Combined voltage controlled amplifier and mixer design

I have decided to combine the voltage controlled amplifier and mixer modules from Music From Outer Space, into a hybrid voltage controlled mixer where each VCA can work either as an independent unit or the output can be added to a mixed output. The panning circuitry from the mixer has been removed and the audio output from 2 of the VCAs is fed directly onto the left and right audio buses.

There will be twelve VCAs in total grouped into pairs so that mono inputs can be fed into 2 seperate amplifiers to enable a panned stereo output.

Inputs for each 2-channel amplifier:

• 2x Audio inputs.
• 2x Control voltage inputs.

Outputs for each 2-channel amplifier:

• 2x Audio outputs.

Controls for each 2-channel amplifier:

• 1x Mono to stereo toggle switch - Enables mono signal to be fed into both channels.
• 1x Linear/Logarithmic scale toggle switch - Operates on both channels.
• 2x Level slider.
• 1x Add to mixer toggle switch.

Mixer output:

• 1x Mixed audio output. 

Push button toggle on/off circuit

This circuit can be used to toggle another circuit on or off by pressing a momentarily on push button.

 

The 40106 inverting Schmidt trigger and resistor-capacitor network on the left act as a switch debounce circuit to create a positive pulse on the J-K flip flop 4027, which toggles the output on or off. The circuit toggles as soon as the switch is pushed and retains its state when the switch is released. 

 

This can be modified to toggle when the switch is released by swapping the switch and the resistor capacitor network so that the switch pulls up to +V instead causing a negative pulse on the flip-flop.

 

 

An ever increasing list of films

Orson Welles

• Citizen Kane (1941) ***
• The Trial (1962) **** 

Ingmar Bergman

• The Seventh Seal (1957)
• Persona (1966) 

Luis Bunuel

• The Exterminating Angel (1962) ***
• The Milky Way (1969) **

Federico Fellini

•  8½ (1963) ***

Stanley Kubrick

• 2001: A Space Odyssey (1968) ***
• A Clockwork Orange (1971) ***

Andrei Tarkovsky

• Solaris (1972) ***
• Mirror (1975) **** 
• Stalker (1979) *** 

David Lynch

• Eraserhead (1977) ****
• The Elephant Man (1980) **
• Blue Velvet (1986) **
• Wild At Heart (1990) **
• Twin Peaks: Fire Walk with Me (1992) **
• Lost Highway (1997) ****
• The Straight Story (1999) **
• Mulholland Drive (2001) ****
• Inland Empire (2006) ***  

David Cronenberg

• Videodrome (1983) ***
• The Fly (1986) **
• Naked Lunch (1991) *** 
• eXistenZ (1999) ***
• Spider (2002) ***
• A History of Violence (2005) **
• Eastern Promises (2007) ** 

Alejandro Jodorowsky

•  Santa Sangre (1989) ***

Shinya Tsukamoto

• Tetsuo: The Iron Man (1989) ***
• A Snake of June (2002) ****
• Vital (2004) **  

Ethan Coen, Joel Coen

• Barton Fink (1991) *** 
• The Man Who Wasn't There (2001) *** 
• No Country for Old Men (2007) ** 
• A Serious Man (2009) *** 

Darren Aronofsky

• Pi (1998) ****
• Requiem for a Dream (2000) ***
• The Fountain (2006) ***

Paul Thomas Anderson

• Magnolia (1999) ***
• There Will Be Blood (2007) *** 

Charlie Kaufman

• Being John Malkovich (1999) *** 
• Eternal Sunshine of the Spotless Mind (2004) *** 
• Synecdoche, New York (2008) **** 

Christopher Nolan

• Memento (2000) **
• The Prestige (2006) ****
• Inception (2010) ***

Richard Kelly

• Donnie Darko (2001) ****

Park Chan-wook

• Sympathy for Mr. Vengeance (2002) **
• Oldboy (2003) ***
• Sympathy for Lady Vengeance (2005) ***
• I'm a Cyborg, But That's OK (2006) *
• Thirst (2009) *** 

Takashi Miike

• Gozu (2003) **** 

Guillermo del Toro

•   Pan's Labyrinth (2006) ***

Michel Gondry

• Eternal Sunshine of the Spotless Mind (2004) *** 
• The Science of Sleep (2006) ***

Voltage controlled oscillator design

12 voltage controlled oscillators built into a single panel, with 3 sets of common manual controls controlling the parameters of 4 oscillators each. Each oscillator can be individually controlled by the control voltage inputs.

Common controls where chosen to save as much space as possible enabling all 12 VCOs to fit into a 2U panel. This also allows for manual transposition of 4 oscillators simultaneously, allowing easy adjustment of tones where multiple oscillators separated in frequency by the control voltage inputs, contribute to a single voice.

Inputs for each oscillator are:

• 3x 1V/Oct logarithmic frequency control (CV1, CV2, CV3) 
• Linear frequency control (LIN)
• Hard sync (SYNC)
• Pulse width control for SQR output (PWM)

Ouputs for each oscillator are:

• Square (SQR)
• Ramp (RMP)
• Triangle (TRI)
• Sine (SIN)

Common manual controls for each set of 4 oscillators:

• Coarse frequency adjust
• Fine frequency adjust
• Pulse width 

The oscillator circuit is based on the Music From Outer Space VCO. The only additions to this is the control voltage distributers necessary for the common controls.

Front panel layout:

There was copper orange and blue flux, sparking gaps of white light.

One day a tiny little earthworm decided to glow blue. It grew to twice its size and shot hot sparks of blue plasma around.

It thrashed around violently in its own electrically generated mayhem. After a while the glow faded and all that remained was a black burnt carcass. After all that pain and suffering, all that grandeur and celebrity, it was still just a tiny earthworm, except that now it was dead and fried to the pavement.

- Excerpt from Idios Hodos