[sdiy] Littleman VCO error (555 chip inverted)

[adam at hoodmusic.net]

Hi
    The littleman VCO is almost an exact copy of the PAiA Fatman VCO, only a
couple very small changes, but the same core structure. The drawing of it for
the littleman VCO looks to be correct, I can see nothing wrong with it.

http://www.paia.com/fatmwork.pdf

    get that pdf, it has a very good description of the VCO there

adam


Jimmy Gogas wrote:

> I'm looking at the Littleman VCO circuit, and I think that the 555 chip is
> inverted (mirrored --> 1 should be 8, 2 should be 7, etc.). Can anyone
> confirm that? I was also wondering if anyone can spot any other errors on
> the VCO (or anything you would improve on). Finally, does anyone have a clue
> about how this thing works? I know what the 555 chip does, but what exactly
> do the two pnp transistors do? How about the op-amps? And why are the
> resistors next to the PITCH connected like that? (Any other comments
> appreciated).
>
> The shematics of the Littleman VCO can be seen at :
> www.itn.liu.se/~nikro/littleman/littleman.pdf
>
> Thanks in advance.
>
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