Re2: [sdiy] overclocking BBDs

[JH.]

Thanks to all who replied!

> Like CMOS, it is really simple:
>
> P ~ C*f*V²
>
>C you can't do much about, f you want to raise, V is the supply voltage.
So,
>if you can't ensure propper cooling, lower the supply voltage.

Magnus: The big question is: which C?

The MN3005, for instance, is spec'ed to have 2.8nF input capacitance
(I guess that's 2.8nF for _each_ clock input?), but then again the clock
inputs are driven by *external* transistors (the clock driver), so some,
if not most, of the heat might be dissipated outside the BBD chip.

I plan to use a discrete clock driver, with small power transistors,
like the old Dynacord effects did.

Would be interesting to know what the _internally_ switched capacitors
add up to.

I'll have a MN3005 and a short BBD (most likely a TDA1022), clocked
from the same driver. But maybe that's not such a good idea then.


>I don't think you run into any other mechanism of destruction. The
transistors
>will go into current limitation and you will rather see drop of amplitude
>response.

Ok, I'll watch the chip with my finger then. I can afford a few dead 1022's,
but no dead 3005.

JH.