3 Leaf Audio GR2 Envelope Filter

Published 12 years ago on May 1, 2012

By Guitar Interactive Magazine

It's not just guitarists who are being tempted by a growing number of boutique FX pedals - bassists are too. But how about a pedal you can use with either? We let Dan Veall loose on the 3 Leaf Audio GR 2.

Spencer Doren is the 'one man band' mastermind behind 3 Leaf Audio, the company he started in 2008 offering pedals made 'by a musician, for musicians'. We borrowed two units from our good friends at the UK bass specialist Bass Direct -  a GR2, which we're reviewing in this issue, and the Proton Envelope Filter, which we'll be featuring next time.

The GR2 'Groove Regulator' is derived from the legendary Lovetone Meatball pedal. Those who familiar with the original pedal will know that it was quite the beast in physical size. Put it this way, you'd never trip having not noticed it under foot! Spencer has designed his version of the Meatball pedal from a 'less is more' standpoint. It makes sense as there's a lot of hardware to shoe horn in to such a small box in order to retain those classic soundsandstill have enough room for a 9v battery!

Speaking of controls, I've demonstrated the range of different sounds available on our video and have saved the detailed descriptions for the written part of the review. So if it's the sounds you want to hear - click the video first!

First up, the GRs's sensitivity should be set with reference to the output of your instrument. I found that with my own custom bass that has a very high output, I needed to back the 'gain' down quite a way to the point where the filter had more of an effect. You can see this in more extreme settings in the video. The control can be likened to that of an amplifier gain control.

When you have set the sensitivity control, both the Attack and Decay knobs decide the length of the sweep of the envelope effect. The attack knob adjusts the initial response of the filter and the decay controls how long the filter takes to sweep the note. 3Leaf Audio suggests making sure the decay is set higher than the attack to allow the filter to be more effective. The decay control rewards the player with either short filter blips all the way up to long sweeps. The tone control is self explanatory and allows the overall pedal tone to be controlled much like that of a tone control on a guitar.

Underneath in the centre is the wet/dry effect mix, useful for adding some dry bass in to the mix at the GR2's output. In application, the GR2 is equally at home on guitar as well as bass. Flicking the range switch allows the filter to act on lower frequencies suited to bass or for high frequencies suited better to guitar. On the far right side the sweep switch. This simply reverses the direction of the sweep effect. A little time should be spent readjusting the other controls that interact with the sweep switch as it may not be immediately noticeable what the difference in some settings when switching back and forth. Something we noticed in the studio!

If that wasn't enough to be getting on with, Spencer has included some extra features in newer models. You'll find these 'under the bonnet' by removing the bottom of the metal case. First up, a 'low pass/ band pass' switch that changes the character of the filter. The Low Pass setting retains all of the instrument low end as part of the output whereas the 'band pass' setting focuses the effect sound in the mid and treble ranges and thus low end is subdued. This would be a good setting if you were mixing a clean signal with the low end intact elsewhere in the signal path. Up next, referencing the included manual, a RES+/RES- switch offers an adjustment for a more resonant sound or less so in the two different positions. There's a gain trimpot for boosting the signal from the filter should that be needed also. Finally for the internal controls the ability to switch between true bypass and buffered bypass modes. This is very handy for signal integrity and this is covered in more detail in the manual.

We've looked at the actual controls and sounds, and the obvious In, Out and power connections in the video but there's also an 'effects loop' which is a little unusual on a pedal. For those who are into experimenting with sounds and trying things out with other instruments, this is a great addition. Plug a drum machine or synth in to the input and use it to control the action of the effect, plug your bass in to the FX Return socket and the effect will be applied to the bass signal. You can of course use the send and return like a normal loop, so that you can switch on and off another pedal simultaneously when the GR2 is kicked on.

Power as mentioned, is via a 9v alkaline battery or from the standard 2.1mm centre-negative adaptor, 9-18v.

Soundwise, it's always difficult to describe in writing and I'd suggest listening to the video review through some quality speakers or headphones to hear what the Groove Regulator is capable of - better still, see if you can track one down to demo yourself. I really can't fault it - chock full of legendary sounds and built like the proverbial brick outhouse, it's a pedal with a boutique price tag, but I'd say that it's worth every penny. I can see this pedal being a favourite amongst funk'ers.

Ig9 Coversmall




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