AW: Re: Germanium Diode Filters?

[Haible_Juergen#Tel2743]

> I've run a guitar signal into a pair of back-to-back germaniums under
> various conditions and I was completely surprised at how awful it
> sounded.  Really.  Sort of sitar-like, a buzzy sproing.  Silicon
> diodes and LEDs sounded much more like a tube amp.

Yes, it's surprising. Even Marshall (who have a certain reputation ...)
chose LEDs for their tube-less preamp products.
Anyway, I am still wondering why it is like this and not the other way
round. Germaniums *do* have a "smoother" rounded threshold,
don't they? So a rounded threshold can't be the whole story ...

BTW, the weirdest thing I have seen so far was a combination
of si and ge diodes, to form a nonlinear voltage devider, like
this (Spice synthax):

D1   input      output   silicon_type_diode
D2   output   input      silicon_type_diode
D3   output   0             germanium_type_diode
D4   0             output   germanium_type_diode

May also have been the other way round (ge's in signal path,
si's to gnd). Anyway, a quite complex transfer curve.
Sound? Not bad, not outstanding either.

JH.