That's my understanding as well: Just to clarify terms: An
ideal "balanced" modulator (4 quadrant multiplier), where a negative
modulator inverts the carrier, results in sum and difference signals
with no carrier or modulator present in the output. Classic
amplitude modulation (2 quadrant multiplication), where the carrier
is not inverted, does not eliminate the carrier signal from the
output.
You're absolutely right that the term "ring modulator" is
commonly used to refer to any balanced modulator (4 quadrant
multiplier), not just one constructed using the diode ring.
The point of the post was just to clarify the the terms and
their orgins, not to confuse things with fancy sounding words. Since
the important thing is sound, not terminology, its not really all
that important.
However, Ingo's CGS recording seems to show that a "real" ring
modulator sounds quite different from the balanced modulators we've
all gotten accustomed to. I wonder if our good friend Dieter
Doepfer would be interested in making a "real" diode ring modulator
that also has some active electronics to eliminate the pesky signal
loss in the CGS passive circuit. Would there be any interest in
this

K


--- In Doepfer_a100@yahoogroups.com , "ilanode" <techmeier@w...>
wrote:

>
> AFAK the difference btn amplitude modulation and ring modulation

is

> that only in the latter the carrier freq is no longer present at

the

> output... Wether this is done by an IC or diodes is soundwise of
> interest but doesn't affect the label. Regards, Ingo
>
> --- In Doepfer_a100@yahoogroups.com , "okiikahuna"

<okiikahuna@y...>

> wrote:
> >
> > I think that the only "real" ring modulator among the bunch is

the

> > CGS unit. I will explain my own limited understanding of this,

if

> > anybody cares. (If somebody with more technical knowledge sees a
> > mistake, please correct me)
> >
> > The term "ring modulator" refers to a a certain way of
> > acheiving "four quadrant multiplication." It is called "ring"
> > modulation because the circuit uses four diodes arranged in what
> > looks like a ring in the circuit diagram. The only unit that
> > actually uses this circuit is the CGS.
> >
> > The term "Four quadrant multiplication" just means a kind of
> > amplitude modulation where a negative control voltage will

invert

> the
> > carrier signal. Here's an explanation of the this term: A

regular

> > VCA is a "two quadrant multiplier." The control
> voltage "multiplies"
> > the signal at the input. So, a zero signal gives no output
> because 0
> > times anything equals zero. The input signal can be positive or
> > negative, but the multiplier signal can only be positive, a
> negative
> > control voltage has no effect. So there are two "quadrants."
> > positive control and positive input or positive control and
> negative
> > input.
> >
> > So, "Four quadrant multiplier" just means that the control

voltage

> > can be negative. When a negative multiplies a positive, it

gives

> a
> > negative, so a negative signal inverts the input. This is what
> > all "ring modulators" do, regardless of whether they actually

use

> the
> > diode ring circuit or not. (However, different circuits clearly
> add
> > various kinds of additional artifacts, judging by the different
> > sounds Ingo got.)
> >
> > So, changing "ring" modulation to amplitude modulation in a four
> > quadrant multiplier (Like the A-133) just means changing the
> control
> > signal from bipolar to all positive. This can be done by adding

a

> > positive offset voltage to a bipolar control voltage.
> >
> > Of course, this is really just tech-trivia since it doesn't help
> > anybody to figure out what sounds you will get by doing this.

Only

> > way to figure that out is by doing what we all do: plug wires

and

> > turn knobs.
> >
> > K
> >
> > --- In Doepfer_a100@yahoogroups.com , "selfoscillate"
> > <synaptic_music@y...> wrote:
> > >
> > >
> > > hello ingo (the not self-oscillating :-)),
> > >
> > > afaik the a133 is not really a ring modulator, but like a vca,
> > > it can be used to achieve similar effects.
> > > i'll record a sample using the a133, but i cannot
> > > do this before weekend i guess. i still have some troubles
> > > with my recording card. one time it works, the next time it
> > > doesn't. computers can be a pain in the ....
> > >
> > > best wishes
> > >
> > > ingo
> > >
> > >
> > >
> > > --- In Doepfer_a100@yahoogroups.com , "ilanode"

<techmeier@w...>

> > wrote:
> > > >
> > > > Is the A133 really capable of both amplitude and ring
> modulation
> > > > There's no info referring to this on the Doepfer HP. Anyhow,
> > Ingo,
> > > > if you don't mind I'd like to hear some examples of amp/ring
> > > > modulation with the A133. Regards, Ingo
> > > >
> > > >
> > > > --- In Doepfer_a100@yahoogroups.com , "selfoscillate"
> > > > <synaptic_music@y...> wrote:
> > > > >
> > > > >
> > > > > hello,
> > > > >
> > > > > i tried the a133 too, but i haven't recorded it, because i
> > > > > wanted to compare only dedicated ring modulators.
> > > > > you are right, the a133 can also be used to generate
> > > > > ring modulator effects. damn, i should have recorded
> > > > > that module too.
> > > > >
> > > > > best wishes
> > > > >
> > > > > ingo
> > > > >
> > > > >
> > > > >
> > > > > --- In Doepfer_a100@yahoogroups.com , "okiikahuna"
> > > > <okiikahuna@y...>
> > > > > wrote:
> > > > > >
> > > > > > --- In Doepfer_a100@yahoogroups.com , "ilanode"
> > <techmeier@w...>
> > > > > wrote:
> > > > > >
> > > > > > I think you guys might have missed Doepfer's "other"

ring

> > > > modulator
> > > > > > in your otherwise exhaustive comparison. The A-133
> Polarizer
> > > is
> > > > > just
> > > > > > a 4 quadrant multiplier and seems to make a fine

balanced

> > > > > modulator.
> > > > > > Just adjust the carrier for the least amount of leakage
> with
> > no
> > > > cv
> > > > > > applied, then put the modulator signal into the CV jack.
> You
> > > can
> > > > > vary
> > > > > > it continuously between balanced modulation and ampitude
> > > > modulation
> > > > > > by turning the knob or applying an offset. To me, the
> sound
> > > > seems
> > > > > > most similar to the unmodded A-114, which raises lots of
> > > > > interesting
> > > > > > questions about the effect of DC v. AC coupling, since

the

> A-
> > > 133
> > > > is
> > > > > > clearly DC.
> > > > > >
> > > > > > Although it has been a few years since I have played

with

> > one,
> > > I
> > > > > have
> > > > > > very fond memories of the sound of the Buchla 100 series
> ring
> > > > > > modulator. Does anybody know what was in this circuit
> Was
> > > > there
> > > > > > anything special about it
> > > > > >
> > > > > > K
> > > > > >
> > > > > > > --- In Doepfer_a100@yahoogroups.com , denis goekdag <q-
> > > > art@g...>
> > > > > > > wrote:
> > > > > > > >
> > > > > > > > it's really easy to assemble one or two cgs ringmods
> from
> > > > the
> > > > > > > assembled
> > > > > > > > boards you can buy, just take an 8 hp blindplate,
> drill 6
> > > > 8.2mm
> > > > > > > holes
> > > > > > > > for the s6 sockets, hot-glue the two cgs boards to

the

> > > plate
> > > > > (the
> > > > > > > > transformer's "casing" allow this quite smoothly),
> wire
> > the
> > > > > > > sockets,
> > > > > > > > done.
> > > > > > > Yes, probably the most simple DIY project around. The
> most
> > > > > > > complicated part is to get in touch with Ken of CGS at
> > least
> > > > he
> > > > > has
> > > > > > > never replied to my mails. > :( Ingo
> > > > > > >
> > > > > > > > Am 15.11.2005 um 18:09 schrieb Zoran Bosnjak:
> > > > > > > >
> > > > > > > >
> > > > > > > > > Ingo,
> > > > > > > > >
> > > > > > > > > thank you so much for the example! I like the CGS
> ring
> > > > module
> > > > > > > the
> > > > > > > > > most. What
> > > > > > > > > a pity it is not offered assembled. I still have

to

> get
> > > > the
> > > > > > > soldering
> > > > > > > > > lesson
> > > > > > > > > #1 before trying to figure it out myself... (Does
> > anybody
> > > > > offer
> > > > > > > basic
> > > > > > > > > electronics course in Montreal )
> > > > > > > > >
> > > > > > > > > Regards,
> > > > > > > > >
> > > > > > > > > Zoran
> > > > > > > > >
> > > > > > > > >
> > > > > > > > >> From: "selfoscillate" <synaptic_music@y...>
> > > > > > > > >> Reply-To: Doepfer_a100@yahoogroups.com
> > > > > > > > >> To: Doepfer_a100@yahoogroups.com
> > > > > > > > >> Subject: 1 Re: comparing ring
> modulators
> > > > > > > > >> Date: Tue, 15 Nov 2005 10:38:39 -0000
> > > > > > > > >>
> > > > > > > > >> --- In Doepfer_a100@yahoogroups.com , "ilanode"
> > > > > > <techmeier@w...>
> > > > > > > wrote:
> > > > > > > > >>>
> > > > > > > > >>> --- In
> Doepfer_a100@yahoogroups.com , "selfoscillate"
> > > > > > > > >>> <synaptic_music@y...> wrote:
> > > > > > > > >>>>
> > > > > > > > >>>>
> > > > > > > > >>>> hello antonio,
> > > > > > > > >>>>
> > > > > > > > >>>> the missing lows in #5 are probably because the
> > > > > > > > >>>> cgs real ring is a passive device, the output
> > > > > > > > >>>> loudness is weak on this module.
> > > > > > > > >>>
> > > > > > > > >>> Just want to add that the RRM is known to load

the

> > VCOs
> > > > and
> > > > > > > thus
> > > > > > > > >>> affecting their performance. The results would

be

> > > > different
> > > > > > if
> > > > > > > the
> > > > > > > > >>> inputs of the RRM were buffered. One could add

an

> Op
> > > Amp
> > > > to
> > > > > > > each
> > > > > > > > >>> input or (if I'm not mistaken) 2 Analogue
> Solutions'
> > > > MX224
> > > > > > > > >>> Mixer/Buffer Modules. Obviously the latter is

not

> > very
> > > > > > > economical.
> > > > > > > > >>> Regards, Ingo
> > > > > > > > >>
> > > > > > > > >>
> > > > > > > > >> i usually use those mx224 buffers in front of the
> cgs
> > > > real
> > > > > > ring,
> > > > > > > > >> but i didn't in my example, because i wanted to
> show
> > the
> > > > > > > > >> significant differences of the loudness.
> > > > > > > > >> anyway, if you use those buffers, the output

level

> of
> > > > > > > > >> the cgs real ring is still much lower than on the
> other
> > > > > > > > >> ring modulators.
> > > > > > > > >>
> > > > > > > > >> best wishes
> > > > > > > > >>
> > > > > > > > >> ingo
> > > > > > > > >>
> > > > > > > > >>
> > > > > > > > >>
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> > > > > > > > >
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > Yahoo! Groups Links
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