Professor Aaron D. Lanterman shared this video lecture, Moog Ladders Filter Analyzed, part of his course ECE4450: Analog Circuits for Music Synthesis class at Georgia Tech.
The presentation was originally planned to be the in-person lecture of the Spring 2020 session of the class, but Lanterman moved it online, as a result of the Coronavirus pandemic.
The discussion is not intended for a lay audience, but will be of interest to synthesists with a background in engineering or electronics.
16 thoughts on “Analog Circuits For Music Synthesis: The Moog Ladder Filter Analyzed”
Thanks to the virus, I can with confidence say that I’ll never have anything to do with analog modular. It’s interesting to see & hear what rich people do, though, sometimes, not these days, not for me, though. But some people like that sort of thing!
I am sorry to hear that but don’t forget the circuit is modelled and similar are available in various soft synths
This is the most cloned design in the history of analogue synthesis. This is far from unobtainium these days, realistically.
And yet, there is no pedal of it I know of since they discontinued the MF-101. And afaik no DIY PCB to build it into a pedal, you’d have to mod a eurorack PCB, which I am too novice to do.
Interesting what you’re saying. If that is true then there’s a gap in the market waiting to be filled there!
Or it may be this is the most basic way of constructing a chain of 4 transistor based differentials with feedback. You kinda may wonder how it was even possible to patent something like that considering how straightforward this design is.
Hindsight is 20/20.
I guess it’s good to be rich and analog.
Thanks for the link!
The Moog ladder filter is probably one of the most elegant and beautiful electronic circuits ever devised.
You haven’t seen a lot of circuitry then.
^^ Wow, this exchange is *so* internet! 😀
Yeah, the iconic one upsman-knucklehead move. A classic! 🙂
More on this topic: Analysis of the Moog Transistor Ladder and Derivative Filters, by Tim Stinchcombe. https://www.timstinchcombe.co.uk/synth/Moog_ladder_tf.pdf
Lots of unhappy people here. We aren’t talking a 907 or 914, here. These aren’t expensive components.
I’m wondering why a term “Butterworth” never appears when disputing about Moog’s ladder filter.