Author 
Intellijel Morgasmatron  video demos 
intellijel 
Intellijel Morgasmatron
In this first video we wanted to demonstrate some of the unique and interesting sonic possibilities with this filter. There is no talking, just a good variety of examples.
Details of each patch are in the youtube description.
Manual and more details here 

cackland 
Awesome stuff!!!
Currently awaiting my Morgasmatron! 

Muse FTW 
This sounds incredible. I didn't think I needed a new filter, but here we are. 

Dr. SketchnEtch 
Nice video, Dan! It always amazes me how many different sounds can be coaxed out of this beast. 

Trooper 
Great...thought i would need no more filter 

2disbetter 
Korgasmatron was great, but good bye, and hello Morgasmatron!
2d 

idm 
More GAS!
I'm in the market for a first filter on my modular. I'm sold 

matttech 
Very much looking forward to these bad boys 

ipnoteca 
really hope in an half version of this, maybe a polaris 2... 

christophin 
Can't wait to mess around with this beast! 

Sanys 
yay cant wait guys! 

FrogStar 
Has anyone seen a description of the filter cores/topography? Are they similar to the ms20 filters? 

Goin_noW 
wait!!!! 

Dr. SketchnEtch 
FrogStar wrote:  Has anyone seen a description of the filter cores/topography? Are they similar to the ms20 filters? 
The transfer function of the MS20 filters in series is:
This exact transfer function is obtained from the Morgasmatron when filter A is set to LP2, filter B is set to HP1, and the routing switch is flipped upward to series mode.
The Morgasmatron (like the Korgasmatrons before it) was designed based on the mathematics of the MS20 filters (the actual circuitry looks nothing like the original, but the math is the same), but it capable of infinitely more. 

alex5556 

cackland 
Quote: 
The transfer function of the MS20 filters in series is:

This seems rather straight forward 

beliefsystemrecords 

arthurdent 
Dr. SketchnEtch wrote: 
The transfer function of the MS20 filters in series is:

I remember having textbooks in college  usually for calculus or thermodynamics  that would have stuff like this with the statement "...and it's intuitively obvious to the casual observer...". 

Dr. SketchnEtch 
arthurdent wrote:  Dr. SketchnEtch wrote: 
The transfer function of the MS20 filters in series is:

I remember having textbooks in college  usually for calculus or thermodynamics  that would have stuff like this with the statement "...and it's intuitively obvious to the casual observer...". 
Actually, this equation is pretty obvious to anyone who has dealt with filter analysis and design before. It's actually the product of two distinct transfer functions, both with similar denominators, but different numerators. The denominators show a secondorder filter. The interesting stuff is in the numerator, which is a bit strange, and denotes a combination of 2pole bandpass and highpass responses from filter A (and a lowpass response from filter B, which gives the numerator "1" which simply acts as a multiplication factor for the A numerator). This hybrid A response acts like a 1pole highpass filter without resonance. This is why the MS20 filter gives such strange behavior with increasing resonance, and is probably the source of its unique character.
It's all in the maths, man! 

jambirn 
Dr. Sketch or anyone else, if you’d be so kind as to provide a walkthrough for artists interested in this math I’d appreciate it. Would really appreciate your insights. The math fascinates me but I don’t understand it.
Thank you!
Jim 

beliefsystemrecords 
jambirn wrote:  Dr. Sketch or anyone else, if you’d be so kind as to provide a walkthrough for artists interested in this math I’d appreciate it. Would really appreciate your insights. The math fascinates me but I don’t understand it.
Thank you!
Jim 
this. video series on youtube: filter math for extrem dummies 

Dr. SketchnEtch 
The attached PDF document called "Transfer Functions" is something I typed up in 2010, and was my attempt to really cement my own understanding of filter circuits. At the end of it is my first circuit concept for the original Korgasmatron. I hope you find it useful.
Note that, for the purposes of the current balances in the document, you need Ohm's law:
V = IR, or I = V/R
or, in terms of impedance
I = V/Z
and the similar law for a capacitor (in the Laplace or Fourier domain):
Z = 1/sC, or I = sCV
where s is the Laplace or Fourier variable. If you don't understand Laplace or Fourier transforms, you're not alone! Suffice it to say that these transforms play a mathematical trick where elements of calculus become elements of algebra. Hence, the actual capacitor law is:
I = C dV/dt
where dV/dt is the derivative of voltage with time. It is the rate of change of voltage on the capacitor of capacitance C when a current I is passed through the capacitor. Laplace transformation converts the differential thus:
dV/dt = sV
Hence, I = CsV = sCV
The Laplace variable s = jw, where j is the imaginary number (square root of 1) and w (actually the greek letter omega) is the angular frequency. I know, this doesn't make it much clearer.
Just remember: plotting the transfer functions in the document is what gives the amplitude vs frequency plots with which we are all so familiar for the various filter modes.
In the second document, I have summarized the various transfer functions and amplitude plots for the Morgasmatron. This filter core was designed completely from the mathematics. The letters A, B, C and D refer to the input signal gains routed to various points in the filter circuit (A into the first filter stage, B into the second filter stage, C into the resonance feedback stage, and D into an output inverter). By writing the transfer function generally assuming all four entry points, and then choosing the correct gains for those points, the six different Morgasmatron transfer functions were obtained. Note how modes 2, 4 and 6 are simply sums of modes 1 and 3, 3 and 5, and 5 and 1. This simplified things enormously! I'm not aware of any other multimode filter designed in this way. (The Polaris, for example, takes a different approach entirely.) Note that the original MS20 modes are the 2P LP and the 1P HP.
Have fun! 

neonmercury1 
wow!! thats increadible! thanks DR!
Now i have some good bedtime reading. 

beliefsystemrecords 

cackland 
Great overview and breakdown of the module from Intellijel.

