ELMYRA - Polyphonic drone/noise synth with sequencer/distortion/delay/modulation/filter
This is a METSÄÄN version of the ELMYRA synth by Neutral Labs, build in a recycled wooden box, painted black, with sheet metal bottom and a little side window, that let’s you see “the guts”, illuminated LEDs. Aluminum side brackets keep the face plate in place and add an extra ghetto-tek look. Even the touch pads are made from recycled thumbscrews found in an abandoned plumbing workshop. Handmade by GRM for METSÄÄN.
Elmyra is based on the Adafruit ItsyBitsy M0 Express micro controller. Its 10-bit audio resolution already gives it a wonderfully gritty sound, and this circuit adds some nasty analog distortion to it. Like in the famous LYRA8 the voices are played by the conductivity of your fingers. Touch the upper and lower pad at the same time to trigger a voice. Depending on the pressure and other factors, such as the resistance of your skin, the volume is increased or decreased. TUNE changes the frequency of the voices. This can be either a smooth change, or steps between notes, if in chromatic mode. SHAPE controls the oscillators waveform, one harsher (saw-ish) than the other. ENV changes the envelope attack and release length for this voice. TIME controls the delay time of the built-in delay. If the feedback is high,you can tune the delay time to generate new frequencies on top of the ones played by the voices. To facilitate this, the TIME knob is not linear: Its reaction is more sensitive at low values. FEEDBACK controls he amount of feedback for the delay. If your Elmyra won’t stop making noise even after the envelopes have rung out, and for some reason you want it to stop, turn this knob down. MIX, the dry/wet mix for the delay. At 50% setting, you’ll hear both the delay and the original sound at the same volume level. Turned up fully clockwise, you’ll hear only the delay. MOD, when turned up, this introduces a random modulation to the frequency of each voice, but unlike common LFOs this does not vary slowly over time. Rather, anew deviation value is chosen for each cycle of the waveform. The amount of deviation is controlled with this knob. Turned fully counter-clockwise, there is no modulation. FILTER, This is a low-pass filter that takes off some of the high range frequencies when turned down. You might want to leave this knob turned fully up by default and turn down as desired when the harshness introduced by the distortion or excessive filter feedback is too high for your taste. SCRATCH, this controls Elmyra’s nasty distortion. The circuit is built in such a way that a slight amount of distortion is present at all times, even if this is turned down. Turn it up to increase the nastiness. BITE, this switch will add high overtones and noise to the distortion. If the SCRATCH knob is turned down, it will have no perceivable effect. VOLUME controls the output volume.
Drone Mode: Flip any of the ENV switches twice quickly (within 1 second) to put the corresponding voice in drone mode, meaning that it will ring even if you’re not touching the touch pads.
Chromatic Mode: Flip SHAPE switch of voice 1 (on the left) twice quickly to enter chromatic mode. This mode is global and affects all voices. The frequencies selected by the TUNE knobs will now be in steps according to the chromatic scale, based on A4 = 440 Hz. The frequency range will be extended upwards. The MOD knob will still affect the voice frequencies as before.
Sequencer Mode (Recording): Flip SHAPE switch of voice 3 (on the right) twice quickly to enter step recording mode. This will delete any previously recorded sequence! The sequencer will record the TUNE frequency for each voice per step (only if this voice has its ENV switch in ‘up’ position), as well as the setting of the TIME knob for each step. Voices that have their ENV switch in ‘down’ position will not be recorded, which means you can use them to “solo” over your recorded sequence during playback. Touch the touchpads for voice 1. Make adjustments to the TIME knob and/or TUNE knobs as needed (you can touch the pads for voices 2 or 3 as well to check, or put them into drone mode during recording). When you release the pads for voice 1, the step is saved and you can start over with the next step in the same way. Up to 16 steps can be recorded. To leave recording mode, flip SHAPE switch 3 twice again, or alternatively enter playback mode directly by flipping SHAPE switch 2 twice.
Sequencer Mode (Playback): Flip the SHAPE switch of voice 2 (in the middle) twice quickly to enter playback mode.The voices will now play back their recorded TUNE values step by step and the TIME settings will be updated as well with each step. The voices will not be triggered automatically! In order to hear the sequence, you need to put voices into drone mode by flipping their ENV switches twice, or alternatively play them manually via the touch pads. The TIME knob controls the sequencer speed in this mode. Exit playback mode by flipping SHAPE switch 2 twice, or alternatively, enter recording mode directly. With some practice, you’ll be able to use recording and playback mode on the fly without interrupting your performance.
The synth runs on USB power, so you can use an old phone charger, your computers USB connectors or a power bank. USB > ELMYRA power cable included.
Please read the full manual, that explains all the functions here.
Output: 6.3mm / 1/4″ mono TS socket
Power: 5V DC (USB power cable and euro-jack powersupply included)
