I traced Exar FL-1 Flanger from my collection
. The unit should have been made in 1989 or later due to the dates on the pots (09-89). I even have 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 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
- IMAGE1.png (8.81 KiB) Viewed 276 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.
. The unit should have been made in 1989 or later due to the dates on the pots (09-89). I even have the box 
.