actually, you don't need to have a ground associated with the 555
output, since the chip shares a ground with the 707. you could use
shielded wire and ground the shield to a ground point on the 707,
might eliminate potential crosstalk.

i get a little crosstalk on mine, but i think it has to do with the
proximity of the actual 555 circuits. the rim clock input is affected
slightly by the clap clock. wait a second, i guess it can't be
crosstalk or i would get weird pitch modulations. i think the 555 just
affects the frequency of the other one. so i guess i don't get any
crosstalk. i used ribbon cable from the 555 outputs.

--- In tr-707@yahoogroups.com , "philo_707" <philo_707@...> wrote:
>
>
> I understand that you all have used pins on other chips to power and
> ground the 555 oscillators, but what are you using to ground the 555
> outputs That is, if the 555 output is hooked right into a clock pin,
> where is the ground associated with that ouput placed
>
>
> BTW, IC10 appears to be there for cartridge use only, no luck with
> replacing that chip. I traced the schematics and it looks like I may
> fried IC32, "voice select," so that's the next attempt. I will repair
> this 707, damnit, it will happen.
>
>
>
>
> --- In tr-707@yahoogroups.com , "philo_707" <philo_707@> wrote:
> >
> >
> > Thanks for the response. I think you're right on both points. BTW,
> > this isn't a voice chip, it's actually a data buffer that Roland
> > sourced from Toshiba. I ordered the chip yesterday, if I get good
> > results I'll definitely post. It's IC10, which from the schematics
> > looks to interface the memory cartridges with the CPU, but
> > apparently the trigger data (or something with that effect) from the
> > internal memory is routed through there too. Shorting pins 2 and 3
> > will trigger sounds, but don't do it because I'm about 90% sure
> > that's what fried the chip. I could be wrong, maybe some random
> > chip downstream is fried, but I have a good feeling about this.
> > Anyway, if you ever do a 707, stay the hell away from IC10, and I'd
> > stay away from 8 and 9, too. For that matter, I'm sticking to the
> > voice chips and the env generators from now on.
> >
> >
> >
> >
> > --- In tr-707@yahoogroups.com , "kingconga42" <kingconga8@> wrote:
> > >
> > > --- In tr-707@yahoogroups.com , "philo_707" <philo_707@> wrote:
> > > > can I
> > > > put in a chip from a different manufacturer so long as they have
> > the
> > > > same part number
> > >
> > > i would guess.. yes. but- if it's a voice chip, won't you need to
> > burn the right
> > > data onto it
> > >
> > >
> > > > Also, for bit scrambling, is it safe to connect pins of the ROM
> > chip
> > > > to different ROM chips,
> > >
> > > i've done the bit scrambling with a tr-505 and an alesis hr-16.
> > I'd say as long
> > > as you stay away from the 5V+ pin, you'll be ok. Heck, i'd even go
> > so far as to
> > > say you can connect different chips in DIFFERENT MACHINES, but i
> > haven't
> > > tested that yet.
> > >
> > > -justin
> > > = burnkit2600.com =
> > >
> >
>