The Spectra Mirror’s T&H circuit captures and holds the voltage of an incoming audio signal every time a positive clock edge is detected. As soon as it disappears, the module stops processing the material and lets it pass through unaltered. Therefore, by varying the pulse width of the clock signal, the user is able to control how much of the sound is edited. The frequency determines how often a new “snapshot” is taken.
Spectra Mirror uses a pulse oscillator to create clock signals. Its frequency can range from 0.1 Hz to 22 kHz. Besides a potentiometer for manual rate adjustments, there are two FM inputs with attenuator respectively attenuator / inverter combination. A note jack allows the user to play the module over a range of four to five octaves with correct pitch. The clock signal’s pulse width can also be edited via a knob plus there are two more CV inputs with attenuator / inverter combination to influence the parameter. Alternatively to the internal oscillator, an external clock can be utilized. It is fed to the module’s comparator, meaning the pulse width options stay available.
The audio input offers a gain stage for level adjustments. A resonance potentiometer offers the possibility to return portions of the output signal back the input of the Spectra Mirror. Additionally, the module contains a bipolar VCA, which is controlled by a knob labeled Morph. It alters signal strength and polarity of the feedback loop. Again, there is a CV input plus attenuator / inverter combination for modulations.
Spectra Mirror comes equipped with four outputs. The first three emit signals derived from the Track and Hold circuit, the VCA and the internal oscillator. Output number four can be used to tap off a mixture of input and VCA signals. Combining the two leads to phase cancellations and high pass sampling sounds.
The first FM input is normalized to one of the pulse width CV channels and the morph control voltage input. This setup allows the module to mimic the behavior of a low pass gate.
Two FM and PWM inputs plus a morph CV input
3U Eurorack module, 18 HP wide, compatible with Skiff cases