Hungry Robot The Lumen state variable overdrive

The Lumen is a State Variable FET-Based Overdrive.  It marks a return to the overdrive world for Hungry Robot Pedals.  

Under the hood, it contains an active State Variable Filter, a type of filter that is common place in the synth world.  State Variable Filters offer more clarity and presence than standard passive tonestacks.  A typical passive tonestack works by removing tonal content, a State Variable Filter works by actively amplifying frequencies that are already present in your signal.  The filter is actually made up of 3 individual filters (low pass, band pass, high pass) that split the incoming signal into 3 frequency ranges and amplifies those ranges without tone loss.    

While designing The Lumen, I challenged myself to create an overdrive that used no diode clipping.  The most common approach for an overdrive is to send an amplified signal into a clipping section where diodes chop up the waveform and distortion is create.  I opted for a more natural approach of cascading FET gain stages.  The distortion is created by soaking the transistors with gain.  To me, this method provides a more organic, tube-like saturation than a clipping section.  

And to top it all off, The Lumen also has a clean blend, allowing you to mix back in some of your clean tone.  At 12 o'clock, the clean signal is near unity gain.  Past 12 o'clock, it amplifies your clean signal. 

​Knobs

“Drive” – Sets the gain level on the first FET stage.  It is normal for the knob to crackle when turned.

“Clean” – Sets the level of the clean blend.  Past 12 o'clock is boost.  

“Level” – Sets the volume of the drive signal.

“H.P” – Sets the level of the high pass filter.

“B.P” – Sets the level of the band pass filter.

“L.P” – Sets the level of the low pass filter.