[sdiy] Aries modular schematics detail

[jh.]

> > I don't think the use of transistors is essential to the design, such as
the
> > difference between the Moog transistor ladder and the EMS diode ladder.
>
> I agree with you here.  I analyzed the transistor ladder phase shift
> network using a simple transistor model (voltage controlled current
> source), and found that it is equivalent to a diode ladder.

I think I did the same analysis some years ago, but came to different
results.
But that's all I remember - I must look it up again.


> Actually, I suspect that the transistor/diode ladder networks (not
> Moog complementary transistor ladder for high pass filter) can not be
> exact phase shifter (all pass filter), because each stage is not
> isolated.

If memory serves, *that* was the difference between using diodes and emitter
followers. Single stage would be the same, but transistors prevent loading
effects. But as I said, memory is very cloudy here, I must look again.

Transistor ladder is still no perfect all pass filter, though. That's why
this
phaser sounds much better with resonance than without I guess.

JH.