[sdiy] ALFA clone chips?

[John Staapel]

About TZ
Curtis suggest it to do TZ with a 3345, jurgen haible did the same with a
3340.  Probably SSI VCO  TZ works the same.
Curtis write in this article
The one major problem we have observed is internal beatings of the output
as heard and seen on an
osciIloscope . Theoretically, if the carrier frequency is an even multiple
of the modulating frequency, then
the new sidebands created will be harmonic. However, we observed that as
we  increased the modulation
depth, these beatings would begin to occur, especially after we passed
through zero, Lndicating that the
sidebands being produced were becoming non-harmonic .
As the depth was increased further, the sound would go through alternate
states of beating very rapidly and
not beating at all. The trimmer with A1, whose purpose is to trim the
absolute value circuit, did not seem to help. Any
suggestions from our readers would be very much appreciated.

Op zo 28 mrt. 2021 om 18:39 schreef Schwarz Raphael <raphschwarz at gmail.com>:

> Hi
>
> There is Jürgen Haible implementation of TZFM on the 3340 but it seems it
> does not work very well.
> It's somewhere in the archive you have to dig it up a bit.
>
> Le dim. 28 mars 2021 à 15:05, Mattias Rickardsson <mr at analogue.org> a
> écrit :
>
>> What's a TZ 3340?
>>>>
>>>
>>> Through-Zero.
>>>
>>
>> ... which is a feature of the new SSI2130 VCO, if anyone would need it in
>> a dedicated VCO IC design. :-)
>>
>> It feels like the CEM3340 "reverse sync" is designed to help the
>> implementation of TZFM, but I can't recall seeing it described. Perhaps it
>> was one of those functions not ending up perfect enough?
>>
>> /mr
>>
>>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at synth-diy.org
>> http://synth-diy.org/mailman/listinfo/synth-diy
>> Selling or trading? Use marketplace at synth-diy.org
>>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at synth-diy.org
> http://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20210328/b150b602/attachment.htm>