[sdiy] Lego synth anyone?

[harrybissell]

Note to all... you may (usually) only parallel gates within the same package.
They match well enough for that. Differences between packages may produce
toasty results.

Paralleling transistors can lower noise as the signal is in phase, while the
noise is random and 'should' cancel out. A few transistors produces a benefit...

more have the law of diminishing returns...

H^) harry

anthony wrote:

> > In his BBD based delay module, Thomas Henry parallels some inverters for
> > increased drive. What are you trying to achive.
>
> I dunno exactly but I have a bunch of 564 PLL's. I think I'll make a stacked
> VCO.
> I have 5 so I'll make one with just one and another with four and compare.
>
> I wish my frikkin 'scope worked. I think all of the pots are toast - they're
> noisy beyond even slightly useful.I can't bring myself to scrap what used to
> be a really nice 2 trace scope. Even if it does have a 10-turn pot with
> counter knob. I already have two of those... Still... I've considered just
> taking everything off the front and just adding whatever I need to see audio
> waveforms. Or I could just use Scopion with tinyHost.
> But I digress.
>
> > In the high end DBX/THAT VCA's they had as many as 8 VCA's in parallel.
> > They do this because the signal level goes up much faster than the noise,
> > so with every additional VCA the noise gets lower. I don't remember the
> > formula, their single VCA's are quiet enough for me.
> >
> > Mark
>
> Hmm that gives me an idea for the 3 LM1894 DNR noise reduction chips I have.
> It works by reducing bandwidth of audio instead of dynamic range like
> compandors.
> But there's a couple gain cells in there. And a peak detector. They might be
> more interesting in series as a SVVCF...
> Probably nothing fruitful but interesting experiment even though if I come
> up with something  really cool, few people would be able to duplicate it
> since I'm pretty sure the LM1894 was discontinued a long time ago (even
> though it's a cool system that works pretty well