[sdiy] MC1495 multiplier chip discontinued completely

[Scott Bernardi]

Here's a 1496 based ring modulator. Works real well.
http://home.attbi.com/~sbernardi/elec/og2/og2_ringmod.html

Scott Gravenhorst wrote:

> And I *still* have not built an audio ring modulator.
>
> I have a need for a very basic ring modulator, I have as choices: 1496
> and AD633.  I also have LM13600 and LM13700.  Of these, what is the
> best choice for this?  I don't plan to use it in a pitch shifter, just
> for timbre modification to get metallic sounds.  Will one of these
> work well enough for this purpose?
>
> Also, on the other end of the scale are really poor multipliers, like
> using a single FET which I guess is a one quadrant "multiplier".  Very
> nonlinear, but does this have viable uses?  After all, if one can do
> it to square waves with an XOR gate, an FET should be useful for
> *something*.
>
> Watching this decay into "unobtainium" is depressing...
>
> >From: "Czech Martin" <Martin.Czech at Micronas.com>
> >> I just learned from Arrow/Spoerle that the MC1495 multiplier chip
> >> is discontinued and they can not ship any more.
> >> On Semiconductor has accordingly made an update to their
> >> web site.
> >>
> >> So I guess the 1495 is *really* gone.
> >>
> >> The good thing about this chip was that it contained more
> >> or less matched transistors for the gain cell, so offset and offset
> >> drift was under control. I.e. carrier suppression was good.
> >> Compander circuits will not make a good job for this carrier
> >> suppression, because it is not a wide band noise problem,
> >> but very narrow, so masking is poor.
> >>
> >> And it had an input linearisation circuitry for the
> >> carrier input, in order to have quite linear behaviour.
> >> The (still available) 1496 is designed for square wave
> >> carrier and has of course no input linearisation.
> >> So you have to use low carrier amplitude (noise)
> >> or accept excessive sidebands (distortion, intermodluation).
> >> Also the 1495 allowed to taylor the gain cell bias current.
> >> For good S/N you need a lot of current.
> >> Most other integrated multipliers do not allow for bias
> >> current change and are designed for low power consumption,
> >> so S/N of 80 dB will be the upper limit, and most devices
> >> will not even give that (AD633 for example).
> >> For some applications this is still too much noise.
> >>
> >> I want low noise and linear behaviour (smooth sound).
> >> So next I try the RC4200 (?) and the 1496 with external DIY
> >> linearisation stage. If this doesn't work I'll go back to
> >> a complete discrete design, perhaps using a couple of
> >> japanese dual NPN, glue, expoxyd ... whatever it takes
> >> to cope with the offset problems...
> >>
> >>
> >> m.c.
> >>
> >>
> >>
> >
>
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