Fw: [sdiy] Passive Ring Modulator

[John L Marshall]

One of the inputs on some of the transformer coupled ring modulators is DC
coupled to the ring. These will work as a VCA. The problem is that the ring
works in four quadrants. Therefore, the DC control voltage must go to
exactly zero for minimum output, a challenge.

Try the one transistor phase splitter. The issues are equal voltage levels
and equal impedance.


Take care,
John
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Pacific Northwest DIY Synthesizer meeting, July 20, 2002
See: www.sound-photo.com
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----- Original Message -----
From: "Scott Gravenhorst" <music.maker at gte.net>
To: "John L Marshall" <john.l.marshall at gte.net>;
<synth-diy at dropmix.xs4all.nl>
Sent: Thursday, July 18, 2002 6:26 PM
Subject: Re: Fw: [sdiy] Passive Ring Modulator


> "John L Marshall" <john.l.marshall at gte.net> wrote:
> >Choose resistors to match the desired impedance. How much current can the
> >two sources deliver? And at what voltage? 1k ohm each?
>
> Sounds good.
>
> >I would expected the resistor versions to have substantial losses,
burning
> >most of the power in the resistors, delivering little to the output. But
> >then, all of the transformers issues go away.
>
> I'd have to agree there.  If I can get it to work with a 4069, I still
> have at least 2 gates to use as an output amp.  It certainly looks
> like something worth throwing on the solderless breadboard.
>
> >I like the idea of two resistors and a center trim pot to balance the
> >circuit. Pick your favorite frequency to zero the trim pot.
>
> I didn't exactly say it that way, but that is what I meant.
>
> Hmm.  I also wonder if a standard 1 transistor phase splitter might
> work for the input +/- drive, cap coupled.  (the xfmr one won't work
> with DC anyway... a VCA it isn't)
>
> >Take care,
> >John
>
>---------------------------------------------------------------------------
> >Pacific Northwest DIY Synthesizer meeting, July 20, 2002
> >See: www.sound-photo.com
>
>---------------------------------------------------------------------------
> >
> >----- Original Message -----
> >From: "Scott Gravenhorst" <music.maker at gte.net>
> >To: <synth-diy at dropmix.xs4all.nl>; <uzs159 at uni-bonn.de>
> >Sent: Thursday, July 18, 2002 5:25 PM
> >Subject: Re: Fw: [sdiy] Passive Ring Modulator
> >
> >
> >> I like the transformerless ones.  Questions:
> >> 1) any clues as to the resistor values? (range?)
> >> 2) what performance difference is there between xfmr and non-xfmr?
> >> 3) the resistors Rx, should this be 2 resistors and a trimpot?
> >>
> >> I realize that the resistor method would need opamps under most
> >> circumstances to get inverted and noninverted copies of the input
> >> signals which defeats the "no power" aspect, but it does eliminate
> >> the 1496 or whatever.  I would like to experiment with a 4069 operated
> >> as linear amps for that, I like the way they distort.  one 4069 would
> >> be enough with 2 inverters left over.  The 4069 would have to be run
> >> off of a dual supply (+/- 7.5 volts, technically, but I've done this
> >> with +/- 8 and have heard of it done with +/- 9)
> >>
> >>
> >> René -- might this one work for your simple squaring circuit?
> >>
> >>
> >>
> >> =?iso-8859-1?Q?Ren=E9?= Schmitz <uzs159 at uni-bonn.de> wrote:
> >> >--=====================_1027029223==_
> >> >Content-Type: text/plain; charset="iso-8859-1"
> >> >Content-Transfer-Encoding: quoted-printable
> >> >
> >> >
> >> >Some nice ringmodulator circuits. Especially picture 40 b, leads to=20
> >> >a transformerless implementation.
> >> >
> >> >Cheers,
> >> > Ren=E9
> >> >
> >> >>Reply-To: <lsh at wo.cz>
> >> >>From: "Jaroslav Lukesh" <lukesh at k-net.cz>
> >> >>To: "Ren=E9 Schmitz" <uzs159 at uni-bonn.de>
> >> >>Subject: Fw: [sdiy] Passive Ring Modulator
> >> >>Date: Thu, 18 Jul 2002 20:57:15 +0200
> >> >>X-FeelingPriority: Normal
> >> >>X-Mailer: Muj vlastni Mail klient 1.00    =20
> >> >>
> >> >>There I was post, but my mails does not arrive to synth-diy. Try
these.
> >> >>
> >> >>It is very little known ringmod solutions (and very easy).
> >> >>
> >> >>Regards JL.
> >> >>
> >>
> >> =========================================================
> >> - What good are laws that only lawyers understand?
> >> - Government: The other religion.
> >> - The media's credibility should always be questioned.
> >> - Lambs who lie down with lions are lunch.
> >>
> >> -- Scott Gravenhorst | LegoManiac / Lego Trains / RIS 1.5
> >> -- Linux Rex         | RedWebMail by RedStarWare
> >> -- FatMan: home1.GTE.NET/res0658s/FatMan/
> >> -- NonFatMan: home1.GTE.NET/res0658s/electronics/
> >>
> >>
> >>
> >
>
> =========================================================
> - What good are laws that only lawyers understand?
> - Government: The other religion.
> - The media's credibility should always be questioned.
> - Lambs who lie down with lions are lunch.
>
> -- Scott Gravenhorst | LegoManiac / Lego Trains / RIS 1.5
> -- Linux Rex         | RedWebMail by RedStarWare
> -- FatMan: home1.GTE.NET/res0658s/FatMan/
> -- NonFatMan: home1.GTE.NET/res0658s/electronics/
>
>