[sdiy] CMOS CD4046/4070 ring mod??

[media at mail1.nai.net]

At 11:59 AM +0000 12/28/01, Tony Allgood wrote:
>
>>>The Radio Shack MG-1 used the 4046 VCO as a high frequency oscillator
>>>for a top-octave doo dah for its polyphonic output.
>
>>Really??  I always wondered what that was.  So they are square outputs
>>using a 4046 with a divider in the loop??
>
>The 4046 is being used as a high frequency VCO only. There no PLL stuff
>here... er, I think, I don't think its doing the Polymoog thang here.
>Although David Luce was involved with both.

Well, you lost me on this one!!  I'd have to see a schematic, as I've spent
very little time with an MG-1 to remember what "polyphonic" sounded like.

>>That makes sense, although I do not think it is any different than any
>other XOR gate, such as the quad XOR CD4070 already being discussed.
>
>Yes, thats right. My point entirely. Its simply being used to perform
>the ex-or function on the two square waves from the VCOs. Works quite
>well really.

I'm guessing since the 4046 was being used as free-running VCO, Phase
Comparator I was simply an unused XOR.

>Shame about the colour scheme of the front panel though.

Personally, I don't like any of the "lesser" Moogs, but that's just my opinion.