The Ibanez FL9 Flanger Service Guide was compiled from a collection of original and obsolete information to create a useful guide for maintaining this unique guitar pedal. Credit must be given to the authors of the original 1980s era Service Manual NO. 002 that was used as a template for this updated guide.

November 26, 2022, Cedar Grove Studios

The .pdf version of the guide and detailed repair blog can be downloaded from the project repository:

FL9 New Service Guide (.pdf)

FL9 Detailed Repair Blog (.pdf)

Also available is a KiCAD folder of the as-built PCB design, contained in the project repository:

FL9 PCB Reverse Engineered Design (KiCAD folder)

Block Diagram

Adjustment Procedure

CLOCK

1. Set SPEED, REGEN, WIDTH, and DELAY TIME controls fully counter-clockwise (CCW).
2. Connect an oscilloscope to test point CP1.
3. Adjust VR101 CLOCK TRIM for a frequency of 40kHz.
4. Set DELAY TIME control fully clockwise (CW) and check CP1 frequency. Should be in the range of 500kHz to 600kHz.
5. Set WIDTH control fully CW and check CP1 frequency sweep. The range should be from 40kHz to 500kHz-600kHz.

BIAS

1. Set REGEN and WIDTH controls fully CCW.
2. Connect a +5dBm to +10dBm (2.5 volt) 440Hz sine wave to the INPUT.
3. View the waveform on test point CP12. Adjust VR102 BIAS to achieve a symmetrically-clipped waveform.

REGEN

1. Set SPEED, REGEN, and WIDTH controls fully CW.
2. Connect an oscilloscope to the OUTPUT with no INPUT signal
3. Adjust VR103 REGENERATION TRIM until oscillation is seen. Back down VR103 REGENERATION TRIM about 10 degrees to squelch the oscillation.

Test Points

Test Point Signals and Voltages

Printed Circuit Board

Schematic Diagram

FL9 Schematic in the GitHub repository

Troubleshooting