[sdiy] Re: moog high pass

[Magnus Danielson]

From: Paul Perry <pfperry at melbpc.org.au>
Subject: Re: [sdiy] Re: moog high pass
Date: Wed, 30 Jul 2003 20:19:20 +1000

> At 11:48 AM 30/07/03 +0200, Theo H wrote:
> >- The production model Voyager has HP, earlier prototype had not.
> > -Simple as in adding inverted LP filter output to input signal to get HP.
> >Takes about one opamp and 3 resistors.
> >
> 
> Is it really that simple?

No, you need some form of switch to de-select it and some form of summing of
lowpass, highpass contributions or however one wants to play the game.

> Granted, you would get a low pass filter this way.
> But, I doubt it would sound anything like, for example, the 
> patented Moog ladder high pass.

Indeed, it goes up a completely different tree.

> Because, the artifacts would be completely unalike.
> In an ideal, distortion free, filter, then I agree.

The question was not if you get "the same" but if you get a highpass filter
which is _usefull_. And I think you should come into the usefull department.

Friends of us sell Moog-ladders like this, and as I recall they get good
reviews. Hm... I'll think I will visit a friend and take a listen ;O)

Cheers,
Magnus