WMD Effects Protostar Interstellar Envelope Filter

$ 399.00

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WMD Effects Protostar Interstellar Envelope Filter

The Protostar is the evolution of the Super FatMan envelope filter with even more pro level features.  Built in LFO, 4 filter modes, full CV patch bay, and expression/CB input, this is the most powerful/versatile envelope filter on the planet.  Also includes an end of chain compressor and dry wet mix for parallel filtering/compression effects!


Attack - How fast the envelope will react to the incoming signal. Controls both
attack and release.

Threshold - How sensitive the envelope is to the incoming signal.

Env Amt - Attenuverter that controls how much the envelope will affect the frequency of the filter, either negatively or positively.

Resonance - Synonymous with feedback or Q, this is a boost of the frequencies around the frequency cutoff.

Freq - Also known as cutoff, this knob’s position dictates the resting place of the
frequency cutoff. 

LFO Rate - Make the LFO go faster or slower with this knob.

LFO Amt - How much the LFO will affect the frequency cutoff.

Compression - End of chain compressor squashes the wet signal to suppress unwanted honks, and resonant oddities.

Dry / Wet - Amount of unaffected vs. affected signal coming through the output.

Sidechain - Direct input to the envelope follower. Normalled to the input, use this to have the envelope follow an external source.

Exp Out - Output for the expression pedal input. Exp isn’t connected to any control internally and must be patched.

- Env Out - Always sending +5V until the envelope is triggered, bringing the voltage down to 0V and back.

+ Env Out - Sends a CV signal following the envelope. Signal is 0V to +5V.

LFO Out - Constantly sends the triangle wave LFO CV signal, reacts to LFO rate knob.

LFO Rate - CV input for control over LFO rate. Sensitivity adjustable with internal trim pot.

LFO Amt - CV input for control over LFO amt.

Freq - CV Input for control over cutoff frequency.

Feedback - CV input for control over resonance.

Expression Input (back panel) - Plug a TRS cable from any expression pedal into this, patch the exp out to what you want to control, and express yourself.


  • Power: 9VDC, Boss Style Center Negative, 400mA. 1A supply recommended. Do not exceed 9V.
  • 1A supply recommended.
  • Internal Bipolar 12V power supply.
  • 0-5V nominal CV range. All inputs/outputs protected.
  • LFO CV sensitivity and Compressor Gain adjustable internally.
  • Relay true Bypass.
  • Expression Pedal: 10k - 1M pot. TRS connection.
  • Patch Points - Mono or Stereo cable. Signals are mono.
  • Dimensions: 4.9" x 3.9" x 2.4" 
  • Every WMD product is warranted for 12 months after purchase, but please contact us if you ever have problems. We will take care of you
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    Vendor: WMD Effects
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