Hey Luke!
It certainly wouldn't be too expensive to mail diodes to Switzerland,
but unfortunately my parts are all in storage now as I prepare to
move across the country.
The output amplifier is quite simple. It is a non-inverting opamp
with a gain of about two, followed by a buffer. Both of these
configurations are all over the web and used in other synth
circuits. I can't remember the values of the resistors in the amp,
but it's likely that the feedback and positive input resistor is
100K, and the negative input resistor to ground is 68k. That
arrangement would provide a gain of about 2.5. The output of the
buffer will need a 1K resistor in series with the output jack to
provide a current limit when plugging and unplugging. The power
supplies should be decoupled with small caps, say .01 mfd.
Chub
It certainly wouldn't be too expensive to mail diodes to Switzerland,
but unfortunately my parts are all in storage now as I prepare to
move across the country.
The output amplifier is quite simple. It is a non-inverting opamp
with a gain of about two, followed by a buffer. Both of these
configurations are all over the web and used in other synth
circuits. I can't remember the values of the resistors in the amp,
but it's likely that the feedback and positive input resistor is
100K, and the negative input resistor to ground is 68k. That
arrangement would provide a gain of about 2.5. The output of the
buffer will need a 1K resistor in series with the output jack to
provide a current limit when plugging and unplugging. The power
supplies should be decoupled with small caps, say .01 mfd.
Chub
--- In cgs_synth@yahoogroups.com, "poketo77" <poketo77@...> wrote:
>
> Hi Charles (and everybody else)
>
> Sory I didn't answer for so long time. But I've been buisy with
> school. So I hadn't any time for building electronic stuff.
>
> Thank you a lot for your offer with the Ge-diodes but I think it's
to
> expensive and complicated to send just a few diodes to Switzerland.
> I'll look in some old gear if I can find some of these diodes.
>
> But I'm interested in your RM output circuit with the TL072. Could
you
> e-mail it to me? Thaks a lot for your help!
>
> Cheers Luke
>
>
>
>
> --- In cgs_synth@yahoogroups.com, "Charles Osthelder" <osthelder@>
> wrote:
> >
> > Hi Luke!
> >
> > The parts for the ring mod are in the archives of this list. The
> > best transformers have a around 10K primary impedance and 2K
> > secondary. The DC resistance is about 600 ohms and 160ohms
> > respectively. Mouser has two transformers that work quite well.
The
> > larger is part # 42TM002 and the smaller (nice for pcb mounting)
is
> > part # 42XL002.
> >
> > The Ge diodes are a little harder to find, but I'd be happy to
match
> > a set for you free of charge. Just send me a mailing address and
> > I'll get them out to you.
> >
> > It seemed a good idea to add a makeup amp and buffer to the
output of
> > the RM circuit. Mine uses a TL072. The non-inverting amp has a
gain
> > of 2 (or so...) and the output of the buffer connects to the
output
> > through a 1K resistor for short protection.
> >
> > Chub
> >
> > --- In cgs_synth@yahoogroups.com, "poketo77" <poketo77@h...>
wrote:
> > >
> > > Hi anyone
> > > Recently I found Ken's page about his Modular synth. It's a
great
> > page!
> > > So now I've a question about the real Ringmodulator:
> > >
> > > Somehow I couldn't find some rigt transformers.
> > > What type of transformers are used in the Ringmodulator? It
would
> > be
> > > nice if you could tell me the ... as well.
> > > Could you give me a suggestion about the Ge-Diodes? I read
> > somwhere,
> > > that usually Shottky-Diodes (I don't know if they are caled so
in
> > > English) were used for ringmods.
> > >
> > > I hope you understand what I'm writing... English isn't my
mother-
> > > tongue...
> > >
> > > Thanks for your help!
> > >
> > > Cheers Luke
> > >
> >
>