[sdiy] Silonex optocouplers

[Electronium]

Hi Grant,
I looked at the silonex products also, and it seemed as though the NSL-37V51
might be pretty close to a VTL5C3... although the ON resistance was higher.
(I wonder if this really isn't a typo, since the numbers are identical other
than ohms or k-ohms)

Did I miss something?

Thanks!
Mike Brown
mike at electronium.com

----- Original Message -----
From: "Grant Richter" <grichter at asapnet.net>
To: "Tim Parkhurst" <tparkhurst at siliconbandwidth.com>;
<synth-diy at dropmix.xs4all.nl>
Sent: Thursday, October 24, 2002 11:53 AM
Subject: Re: [sdiy] Silonex optocouplers


> Hi Tim!
>
> The subject of audio optocouplers is pretty subjective.
>
> I reviewed the Audiohm products. In general, they are slower than their
> Vactrol counter parts.
>
> BUT, if you build a Buchla Lowpass gate out of a Hamamatsu ultra high
speed
> optocoupler, it will sound like a Korg MS-20 not a Buchla Lowpass Gate. An
> even slow optocoupler will have a different sound to it.
>
> So the optocouplers themselves and their attack and decay times figure
into
> the finished sound.
>
> This is actually good, as you can get two different results from the same
> circuit using different optocouplers.
>
> As always, the best results are obtained by experimenting until you find
> something pleasing to your ear.
>
> Actual response curves vary by at least 30% so expect to use a lot of
> trimmers for zero and span.
>
> > From: Tim Parkhurst <tparkhurst at siliconbandwidth.com>
> > Date: Wed, 23 Oct 2002 15:21:44 -0700
> > To: synth-diy at dropmix.xs4all.nl
> > Subject: [sdiy] Silonex optocouplers
> >
> > Hello All,
> >
> > Has anyone tried the optocouplers available from Silonex? They have a
very
> > wide range of parts along with some ap notes and schematics for audio
> > applications. Maybe a good Vactrol substitute? Maybe even a replacement
for
> > the now defunct Burr-Brown VCA610 in powered speakers (Peter G)?
> >
> > http://www.silonex.com/audiohm/index.html
> >
> > The web site states
> > "Silonex Audiohm optocouplers are ideally suited for high performance
audio
> > circuits. Most "design-ins" have demonstrated proven performance
benefits
> > over silicon based audio control devices such as VCAs and FETs. Audiohm
> > optocouplers act in a circuit as a passive component, like a resistor,
but
> > are very dynamic. Effectively the component is a current controlled
variable
> > resistor."
> >
> > They list Allied as a distributor. A check showed several of the items
in
> > stock, and prices ranging from about 2 to 4 bucks a pop. The NSL-32SR3
looks
> > particularly interesting. It ranges from 60 Ohms to 25 Meg (!) and has a
> > 'decay time' spec (time to 100K after removal of current through the
LED) of
> > 10msec. Might make for a fairly wide range VCADSR.
> >
> > Tim Servo
> >
> >
> >
> >
> >
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