Review of 3 Leaf Audio Proton Envelope Filter Review
Dan Veall was so carried away with 3Leaf's GR2 (reviewed in issue
9) that we gave him another from the Seattle wonders, just to watch
his little red eyes light-up with joy!
After the fun I had with 3Leaf's GR2 in our previous issue I've
been given another of the company's envelope filters to try this
time, but this one based on another legend of the Funk world. I'm
pretty sure 1970s Funk and Soul music wouldn't be the same without
this characteristic sound. A bit of Bootsy anyone? Stevie Wonder
and Jerry Garcia, amongst others, also helped make the Mu-Tron III
envelope filter famous. Mu-Tron's beast of a pedal was another that
ate up pedal board real estate and didn't make life easy for
guitarists, as it needed its own special power supply (and a
suitcase to house it in!). Spencer Doren of 3Leaf Audio has taken
the design of the Mu-Tron and in his view improved it, as well as
treated it to a serious diet. Once again, he has managed to squeeze
a beast of a box in to a small case. In fact, this time it's even
smaller than the GR2 Groove Regulator.
The fewer controls of the Proton in comparison to the GR2
certainly does not mean there is any less flexibility in terms of
available sounds, though. In fact, the Proton, like the GR2, is
packed with useful and epically funky sounds!
I feel the sign of a great boutique pedal designer is to know
what features are needed and useful while not 'over-cooking' things
unnecessarily with too many bells and whistles. This could also be
said about great amplifier manufacturers. Cluttered knob layouts
lead to confusion. Most bass players like to keep things relatively
simple, I think, and for that reason the Proton will be welcomed
with open wallets - simplicity, ease of use and overall great
Like the GR2, the top left control is the 'sensitivity' but on
this model it is labelled Gain instead. I think I prefer that as a
name as it is controlling the level in to the filter circuit. Too
low a level and the filter won't affect the signal. The Proton
doesn't have the attack and decay controls of the Groove Regulator,
however adjusting the Gain control does affect those functions as
you advance the knob clockwise. Experimentation is needed to find
that point on the dial that nails the sound you are after. Again,
like the GR2, switching to a bass with a different output level may
mean that you'll need to readjust this control.
To the right hand side is the Peak knob - this could be
described as the effect resonance, or the 'depth' of the effect. I
found that lower settings were subtle and much higher settings
delivered an effect that would cut through any band mix. In some
cases a few ear drums too! I'm sure this would have sounded
fantastic daisy-chained with a distortion pedal connected after it
(placing a distortion pedal after a pedal that relies on signal
dynamics instead of before will ensure a stronger effect from the
dynamic pedal. Distortion pedals compress the dynamic range on
higher gain settings so if placed before can mean that the dynamic
effect is subdued.)
Three switches below the two knobs include: Range, which
controls the frequency range of the filter sweep - great for using
with either bass or guitar, you can switch to the range that has
the strongest effect or indeed, whichever you prefer! Moving on to
the range switch, which again, like the GR2, toggles between a band
pass mode that focuses the effect more aggressively in a specific
region but loses low end. Or there is the low pass mode that allows
low frequencies through the pedal as well so that the signal
remains full. There's nothing worse than disappearing from a mix,
swallowed up by the volume of other instruments when your low end
disappears! The last switch on the front panel reverses the
direction of the sweep effect. 3Leaf Audio suggests raising the
gain control a little to make the effect more pronounced.
Having both of these pedals in at the same time for review was
pretty exciting and I am pleased to report that they delivered
signature funky tones. It was easy to get great sounds and I feel
that even a novice to envelope filters would be grooving very
quickly with either of these models.
Which one is for you? Well watch the video here and check-out
iGuitar 9 to hear the GR2! To me, both are fine boutique pedals and
which you choose will depend on your ears!
Check out the full review inc. video of the 3 Leaf Audio Proton
Envelope Filter the by Dan Veall featured in Issue 10 of
Guitar Interactive Magazine (
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