Bi-Filter

The Electro-Harmonix Bi-Filter is an analog, dual envelope follower utilizing multimode filters and a myriad of state-of-the-art features. It combines two versatile "all analog" envelope and LFO controlled filters in a configuration that enables the most complex and interesting filter sounds ever possible. The Bi-Filter continues the tradition of the original Mu-Tron, Beigel Sound Lab, and Electro-Harmonix Q-tron products by using opto-electronic "photo-mod" control. The "state-variable filter" architectures produce a clean and unique sound, with selectable filter curves preferred by top professionals. The Bi- Filter uses all analog circuitry, providing the best dynamic range and signal- to-noise characteristics of any available filter product. The effect circuit also uses "true bypass" switching to allow pure unmodified instrument throughput when the effect is switched off.

Key Specifications:
- Maximum Input Signal Level: 6.3 VRMS (+18 dBV)
- Maximum Control Voltage Input Level: 5 VDC
- Minimum Control Voltage Input Level: 0 VDC
- Maximum Signal Gain (Q Control = 10): 34 dB
- Minimum Signal Gain (Q Control = 1): 0 dB
- Sensitivity for Full Envelope Sweep: 1.0 VRMS (ENV Drive Control = 1) to 20 mVRMS (ENV Drive Control = 10)
- Filter Frequency Range:
- LOW: 150 Hz to 5 kHz Resonant Frequency
- HIGH: 350 Hz to 12 kHz Resonant Frequency
- Frequency Response (Dry Output): Beyond 20 Hz to 20 kHz ± 0.5 dB
- Dynamic Range (Measured at output): 105 dB best case
- Residual Noise Level: -93 dBV worst case
- Maximum Undistorted Output: +12 dBV worst case
- Sweep Oscillator (LFO) Rate Range: 0.02 Hz (50 s) to 30 Hz
- Envelope Attack Time: 5 milliseconds to 1.5 seconds
- Envelope Decay Time: 10 milliseconds to 1.5 seconds
- Envelope Voltage Output: 0 to 14 Volts