Hi Gregory

Actually, I just built the oscillators in a small external box with 6
pots for tuning....from there i just modified the 808 so you could run
external sounds through its hats/cymbal/cb circuitry....which would
cut the internal hex oscillators (they are at the beginnning of the
chain).

They shouldn't have any affect on one another if you give the ic a
well regulated power supply, did you add a largish electronic capitor
connected to it's power pin & ground (de-coupling)

Mine were stable enough that i could tune 'em all together or to make
chords, but tuning got hard at the high range (very sensitive)....if i
was to do it again i'd probably use multi-turn pots for better freq.
control.

From what i've read, you have 9 555 clocks If that was the case,
there would be a need for 2 hex inverter IC's, maybe one could form a
cowbell out of the remaining two oscillators :) Only joking, cowbell sux..

Seeya

Ryan

--- In tr-707@yahoogroups.com , "gregory zifcak" <foleymachine@...> wrote:
>
> i actually tried this before i did the 555s. i had the hex schmitt
> chips because i was following your 808 reports on AH and hoping to
> build a version of the hh, cy and cb circuit (still gonna do it!). for
> some reason, the individual pitch controls of the schmitt oscillators
> interfered with each other quite a lot. if i remember correctly they
> were soft-syncing each other so raising one pitch would raise others
> with it. didn't you do individual pitch controls for the hex schmitt
> in an 808 did you see this behavior it would definitely be an
> attractive solution if someone could get it to work. much more elegant
> than a s-load of 555s.
>
> --- In tr-707@yahoogroups.com , "plutoniq9" <Plutonique9@> wrote:
> >
> > I wonder if you could substitute a single Hex Schmitt-Trigger IC (i.e
> > CD4069) to produce the clocks instead of 555's, as you can form 6
> > oscillators from a single chip.....with minimal external parts (1
> > capacitor + 1 pot per clock), you could easily build it on one of
> > those mini RS pcb boards. The formula for freq is in the datasheets.
> >
> > Just a thought
> >
> > ryan
> >
> > --- In tr-707@yahoogroups.com , "gregory zifcak" <foleymachine@> wrote:
> > >
> > > well, i don't think it matters what kind of caps you use for
555s and
> > > decay envelopes. i've had them work fine with polarized
electrolytics
> > > and ceramics.
> > >
> > > as far as the clocks, mine dip down into the audio range at their
> > > lower end. you should be able to hear a faint whine if you touch
their
> > > outputs to the 707 outputs. if you can hear output, they should work
> > > as clocks. accordingly, you can use these clock circuits as audio
> > > oscillators if you use a bigger cap. there is a free dos program
> > > called 555.exe which calculates the frequency of the oscillator when
> > > you type in the values of the cap and resistor.
> > >
> > > --- In tr-707@yahoogroups.com , "philo_707" <philo_707@> wrote:
> > > >
> > > >
> > > > Hmm, I'm def. a little confused about this one. I know the
555s I'm
> > > > using are right, I followed the schematic posted here except for
> > > > changing the resistor and cap values to the ones mentioned that
> work,
> > > > but no go yet. Would any .1 uf cap work
> > > >
> > > > For that matter, on the decay mod, will any 1.0-10 uF cap
replacing
> > > > the stock ones work Do they need to be electrolytic or non, or
> does
> > > > it really matter
> > > >
> > > > About the LCD, I bought a dead parts unit that probably has a
> good LCD
> > > > on it, so even if I am successful in my attempts to revive the
fried
> > > > one, I may have one nonetheless.
> > > >
> > > >
> > > >
> > > >
> > > > --- In tr-707@yahoogroups.com , "Bart Provoost" <bart@> wrote:
> > > > >
> > > > > >
> > > > > > To the guy who needed an LCD, I'm still doing repairs, but it
> > looks
> > > > > > like I will likely have a extra working LCD anyway, we'll see.
> > > > >
> > > > >
> > > > > That's interesting ;)
> > > > >
> > > > > Bart
> > > > >
> > > >
> > >
> >
>