[sdiy] Newbie question: Diode ladders

[harrybissell]

Hi Scott


>  Diodes, BJTs, FETs, OTAs, MOSFETs, all seem
> to need attenutation (what about vactrols?) to avoid distortion.  Is the
> acceptable signal level applied at this point similar or the same for each
> of these techniques?
>

Vactrols DO have some change with signal level but it is the least by far of
all
those you mentioned.

Most FETs are in the 10s - 100s of mV range.
OTAs are usually less than 25mV at the device pins and that is PUSHING
it already. Probablt 10mV is a good figure.  If you use the diode
linearization
(like the CA3280) you can go much farther...

Transistors and diodes should probably be a small fraction of the total
drop...
again probably in the 10-20mV range

Vactrols, go ahead and whack them. They have to give you SOMETHING in return
for being so damn slow...

H^) harry