Moog MoogerFooger MF-104M Analog Delay

Mix

The wet/dry ratio — how loud the delay repeats are relative to the dry (unaffected) signal. At minimum, the delay is inaudible and the signal passes dry. At maximum, the wet signal dominates. For most musical applications, setting Mix so that the dry signal remains clearly dominant (around 20–40%) produces a natural-sounding delay that adds depth without obscuring the original note. Higher mix settings create a more 'washed' effect where the delay becomes an equal part of the sound. For ambient and experimental applications, higher mix settings are appropriate.

Time

Delay time from very short (slapback) to 800ms. Short delay times (50–120ms) produce slapback — the classic rockabilly and country echo effect. Medium times (200–400ms) produce the quarter-note and dotted-eighth note delays that work well for rhythm-matched patterns. Longer times (500–800ms) produce ambient trails and wash effects. When using delay time musically, matching the delay time to the tempo of the song (using tap tempo or setting by ear) is critical — a delay that sits rhythmically produces one of the most effective uses of this effect.

Feedback

Controls how many repeats occur. At minimum, there is a single repeat. As feedback increases, the repeats multiply. Approaching 100%, the repeats sustain indefinitely. Past 100%, the delay self-oscillates — the feedback signal amplifies itself and the delay loop grows louder and more complex. The MF-104M's self-oscillation is particularly musical because the ladder filter continues to shape the character even as it sustains.

Drive

Input gain that adds warmth and mild saturation to the delayed signal. At low settings, the signal path is clean. As Drive increases, the input stage saturates gently, adding warmth to the delay repeats. This is one of the features that distinguishes the MF-104M from simpler BBD delays — the Drive control adds the slightly 'pushed' quality that makes the repeats sound more alive.

Filter

The ladder filter cutoff in the feedback path — controls how dark the repeats become with each pass. At maximum, the filter is fully open and repeats retain more of their original brightness. At lower settings, each repeat is progressively darker as the filter cuts high frequencies in the feedback loop. The classic MF-104M character uses moderate to low filter settings, where repeats warm and diffuse gradually — this is the most musically expressive aspect of the pedal.

Tap Tempo

Allows setting the delay time by tapping a footswitch to the beat. Essential for live use when the delay needs to be rhythmically synchronized. Tap twice or more to set the tempo, and the delay time adjusts to match.

LFO Rate

Controls the speed of the Low Frequency Oscillator that modulates the delay time. At slow settings the LFO produces a gentle, slow pitch wobble on the repeats — a subtle chorus-like shimmer. At faster settings the modulation becomes more pronounced and the pitch variation on the repeats becomes clearly audible. For most musical delay applications, keep LFO Rate slow (below 9 o'clock) to add subtle movement without making the repeats sound unstable. Faster LFO Rate paired with higher LFO Amount produces a dramatic warble effect suited for experimental and psychedelic applications.

LFO Amount

Controls the depth of the LFO pitch modulation applied to the delay repeats — how far the pitch deviates from the original with each modulation cycle. At minimum, the LFO has no effect even if LFO Rate is set. As Amount increases, the pitch wobble on the repeats becomes progressively more audible. Low Amount with moderate Rate produces a gentle chorus character on the repeats. High Amount with any Rate produces dramatic pitch warble. For most applications, keep Amount low (below 9 o'clock) unless the modulation effect is intentional. Amount interacts directly with Rate — always set Rate first, then dial in Amount to taste.

CV inputs

Control Voltage inputs allow external modulation sources — expression pedals, synthesizers, LFOs — to control the Mix, Time, and Feedback parameters in real time. This enables effects like gradually slowing down the delay time (creating a pitch-shift effect on repeats), sweeping the mix during a phrase, or using a synthesizer's LFO to create rhythmic delay variations. On a modeler, the CV inputs are not applicable to the digital simulation, but time and feedback can typically be assigned to expression pedals for similar results.