The Flamma FC21 Analog Comp is a compact compressor pedal that uses an optical circuit, the same basic approach as classic studio compressors built around a light source and a light-dependent element. Flamma describes it as providing "that classic, optical compression while maintaining a smooth attack and decay," tuned for a sensitive dynamic range1. It sits in Flamma's FC line of mini pedals, and it is closely related to another mini pedal: Delicious Audio called it "a repackaged but cheaper (and better looking) version of the Mooer Yellow Comp"2.
For a player, that means a small-format compressor with three knobs, an analog signal path, and true bypass, aimed at evening out dynamics without obvious pumping. Flamma's own shop page currently lists the pedal as sold out1.
An optical mini compressor
The FC21 is an analog pedal, and its compression comes from an optical circuit rather than a voltage-controlled amplifier or a FET. Flamma's product page frames the goal plainly: classic optical compression with a smooth attack and decay, tuned specifically for a sensitive dynamic range, with EQ and volume knobs that allow customization of the effect1. Pedal of the Day echoed the same description when the pedal appeared in December 2022, calling it "a simple effect that takes your tone to the next level"3.
The pedal shares the FC line's standard build: a compact, metal shell with true bypass when not engaged1. Both Delicious Audio and Pedal of the Day reported the same enclosure and switching when they covered it23.
What the knobs do
The control set is minimal, three knobs in total2:
| Control | What it does |
|---|---|
| Compression | Sets the amount of gain reduction2 |
| EQ | Shapes the tone; Flamma says it allows customization of the effect1 |
| Volume | Sets the output level1 |
There are no attack, release or ratio controls; the FC21's controls are Compression, Volume and EQ. That is typical of mini optical compressors in this format, where the circuit's inherent attack and release behavior does that work and the player adjusts amount, tone and level2.
Optical versus VCA and FET designs
Optical compressors work differently from the VCA and FET designs used in many other pedals. As Delicious Audio explains:
"Optical compressors are based on a technology that produces slightly different compression from regular designs (normally VCA or FET)."2
For a player choosing between compressor types, that slower, smoother action is the practical difference: an optical circuit tends to glue dynamics together without the faster, more aggressive grab of some VCA-based pedals. Flamma leans into this character, describing the FC21's attack and decay as smooth1.
A variant of the Mooer Yellow Comp
The FC21's circuit lineage runs through the Mooer Yellow Comp, an optical mini compressor that MOOER introduced in a full metal shell with a very small and compact design24. Vintage Guitar reported on the Yellow Comp's introduction in 2013, noting its metal housing and true-bypass wiring5. Delicious Audio's verdict on the Flamma version was direct:
"a repackaged but cheaper (and better looking) version of the Mooer Yellow Comp"2
The FC21 is part of the Chinese company's FC line of mini pedals2, and Pedal of the Day described it as a repackaged but cheaper and better looking version of the Mooer Yellow Comp2. Players comparing the two will find the same basic recipe in both: a compact, full metal shell optical compressor with a very small and compact design14.
Videos
Flamma Innovation
Pedal of the Day
Ryan Lutton
Questions
Is the Flamma FC21 analog or digital?
It is analog. Flamma lists it as the FC21 Compressor Analog Comp, and both Delicious Audio and Pedal of the Day describe it as an analog optical compressor. The optical circuit uses a light-dependent element to control gain reduction rather than digital processing.
Is the Flamma FC21 true bypass?
Yes. Flamma's product page states the FC21 has a compact metal shell with true bypass when not engaged, and both Delicious Audio and Pedal of the Day report the same. Your dry signal passes through untouched when the pedal is off.
What is the Flamma FC21 based on?
It is a repackaged version of the Mooer Yellow Comp. Delicious Audio called it a repackaged but cheaper and better looking version of the Mooer optical compressor, built in the same compact metal mini-pedal format.
How is an optical compressor different from VCA and FET designs?
Optical compressors use a light source and a light-dependent resistor to control gain reduction, which produces slightly different compression from regular VCA or FET designs. Delicious Audio notes they typically have a slower attack and release and can be very transparent, with a smooth attack and decay.
What do the knobs on the FC21 do?
There are three knobs: Compression sets the amount of gain reduction, Volume sets the output level, and EQ shapes the tone. Flamma says the EQ and volume knobs allow customization of the effect, and the pedal is tuned for a sensitive dynamic range.
Sources (5)
- FLAMMA FC21 Compressor Analog Comp Classic, Optical Compression, Flamma Innovation
- Flamma FC21 Analog Comp, Delicious Audio, 2022-09-28
- Flamma Innovation FC21 Analog Compressor, Pedal of the Day, 2022-12-23
- Yellow Comp_MOOER Audio, MOOER Audio
- Mooer Intros Yellow Comp Optical Compressor, Vintage Guitar magazine, 2013-07-24
