[sdiy] SSM2164 Phaser - another way?

[Neil Johnson]

Donald Tillman wrote:
>
> On Feb 19, 2014, at 2:17 AM, Mattias Rickardsson <mr at analogue.org> wrote:
>
>> The signal input of the 2164 is essentially a virtual ground, so your
>> 30k+2164  becomes essentially a constantly grounded 30k.
>
> That's the thing...  At high gain settings almost all of the 2164's diff amp gain is being steered to the output and almost none is feed back to the input, so there is not enough loop gain to consider it a proper virtual ground.  The input impedance of the 2164 will rise at higher gain settings.
>
> (Whether or not this a good mechanism for a phase shifter is another matter...)

No, it will just distort like hell.  You've basically described
saturating the input stage.  The result will sound terrible, unless
you specifically want it to sound that way of course.

Neil
--
http://www.njohnson.co.uk