CA 3080 Tri to Sine converter question

[Scott Bernardi]

Electonotes did a study on distortion of both FET and 3080 tri to sine
converters (I'm not at home so I don't have the reference with me). If I
remember correctly, the FET converter gave less than 1% THD and the 3080
about 1.5% - not too bad, actually. The 3080 had better THD when there was
still a slight point left in the tops and bottoms of the waveforms.
I'll look up the references when I get home.


>My concern when implementing the Tri-Sin converter is "Just how pure is
the sine output?"  On the scope it *looks* good but I lack the
instrumentation to really measure the purity.  Can anybody quantify the
purity of the sine output for an optimized Tri-Sin converter using a 3080?
>
>John Speth
>Object Engineering, Inc.
>johns at oei.com
>
>-----Original Message-----
>From:	JWBarlow [SMTP:JWBarlow at aol.com]
>Sent:	Wednesday, May 20, 1998 6:07 AM
>To:	synth-diy at mailhost.bpa.nl
>Subject:	CA 3080 Tri to Sine converter question
>
>Hi all
>
>I was thinking about those CA 3080 tri to sine converters in Barry Klein's
>book recently, and it occurred to me that rather than build one into each
>oscillator, it might be nicer to have a few undedicated converters sprinkled
>throughout one's system as independent waveshaping modules. Has anyone tried
>this? Will it put out a good sine wave from a variety of different triangle
>sources (such as 3340, ARP, ASM-1 LFO), or does each converter need to be
>"tuned" for each oscillator? It may also provide interesting timbres for non-
>triangle waves. Maybe you could have (switchable) front panel controls for
the
>shape and symmetry.
>
>Just a thought.
>John B
>
>
>
>
--------------------------------------
Scott Bernardi
voice: 415-538-0439 (note new number)
fax:   415-904-8375
scott.bernardi at fritz.com