you

> need a small setup like me, but here it is-
>
> what you need:
> -wire
> -spdt switch (4)
> -10k resistor (8)
> -razor blade for cutting traces
> -28 pin ic socket (4)
>
> the instructions are the same for all the voice roms (i think

ic34,

> ic35, ic19 and ic22, check the schematics), so i'll just write
> instructions for one.
>
> oh, label the roms before you remove them from the machine you are
> cannibalizing, otherwise you might get mixed up and all hell will
> break loose.
>
> 1. solder 28 pin socket on top of the voice rom, connecting all

the

> pins except pin 22 (pin 1 and 28 are marked on one side of the
> board).
>
> 2. snip pin 22 off the socket.
>
> 3. cut the circuit trace leading to pin 22 rom.
>
> 4. place new voice rom in the socket, being careful to pair new

ic34

> with old ic34, etc.
>
> 5. solder 10k resistors between pin 22 and ground (pin 14 i think)
> on both voice roms. i soldered to the top of pin 22 of the new

rom,

> since the bottom of the pin is in the socket.
>
> 6. solder a wire from the original point that pin 22 was connected
> to (i think it's ic29 pin 8 for ic34 and ic35, and ic29 pin 11 for
> ic19 and ic22, double check the schematic) to the middle lug of an
> spdt switch.
>
> 7. solder one wire from pin 22 of each of the stacked roms to each
> side of the spdt switch. i used the resistor legs as a handy point
> to solder to.
>
> the end
>
> other notes:
> -you don't need to connect separate wires to the middle lugs for
> ic34 and ic35, you can just connect the middle lug of the second
> switch to the middle lug of the first. same goes for ic19 and ic22.
>
> -you can use less switches for less flexibility, i.e. dpdt for

both

> ic34 and ic35 if you want. i like it this way because i can have
> bongos, hi-hats, quijada and ride all at the same time, etc.
>
> feel free to ask me questions if you are unsure about anything.