3 Leaf Audio Chromatron User manual

SPECIFICATIONS
POWER 9V DC, 30mA minimum. 2.1mm center-neg-
ative connector.
INPUT IMPEDANCE very high.
OUTPUT IMPEDANCE very low.
BYPASS transparent active bypass system with propri-
etary electronic switching. No clicks, no pops, will never
break.
FOOTPRINT 122 mm x 101 mm
The Chromatron is the result of 10 years tweaking, refining and reimagining the state variable filter circuit. It is an
optically-controlled analog filter that can switch between envelope control and manual control via expression pedal
with the push of a button. The envelope detector is an original design, producing a musical filter response that spans a
broad range of tones from vintage quack to future-synth psychedelica.
TIPS FOR GREAT TONE
A good starting point is to put the MIX knob full on, all
other knobs at 12 o'clock, RANGE and BAND down,
SWEEP up. From there, try turning each knob all the way
through its range and listen to the way the sound changes.
For a classic envelope filter sound, try short attack and
decay times.
Another fun setting is slow attack, fast decay and low
resonance, and setting the RANGE switch to the down
position. You can get sort of a slow gear-type sound with
this setting, where each note seems to apprear out of no-
where.
Octave and/or fuzz -> Chromatron is my favorite com-
bination, especially on bass. Use an expression pedal to
modulate the filter cuto for huge synth-like sweeps.
Chromatron -> distortion is great for psychedelic rock
tones. The resonant peak of the filter will accentuate the
distortion around cuto frequency.
Distortion -> Chromatron is perfect for dramatic, synth-
like filter sweeps. The filter will lop o the high frequen-
cies of the distortion as it sweeps down.
Chromatron -> delay is great for ambient textures, espe-
cially when using an expression pedal to sweep the filter.
Delay -> Chromatron is also very cool, as the delay re-
peats will be swallowed by the filter.

Plug your instrument into the INPUT jack and your amp into
the OUTPUT jack.
The FX SEND and RETURN allow you insert any number of
eects between the Chromatron's envelope detector and filter
sections. This is useful because - for instance - you could put
a volume-boosting distortion or dynamics-squashing fuzz into
the FX loop, and your clean signal at the input jack will trigger
the envelope detector while the filter is still last in the signal
chain.
Run a cable from fx send to the input of an eect, and run
another cable from the output of that eect to fx return. The
Chromatron is still triggered by the signal from the in jack, but
the filter aects the signal coming through the fx return jack.
This is particularly useful with dynamics-killing eects like fuzz.
The FX loop can also be used with external triggers. If you plug
your instrument into fx return, whatever is plugged into the in-
put jack will trigger the filter. You can use anything as an exter-
nal trigger; the possibilities are unlimited.
When the FX LOOP toggle switch is on, the pedals in the loop
will remain in your signal chain when the Chromatron is by-
passed. When o, the pedals in the loop are bypassed along
with the Chromatron.
The MODE footswitch toggles between envelope and expres-
sion control modes. Use a TRS cable to plug your favorite ex-
pression pedal (I recommend the Dunlop DVP3) into the EXP
jack and you can manually control the filter cuto frequency.
Only use an expression pedal with the standard voltage-on-
ring configuration.
In expression control mode, the RESPONSE, ATTACK and
DECAY knobs are disabled, and the TONE knob sets the cut-
o frequency when the pedal is all the way in the toe position.
RESPONSE is the sensitivity of the filter to your playing dy-
namics. Start with the sensitivity at minimum and turn up until
the filter responds to your liking. This is the most important
knob on the pedal!
ATTACK sets the speed at which the filter opens up. Lower
settings produce a fast, snappy attack similar to , while higher
settings produce a slow, fat “wah” sound.
In reverse sweep mode, ATTACK sets the minimum cuto fre-
quency of the filter.
DECAY sets the speed at which the filter closes back down.
Higher settings allow the filter to stay open longer, while lower
settings produce quicker, more “bubbly” envelope sounds.
TONE adjusts the maximum cuto frequency of the filter.
Think of it like the tone knob on a guitar.
MIX blends your clean input signal with the filter output.
RESONANCE sets the amount of feedback in the filter sig-
nal path. Higher settings produce a larger resonant peak at the
filter's cuto frequency, which makes the filter sound more
prominant. Be careful: higher resonance settings cause sharp
peaks that can damage speakers at high volumes.
BOOST is a post-filter gain stage.
RANGE sets the broad frequency range of the filter. Both
positions have been fine-tuned to sound great in a variety of
contexts.
SWEEP toggles between normal and reverse filter modes. In
the up position, the filter sweeps normally. In the down posi-
tion, the sweep is reversed. You may need to change the set-
tings of the attack and decay knobs for best results.
BAND toggles between low pass and band pass responses.
Down is low pass - a deep, full sound that retains all your low
end. Up is band pass - a more agressive sound that cuts low end
as the filter opens up. Try mixing in some clean signal in band
pass mode for a dramatic sound that retains low end.
WARRANTY The Chromatron is guaranteed against de-
fects for one year. The warranty covers the pedal under
normal use, not abuse. If you need to send your pedal in
for repair, send me an email.
[e-mail]
CONTROLSINPUTS/OUTPUTS