my understanding is that they wouldn't share ground even running off
the same wall wart; there's no earth pin on those. but i don't know
why this would matter. if you really wanted to connect the grounds you
could just solder a wire from one machine to the other. i wouldn't
guess that you would mess anything up, but don't take my word for it,
circuitbending has a relatively high failure rate. but if you are just
shorting address pins (staying away from the power and ground pins) i
would risk it.

--- In tr-707@yahoogroups.com , "philo_707" <philo_707@...> wrote:
>
>
> OK, so I got a working clock circuit, interesting it wouldn't go when
> I powered it off a 5v cell phone charger, but worked great off a ram
> chip...needed to share the ground.
>
> So, anyway, here's an idea: shorting the sound chips on a 707 to
> those on a 727 -- not when they're on the same machine per the "70727"
> mod, but with two fully intact machines running side by side. I'm
> guessing they would need to share ground, so I was thinking of running
> both of them in parallel off a single 500mA universal that I have.
> I'm afraid that it would fry both of them, though I really don't see
> why, can any of you electronics gurus think why this would be
dangerous
>
> After all, you can short the main chips to the ride/crash chips
> without issue, would this be any different Also, just thought of
> this: what if I just tried it out by running them off the same power
> strip--they would share ground that way too, right
>