Exar FL-1 Flanger [schematic]

All about modern commercial stompbox circuits from Electro Harmonix over MXR, Boss and Ibanez into the nineties.
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Post by VitaliiBobrov »

I traced Exar FL-1 Flanger from my collection ๐ŸŽ‰. The unit should have been made in 1989 or later due to the dates on the pots (09-89). I even have the box ๐Ÿ˜….
Exar FL-1 Flanger with the box
Exar FL-1 Flanger with the box
This trace was quite challenging due to amount of components on the small single-sided PCB.
Exar FL-1 PCB bottom
Exar FL-1 PCB bottom
Exar FL-1 PCB top
Exar FL-1 PCB top
As I started, I immediately realized that it was based on... Boss BF-2. But when I went to the LFO section, it was completely different. So it is definitely "inspired" by BF-2 but has minor changes in component values on the signal path; LFO is replaced with something more similar to CE-2 (by overall structure but different values plus lowpass filtering); 741 op-amp is used instead of 78L05 regulator (most likely it wasn't available at that time in Poland). The "5V" power line on my unit was measured as 5.7V from 9.09V power supply. I also took an oscilloscope and measured the MN3102 clock. It varies from 36kHz to 450kHz, and LFO goes from 0.5Hz to 10Hz.
Exar FL-1 LFO
Exar FL-1 LFO
IMAGE1.png (8.81 KiB) Viewed 273 times
Attached is the schematic with buffered bypass parts omitted.

The op-amps used are Polish and Czech versions of pretty common ICs:
ULY7741 === LM741/uA741
ULY7722 === TL022
MA1458 === LM1458

Diodes BAYP-94A, BAYP-95 are 1n4148 alternatives.
Exar FL-1 schematic
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