Sputnik Modular EF/Preamp

The EF/PREAMP is an envelope follower with a built-in instrument / mic preamplifier and includes the following features:

Switch between instrument or mic input
Preamp output is normalled to input of envelope follower
Signal input with manual sensitivity control
Manual decay control for CV output
Pulse output responds to change in signal level and activity is indicated by LED
Sustain or transient switch for pulse response/behavior (gate)

The SPUTNIK ENVELOPE FOLLOWER/PREAMP is a dual function module that allows audio signals to be brought up to proper levels to be sonically manipulated by other Eurorack modules or to be converted into control voltage. The preamp section includes a balanced ¼” TRS cable input jack that can accept sound sources such as microphones, guitar pickups, keyboards, drum machines, etc. Three selectable gain modes are available via a switch with an additional gain knob to dial in the signal to the exact level you need. The envelope follower section of the module features an input jack for modular level signals and outputs for CV and pulses. Front panel knobs give you control over input sensitivity and CV envelope decay time.

ENVELOPE FOLLOWER

INPUT
Eurorack modular level audio input (10V p2p). If no input is present, the output of the preamp section is normalized to the envelop follower input.

PULSE OUTPUT
Outputs a 5V pulse when the CV level (after the Sensitivity attenuator) exceeds approximately 2.5V. Pulses may trigger envelopes, sequencers, or pluck a low pass gate.

CV OUTPUT
Outputs a CV value (between 0 to +10V) based on the amplitude of the audio input. Allows audio to control any number of CV parameters on Eurorack format modules.

SENSITIVITY
Acts as an attenuator for the incoming audio signal, allowing hotter signals to be brought down below the pulse output threshold. Simultaneously acts as a range control for the envelope follower’s CV output.

DECAY
Controls the decay of the CV output. A lower setting allows for a quick CV response that matches the audio input while a higher setting allows for more of a slew between amplitude peaks.

PULSE RESPONSE
This switch selects between two pulse response modes. Transient mode produces short pulses based on the CV output rises above approximately 2.5V. Sustained mode produces sustained pulses that are held at 5V when the CV output is higher than a ~2.5V threshold.

PREAMP

GAIN ATTENUATOR
Controls the amplification of the input signal. At fully closed the incoming signal will be completely silent and at fully open the maximum amount of gain will be applied.

INPUT
¼” TRS balanced instrument input jack.

GAIN MODE
Three gain modes (low, medium, high) are selectable based on how much amplification your audio input requires. Gain is applied after the Gain Attenuator.

IMPEDANCE
Two position switch for Mic mode for balanced signals (such as microphones) or Instrument mode for unbalanced signals (guitar, bass, or line-level audio such as keyboards or drum machines).

OUTPUT
Amplified audio output.