Mura Filter

From the Japanese term for the waste of uneveness this filter will create an uneven distortion of the resonance structure both from the transistor and from the diode in the feedback path.  Connections are described in the picture.  Values can be changed somewhat to match standard values.  RS is a rail splitter.  Saving the other side for an LFO to modulate the Fco.  Have not built this yet but it looks pretty cool in the simulator.

Falstad circuit simulator code:


$ 1 5.0E-6 0.9891409633455756 50 5.0 50
r 336 320 272 320 0 4700000.0
c 336 224 336 192 0 1.0E-9 0.00268564673175871
c 432 224 432 192 0 1.0E-9 -1.876367065692067
r 272 320 272 368 0 47000.0
c 272 320 224 320 0 1.0000000000000001E-7 -2.4144869775373956
174 336 192 432 176 0 100000.0 0.9059 Q 100k
a 336 336 432 336 0 15.0 -15.0 1000000.0
w 336 224 336 240 0
w 336 288 336 320 0
w 432 224 432 240 0
w 432 288 432 336 0
g 336 352 336 368 0
g 272 368 272 384 0
O 432 336 432 368 0
174 336 192 240 176 0 100000.0 0.9257000000000001 Fco 100k
g 240 192 240 208 0
w 288 176 336 192 0
R 224 320 192 320 0 2 100.0 5.0 0.0 0.0 0.5
r 336 288 384 288 0 2000000.0
r 384 288 432 288 0 2000000.0
g 384 240 384 224 0
c 384 288 384 240 0 1.0E-11 -0.939194425306891
w 384 176 336 192 0
w 432 240 432 288 0
w 336 240 336 288 0
w 336 160 336 192 0
w 448 288 432 288 0
174 336 160 432 160 0 1000000.0 0.005 Resistance
d 464 160 464 192 1 0.805904783
w 384 144 336 160 0
w 432 160 464 160 0
w 464 192 464 288 0
w 464 288 448 288 0
t 288 128 288 160 0 1 0.45948822583066745 0.4568213771495246 100.0
w 272 160 240 160 0
w 240 160 240 192 0
w 304 160 336 192 0
R 288 96 288 64 0 1 40.0 3.0 2.0 0.0 0.5
174 288 96 304 128 0 1000000.0 0.10400000000000001 Resistance
w 304 112 288 96 0
o 13 4 0 34 20.0 9.765625E-5 0 -1

Note the resonance wave form has a slight sawtooth edge as well as only oscillating on the positive cycle of the square wave.

Very Strange Filter 2

I decided to put this into a case.  I get these boxes at Office Max for about $1.50.  They drill out pretty easily with the Dremel dry wall attachment.  Have all the hardware attached at this point but still need to add the wires.

The top of the box.

This shows the circuit board in the box.  No wires attached yet but all of the components are in place.  This is basically a three part filter.  Probably a bit silly of me to make this without breadboarding it first since I don't really know what it will sound like.

Pendula

Created some sound in Csound based on this video I found on Youtube:


https://soundcloud.com/hmikelson/pendula 






<CsoundSynthesizer>
<CsOptions>
;-RWfo pendula.wav
</CsOptions>
<CsInstruments>
;---------------------------------------------------------
; Pendula
; Inspired by Youtube video of pendulums of various lengths like this one
; http://www.youtube.com/watch?v=eZm_-2O8ovI&list=UUeQEKFH31vvD-InkTGSvCrA 
; Hans Mikelson March 2013
;---------------------------------------------------------
sr = 44100 ; Sample rate
kr = 44100 ; Kontrol rate
ksmps = 1 ; Samples/Kontrol period This must be 1 to make sure to update time appropriately
nchnls = 2 ; Normal stereo
;---------------------------------------------------------
; Pendula
;---------------------------------------------------------
instr 50
idur = p3 ; Duration
iamp = p4  ; Amplitude
il0 = p5  ; Length of pendulum
ib = p6  ; Damping factor for pendulum (smaller damping will ring longer)
ig = p7  ; Gravity
kdclk linseg 0, .005, 1, idur-.01, 1, .005, 0
atime init 0  ; Need to start time at 0
atime = atime + .1  ; Time is incremented each sample
ialpha0 = ib/2/il0 ; Calculate alpha exponential decay factor
aamp0 = 1*exp(-ialpha0*atime) ; Calculate exponetial decay
aout0 = aamp0*cos(sqrt(ig/il0-ib/il0/il0)*atime) ; Calculate the oscillator times amplitude
apan = .5 + aout0/2
outs aout0*iamp*apan*kdclk, aout0*iamp*(1-apan)*kdclk ; Amplify and output
;outs aout0*iamp*sqrt(apan)*kdclk, aout0*iamp*sqrt(1-apan)*kdclk ; Amplify and output
;outs aout0*iamp*kdclk, -aout0*iamp*kdclk ; Amplify and output
endin
</CsInstruments>
<CsScore>
;-------------------------------------------------------------------------
f1 0 65536 10 1
; Pendula
; Sta Dur Amp PendL Damp Gravity
i50 0.0 10 3000  100 0.02 9.81
i50 . . .  90  . .
i50 . . .  80 . .
i50 . . .  70 . .
i50 . . .  60  . .
i50 . . .  50  . .
i50 . . .  40 . .
i50 . . .  30 . .
i50 . . .  20 . .
i50 . . .  10  . .
; Pendula
; Sta Dur Amp PendL Damp Gravity
i50 10.0 10 3000  100 0.02 9.81
i50 . . .  95  . .
i50 . . .  90 . .
i50 . . .  85 . .
i50 . . .  80  . .
i50 . . .  75  . .
i50 . . .  70 . .
i50 . . .  65 . .
i50 . . .  60 . .
i50 . . .  55  . .
; Pendula
; Sta Dur Amp PendL Damp Gravity
i50 20.0 5 3000  200 0.1 9.81
i50 . . .  100  . .
i50 . . .  50 . .
i50 . . .  25 . .
i50 . . .  12  . .
i50 . . .  6  . .
; Pendula
; Sta Dur Amp PendL Damp Gravity
i50 25.0 5 3000  100 0.05 9.81
i50 . . .  90  . .
i50 . . .  81 . .
i50 . . .  73 . .
i50 . . .  66  . .
i50 . . .  59  . .
i50 . . .  53 . .
i50 . . .  48 . .
i50 . . .  43 . .
i50 . . .  39  . .
</CsScore>
</CsoundSynthesizer>

Planar Crystal Live Rig

Demo of the rig.

Planar Crystal Live Rig

My planar Crystal live rig consisting of Waldorf Pulse processed by Lexicon Vortex, Korg MS2000, MPC500 for sampling and sequencing, Thing 2 and Sequencer processed by Kaoss Pad.  Midi clock originates with MPC500 and controls arpeggiator speed on MS2k, Pulse, and KP3. I used Velcro to connect the Vortex to the pulse.

Mini Modular NAND

I have been thinking about the NAND synth and giving it some additional capabilities.  This is my plan for a mini modular based on the 4093 NAND.  Each of the four NAND gates would be made into a separate oscillator.  Each oscillator would have three switches three knobs/pots and three jacks.

Switch 1 On/Gate: Determines if it is on all the time or if it can be controlled by the gate input.
Switch 2 Square/Saw: Switches a capacitor on the Cv input (I need to add this cap to the circuit shown above.)
Switch 3 VCO/LFO: Switches the feed back to a larger capacitor to make it into an LFO.
Knob 1 Pitch
Knob 2 Volume
Knob 3 Modulation amount (pitch)
Jack 1 Gate input
Jack 2 Cv Input
Jack 3 Output

This is the basic schematic for this.  Assume the gate starts in state Hi Lo then the 1n cap charges until it goes Hi at which point the output goes Lo.  The rate of charge and discharge is controlled by the pitch pot or by the transistor depending on the base current.  The LED monitors the output and turns on or off based on the output.  The LFO switches in a larger capacitor so it takes longer to charge.  The wave shape applies a low pass to the input signal.  I may have made some mistakes in this drawing but this is basically how it works.

This basic structure is repeated four times.

Next comes the filter which I described in a previous blog.  This consists of three simple resonant low pass filters and a clipping op amp differentiator.

This one does not have the voltage control transistor in it yet so I am still working on that.  It also shows a QF connection on filter 2 which should be bypassed.  The way this filter works is to have both a resonant low pass (with assymetry switch) and a low pass (Q turned all the way down).  Then subtract the two signals and clip them with the op amp.  This creates a complex waveform (supposedly).  Finally feed the result out through the final filter with resonance.  Need to add an additional input for external signals as well as transistors so I can modulate the cut off frequency.  The filter will from the base of the module.

RS is a rail splitter.

Planar Crystal 020

The planar crystal is a device which can transport someone spatially, temporally, and inter-dimensionally upon touching.  Those who touch it accidentally may wander the multiverse searching for the way home.


Motif ES7 with PLG-150DX (used for Skrillex sounds, Waldorf Pulse, Dune (Plug-in), mixed in Reaper, Kicks from Pulse and Little Phatty, some effects using Lexicon Vortex.  Drums using BFD Eco and MPC500.  Sound effects include home made electronic drones, filter modulated bulldozer samples and glitched effects.  Audio damage Replicant, Michael Norris Drone and glitch plugins.  Final noise sweep is a Thing 1 Noise generator modulated through a Korg EMX1.  Vocals recorded with DP004 digital recorder and modified using Michael Norris FX and Replicant.  Voxengo Elephant used for mastering compression.  EHX Stereo Talking Machine used on arpeggios near the end to give vocal effects.