FX72 Bass Stereo Flanger

The first and the last cosmetic variants of the FX72 Bass Stereo Flanger, from 1988 (left) and 1994

The FX72 Bass Stereo Flanger was derived from the FX75-B Stereo Flanger, but voiced for bass guitar. Like the FX75-B, the FX72 is an analog flanger, using a MN3007 BBD chip. The FX72 debuted in late 1987 and remained in production until 1996.

• Controls: Delay (1-12 milliseconds), Speed (0.8-8 Hz), Width, Regen
  
  
• From the manual (1987, shared with the FX75-B): "The FX75B and FX72 delay the input sound and then mix the delayed and original sounds together. The DELAY time control adjusts the amount of delay time in conjunction with: the WIDTH control which sets the range through which the delay time may vary, and the SPEED control which adjusts the rate at which delay time changes. The REGENeration control adjusts the height of the comb filter peaks by controlling feedback through the delay circuitry. The REGENeration control allows the adjustment of the effect from very subtle to very pronounced."
  
  
• Technical info:
  
  
  • Specifications (1987): Input impedance = 500 k Ohms, Output impedance = 1 k Ohms; Bandwidth = 40 Hz-16 kHz; Gain = 0 dB; plus the Delay Time Range and Sweep Speed listed above
    
    
  • Notable IC chips: MN3007 BBD chip driven by a MN3101 clock generator/driver CMOS chip; one TL022CP and two 1458-type op amps (early versions) or one 358-type and two 1458-type op amps (later versions)
    
    
  • Internal trim pots: three; however, we do not recommend messing with trim pots
    
    
  • Component-side circuitboard images: June 1988 June 1994
    
    
  • Related circuit: FX75-B
  
  
• External links:
  • @ ftp.dod.com - instruction manual (1987), .pdf format
  • @ discofreq's FX site
  • @ harmony-central.com
  • @ noiseguide.com
  • @ ultimate-guitar.com
  
  

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