[sdiy] SSM2164 Phaser - another way?

[Donald Tillman]

Going back to the original post...


On Feb 18, 2014, at 7:29 AM, Tom Wiltshire <tom at electricdruid.net> wrote:

> I know that phasers with the SSM2164 aren't anything new, but I wondered if anyone had tried this:
> 	http://www.electricdruid.net/images/SSM2164Phaser.png

A good version of this circuit, using the 2164 as a variable resistor in a standard phase shift circuit, would work something like this:

Tap off the capacitor with a source follower, invert that with an inverting stage, apply that to the 2164, output of the 2164 back to the capacitor.

This turns the 2164 into a voltage controlled resistor.


> If it works, I think it saves one op-amp per stage over the "usual" APF version, like Hoshuyama's:
> 	http://userdisk.webry.biglobe.ne.jp/000/024/65/1/Vcph0505.GIF

Wait a second, this was all about saving an opamp?!?!

  -- Don
--
Don Tillman
Palo Alto, California
don at till.com
http://www.till.com
650 888-9632