The Mastro Valvola Lysergic Emotions Module (LEM) is a multi-head delay pedal from the Italian maker Mastro Valvola, with eight effect modes designed to inspire dreamy and experimental ambiances1. It is built around an old delay unit, the LEM, manufactured in Italy, and emulates a multi-head tape delay2. Mastro Valvola announced the pedal in December 2019, when it was available for pre-order at €2903.
A multi-head delay with reverse and reverb ambience
The LEM offers up to eight ambience types, ranging from a standard reverse delay to a lo-fi spatial ambience delay-reverb3. Pedal of the Day's reviewer found that "it's easy to run into unique, hypnotic or unexpected sound environments like shimmering repeats, [reverse delays], multi"1, describing sounds that run from shimmering repeats and reverse delays to multi-head modulations, pitch shifting and lo-fi sounds1.
The front panel carries four knobs for wet/dry, delay and feedback3:
| Control | What it does |
|---|---|
| Wet/Dry | Separate dry-wet control over the balance between your clean signal and the effect3 |
| Delay | Lets you input the delay time2 |
| Feedback | Controls the number of delay repeats2 |
| Special | Each mode has a special effect controlled by the Special knob2 |
| EXP/CV | Sets which parameter is controlled externally2 |
| Shift | Allows you to access alternate functions of certain parameters2 |
External control and bypass options
The LEM has a CTRL input, which supports either an EXP/CV connection or a remote switch for managing different functions of the pedal3. External and CV control add more options into the mix, as Pedal of the Day put it1, and the EXP/CV knob decides which parameter that external input drives2.
Bypassing works two ways: the pedal offers true bypass and a Timed Bypass System (TBS)3. The Bypass footswitch functions in both latching and momentary modes, letting you decide if you want the effect on all the time or only while the switch is held2. TBS can be toggled in conjunction with the Shift button to allow for trails, where the delay effect persists and decays naturally after the effect is turned off3.
The right footswitch toggles between the pedal's stored presets, so the two footswitches split duties between preset selection and bypass3.
Presets
Up to four presets can be stored within the LEM, and Pedal of the Day counts 4 on-board presets as well as the secondary control section13. Presets can be toggled via the right footswitch3.
Videos
aBunchOfPedals
Ponderer Sounds
Mark Johnston
Questions
Does the Mastro Valvola LEM have trails?
Yes. The pedal's Timed Bypass System (TBS) can be toggled in conjunction with the Shift button to allow trails, where the delay effect persists and decays naturally after the effect is turned off. The Bypass footswitch also works in both latching and momentary modes, so you can decide whether the effect is on all the time or only while you hold the switch.
How many presets can the Lysergic Emotions Module store?
Up to four presets can be stored within the LEM, and they can be toggled via the right footswitch. Alongside the presets there is a secondary control section on the pedal.
Can I control the LEM with an expression pedal?
Yes. The LEM has a CTRL input that supports either an EXP/CV connection or a remote switch for managing different functions of the pedal. The EXP/CV knob sets which parameter is controlled externally.
Is the Lysergic Emotions Module true bypass?
The LEM offers two bypassing options: true bypass and the Timed Bypass System (TBS). True bypass removes the effect from the signal path entirely, while TBS allows trails so the delay repeats persist and decay naturally after the effect is turned off.
What does the Special knob do on the LEM?
Each of the pedal's eight modes has a special effect controlled by the Special knob, so what it does depends on the ambience type you have selected.
Sources (3)
- Mastro Valvola LEM Lysergic Emotions Module Delay, Pedal of the Day, 2025-04-01
- A tape delay pedal with vintage vibes: Mastro Valvola's Lysergic Emotions Module, gearnews.com, 2019-12-23
- Mastro Valvola gets ethereal with its LEM delay pedal, guitar.com, 2019-12-23
