Engines & sounds

SLOOP comes with 153 factory sounds, each a complete patch on one of the twelve The twelve engines. All of them are level-matched: two sounds at the same LEVEL play equally loud, so you can swap one bass for another mid-groove.

PRESETS steps through them on a synth track, sorted by kind, with the kind shown beside each name. Favourites come first, then the factory sounds, then your 32 user presets.

Every new project opens at 90 BPM: track 1 plays 808 BOOM, track 2 RHODES, track 3 LOFI FLUTE, and the drum track the 808 kit. SAVE → TOOLS → NEW takes you back there, and INIT resets just the track’s sound to its engine’s defaults (The SAVE pages). To pick an engine rather than a sound, turn KNOB 2 on the PRESETS page below.

When you’ve shaped a sound you like, keep it in one of 32 user slots. User presets show up in the PRESETS list after the factory sounds, so PRESETS finds them like any other, and they can be favourites.

The engine is the kind of synthesis a track uses. Loading a preset picks it for you; to choose one directly, turn KNOB 2 on SAVE → PRESETS (The sound bank). All twelve come from Felucca, the firmware SLOOP is built on.

Each engine has eight parameters. Tap EDIT for the first four, on EDIT 1, and tap it again for the other four, on EDIT 2. The screen titles the two pages with the engine’s own names from the table above, and the engine explorer in this guide uses them too. After the engine’s pages come FILTER (ANALOG only), then VOICE and VOICE 2, which every engine shares (Polyphony and voice modes).

ANALOG is SLOOP’s virtual analogue synth: two oscillators with detune and a dash of noise, then a resonant filter with drive. It plays 17 factory sounds, among them the moving basses (ACID 303, REESE, WOBBLE, FUNK BASS), the big leads (SUPERSAW, G-FUNK LD, PWM LEAD), pads such as WARM PAD and DARK STR, TRAP PLUCK and SYN BRASS.

ANALOG has a third page of its own, FILTER (2.6). Its TYPE turns the low-pass into a band-pass or a high-pass; CUT, RES and KTR there are the very same values as on EDIT 2, so changing one changes the other.

TRIO stacks three oscillators. INT2 and INT3 set the second and third at their own intervals from the first, so one key can sound a whole chord: that’s how MIN STAB, MIN7 STAB, RAVE STAB and DUB CHORD work. A multimode filter follows. TRIO also plays FAT BASS, SAW PAD, ENSEMBLE (a 70s string machine), SYNC LEAD, HOOVER, 80S POLY and ACCORDION, two reeds tuned slightly apart.

DIGITAL is four-operator FM, and with 22 factory sounds it’s the second busiest engine after PHYS. It covers most of the electric pianos (RHODES, DX RHODES, WURLI, M1 PIANO, AFRO KEYS), CLAV and FM GRAND, the tuned percussion (KALIMBA, MARIMBA, XYLOPHONE, GLOCKEN, CELESTA, STEEL DRUM), PLUGG BELL and TRAP BELL, GLASS PAD, FM BASS and BASS GTR.

ALG chooses one of eight ways to connect the four operators, and R2–R4 tune operators 2–4 as ratios. On EDIT 2, IDX is the amount of FM, your main brightness control, MDEC how fast the modulators decay, and FB the feedback. DIGITAL stayed exactly as it was when the six-operator FM6 arrived in 2.4.

PHASE is phase distortion in the style of Casio’s CZ synths, after CrispyZebra’s code. Rather than filtering a wave, it bends its phase: DCW sets how far, and ENV gives that amount an envelope. EDIT 2 adds detune, a sub-oscillator and LINE, which mixes or ring-modulates the two waves. Every CZ sound is PHASE (CZ BASS, CZ STRING, CZ PAD, CZ LEAD, CZ RESO, CZ BRASS), plus SOFT KEYS and RESO PLUCK.

LOFI is an 8-bit chip voice. It plays a pulse, triangle, saw, noise or a small wave table through chip modes from 1-bit to 8-bit, with the pitch sweeps, vibrato and quick arpeggios of old game consoles. Its factory sounds are GB BASS, NES BASS, GAME LEAD, WAVE LEAD, 8BIT ARP, 1BIT BEEP, CHIP CHORD and CHIP NOISE.

NOISE (2.5) sends noise through a resonant filter. MODE picks the source: ANLG for coloured noise (COLR runs from white through pink to brown), DUST for crackle, LFSR for shift-register tones and META for metallic ones. On LFSR and META, two knobs change job: DENS becomes LEN, the register, and CRSH becomes CLK, the clock above the key. Its eleven factory sounds range from pads (WIND, OCEAN) and a lead (NZ ARCADE) to effects such as RAIN, VINYL, HISS, RISER, NZ SNARE, NZ METAL, BITCRUSH and RADIO.

SAMPLE plays recorded instruments. SET picks one of eight built-in sets (PIANO, BASS, VIBES, HORNS, STRGS, FLUTE, SCRCH, PERC) or one of your own sample slots, USR1–USR4 (Your own samples). The built-in recordings are free CC0 material from Versilian Studios’ VSCO-2 CE and VCSL and from Sonic Pi, coloured as if played through an old sampler.

GRAND PNO is a Steinway recorded note by note, and its long notes fade the way a real piano’s do; DUSTY PNO and LOFI KEYS are that piano through an old sampler. SAMPLE also plays UP BASS and DEEP BASS (a real upright), VIBES, LOFI FLUTE, HORN STAB, STRING STB and GM KIT.

GRAIN is granular synthesis: it plays a sample as a stream of tiny grains. SRC can be any sample set, your USR slots included. POS chooses where in the sample the grains come from, SIZE and DENS how long and how many they are, and EDIT 2 adds pitch, spread and randomness. Its factory sounds are the slow, blurred ones (LOFI CLOUD, VIBE HAZE, STR CLOUD, SHIMMER, DRONE, PNO FREEZE, HORN CLOUD) and the lead FLUTE DUST.

VOICE is a formant synth, after klattsch. It shapes a buzzing source into vowels, which lets it sing choirs and talk like a talkbox. VOWL and VOWL2 set two vowels, TALK how long the move from one to the other takes, and SHIFT moves the formants up or down by as much as 12. Its factory sounds: CHOIR AAH, SOUL OOH, VOX PAD, TALKBOX, HARMONICA, ROBOT and WOW BASS.

WHEEL is a tonewheel organ. REG starts you from one of 16 drawbar registrations (FLUTE, MELLO, GOSPL, ROCK and others), and SUB, BODY and TOP push groups of drawbars up or down by as much as 8. EDIT 2 brings the organ’s percussion, key click, drive and a rotary speaker at SLOW or FAST. Eight of the ten organs in the bank are WHEEL: SOUL ORGAN, GOSPEL, JAZZ ORGAN, DIRTY B3, HOUSE ORGN, ROCK ORGAN, CHAPEL and REGGAE ORG.

PHYS doesn’t play a waveform: it models an object being struck, plucked or bowed. The models are those of DaisySP and Mutable Instruments’ Rings by Emilie Gillet, as Felucca 1.0 ported them. MODEL chooses the object; the BODY page shapes it and the EXCT page decides how it’s played.

With 26 factory sounds, PHYS has the most of any engine: guitars (NYLON GTR, STEEL GTR, MUTED GTR), KOTO, BANJO, SITAR, TANPURA, PHYS HARP and PLUCK BASS; bells and bars such as CHIMES, BIG BELL, VIBRA BAR, MODAL BAR, STEEL PAN and WOOD BLOCK; bowed sounds (CELLO BOW, GLASS BOWL, BOWED MTL); and hand drums (TABLA, CONGA, HAND DRUM, MEMB TOMS, TIMPANI).

FM6 is six-operator FM, the synthesis of the Yamaha DX7 and its glassy electric pianos, bells, brass and round basses. Under the hood it’s msfa, the core of the Dexed plug-in, as Felucca 1.0 ported it to the FM-1.

Six operators won’t fit on four knobs, so the eight EDIT values are macros. They sit on top of the patch and lean on all of it at once: MLVL brightens or darkens every modulator together, MEG speeds up or slows down their envelopes, and so on. For the patch itself, use the web editor (DX7 patches and the FM6 editor).

You edit full FM6 patches in the The web editor, not on the FM-1. Select a track playing FM6 and open the editor’s Sound page: the FM6 panel appears with all six operators. The same panel loads DX7 and Dexed patches, so thousands of them online can play on the FM-1.

Tracks 1–3 draw on one shared pool of eight voices. The drum track has six of its own. Each engine also has a ceiling of its own: the most voices it can play when its track is the only one sounding.

When two or three synth tracks sound at once, they split the eight voices between them. A track that needs another voice takes the one that has been sounding longest.

Each synth track has one envelope. The ENV page sets its four stages, and ENV DEST sends the same envelope to the brightness, the pitch and the engine’s shape, each by a positive or negative amount.

PIT is the 808 trick: a pitch envelope that gives each note a punchy start before it settles. FLT does the same for brightness, and SHP for the engine’s shape.

Switch ESYNC ON (2.6) and ATK, DEC and REL are measured in note lengths at the current tempo rather than in milliseconds: from 0 through 1/64T and on up to 4BAR, with triplet and dotted values along the way. They follow the tempo as it changes, so an ATK of 1/4 lasts half a second at 120 BPM and a full second at 60. OFF goes back to times in milliseconds.

Each synth track has one LFO, a slow oscillator that moves other values. Its three pages split the job: LFO sets speed and shape, LFO 2 (2.6) locks it to the tempo, and LFO DEST decides how far it moves the pitch, the brightness, the engine’s shape and the level.