May 26, 2022

6 Tricks with the Mastro Valvola LEM and a TRS Footswitch.

While LEM creates some amazing sounds on its own, plugging in a passive TRS footswitch (like the Malekko Lil Buddy) will give you unique control over parameters without having to stoop down in the middle of a set and tweak a knob. This article shows you 6 tricks for LEM and an external footswitch with demos of how they sound.

What the heck is LEM?

The Mastro Valvola LEM Lysergic Emotions Module kinda defies description. When you first hear about it, you might think it’s a modern twist on Jimi Hendrix effects, but it’s not just that. It’s a multi-head delay, but goes well beyond YABEC (Yet Another Binson Echorec Clone). You’ll hear more in the demos below, but the key takeaway of LEM is that with the filters, bitcrushing, modulation and pitch-shifting, none of the eight programs will give you anything close to a normal delay.

What’s a Lil Buddy?

Gawd, do I hate that name. The Lil Buddy is a passive footswitch built for Malekko’s Sneak Attack and Goatkeeper pedals. At $35, it’s a cheap, simple momentary footswitch. It’s tiny, requires no power and is useful for footswitch-based expression when plug it into LEM with a stereo TRS cable.

When the Lil Buddy is plugged into LEM with a stereo TRS cable, you can control 6 different knob parameters. None of LEM’s settings are affected until you press or release the external footswitch. When you hold the footswitch it will max out whatever knob its set to control. When you release it, it returns to the knob position. There are other TRS, tap-tempo footswitches that may also work, but all the effects below have been tested and work with the Lil Buddy. (Gawd, do I hate that name. Did I mention that?)

Note: The effects on the demos have been cranked so it’s obvious what’s happening. All demos were recorded with just a Beat Root Multiscale tongue drum. No reverbs or other effects were exploited in the making of these demos.

1) The Space Echo Twist effect.

Top of the list is the ability to bend the LEM’s delay length and pitch with an external footswitch, similar to how the Roland Space Echo does. For this demo I used program 4) Multi.

  1. Plug a TRS stereo cable between the Lil Buddy and the LEM Cntrl jack.
  2. On LEM: Set the Exp/CV toggle to Delay.
  3. Set the Wet and Dry knob positions to 2p.
  4. Set the Delay knob to to 12n.
  5. Set the Feedback knob to 3p.
  6. Set the Program and Special knob to taste.

Now when you hold the footswitch, the delay goes to full length and shifts down in pitch, then corrects itself. When you release the footswitch the delay will shorten and pitch back up to the knob position. The delay will always extend to maximum length when you hold the footswitch, but you can set the start position with the delay knob. If you want a more drastic shift, set the Delay knob to 7a. If you want a mild pitch shift set the Delay knob between 3-4pm.

2) Sustaining the delay.

This is really useful and maxes out the Feedback knob. The feedback will raise to unity except on programs 6) Lo-fi Amb and 8) Shim where it can self-oscillate. For this demo I used program 8) Shim.

  1. Plug a TRS stereo cable between the Lil Buddy and the LEM Cntrl jack.
  2. On LEM: set the Wet and Dry knob positions to 12n.
  3. Hold the Shift button and set the Exp/CV toggle to Feedback.
  4. Set the Feedback knob to 12n.
  5. Set all other knobs to taste.

Now when you hold the footswitch the feedback maxes and when you release it subsides. On programs 6) Lo-fi Amb and 8) Shim try setting the Feedback knob to 9a and engage the external footswitch a few seconds after you stop playing to subtly fade in the self-oscillation.

3) Intensifying vibrato and wow.

This trick controls the depth of vibrato and wow when they’re controlled by the Special knob. On this demo I used program 1) Reverse.

  1. Plug a TRS stereo cable between the Lil Buddy and the LEM Cntrl jack.
  2. On LEM: set the Wet and Dry knob positions to 2p.
  3. Hold the Shift button and set the Exp/CV toggle to Spec.
  4. Set the Program to 1) Reverse, 2) LFO Rev or 4) Multi
  5. Set the Special knob to 9a.
  6. Set all other knobs to taste.

Now when you hold the footswitch, the vibrato or wow depth will max into wooziness. Let it go and it returns to normal. The speed is controlled by the setting of the Delay knob.

4) Speeding up the 4-pole filter.

The Special knob controls the rate of the 4-Pole filter on the 3) LFO Rev program. The external footswitch can turn a slowly-sweeping wah into a wubbling mess.

  1. Plug a TRS stereo cable between the Lil Buddy and the LEM Cntrl jack.
  2. On LEM: set the Wet and Dry knob positions to 2p.
  3. Hold the Shift button and set the Exp/CV toggle to Spec.
  4. Set the Program knob to 3) LFO Rev.
  5. Set the Special knob to 9a.
  6. Set all other knobs to taste.

When you hold the external footswitch the rate of the LFO filter will max. Where the Delay knob is set will have a strong effect on the sound.

5) More better bitcrushing.

Another unique feature to put on a delay is a bitcrusher. On the effects with bitcrush, the Special knob controls lowers the bit depth. For this Demo I used program 8) Shim.

  1. Plug a TRS stereo cable between the Lil Buddy and the LEM Cntrl jack.
  2. On LEM: set the Wet and Dry knob positions to 2p.
  3. Hold the Shift button and set the Exp/CV toggle to Spec.
  4. Set the Program knob to 5) Low Shim, 6) Lo-Fi Amb or 8) Shim.
  5. Set the Special knob to 9a.
  6. Set all other knobs to taste.

Holding the external footswitch will sweep the bitcrush in and letting it go returns bit depth to normal.

6) Jumping between delays.

On Program 7) Multi, the Special knob mixes between two delays: one forward and one reverse.

  1. Plug a TRS stereo cable between the Lil Buddy and the LEM Cntrl jack.
  2. On LEM: set the Wet and Dry knob positions to 2p.
  3. Hold the Shift button and set the Exp/CV toggle to Spec.
  4. Set the Program knob to 5) Low Shim, 6) Lo-Fi Amb or 8) Shim.
  5. Set the Special knob to 9a.
  6. Set all other knobs to taste.

When you press and release the external footswitch LEM quickly fades back and forth between the two head settings.

Bonus trick: Infinite sustain.

On some of the programs like 4) Multi, in Trails mode the delay can sustain pretty much infinitely after you bypass the LEM. This lets you play over top without Either turn the Feedback knob up to 5p or hold the external footswitch. With some fancy footwork you can disengage LEM while continuing to hold the external footswitch.

My take.

While an expression pedal works great with the Mastro Valvola LEM, it takes up a lot of pedalboard real estate and one more jack in your power supply. An tiny, passive, external footswitch like the Malekko Lil Buddy doesn’t even require much thought: you just tap and release it to warp the effect on LEM.

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