SILTH

01Welcome

Most lo-fi effects make a sound worse. SILTH makes it older. It gives you the parts of old gear that people love: the warmth of tape, the grit of an early sampler, the dust and wobble of a well-played record. The clarity of your sound stays underneath.

One big knob, AGE, runs it all. Turn it down and the sound is clean. Turn it up and the tape, the converter and the vinyl all wear in together. Underneath sits a live granular engine that can smear, stretch, freeze and scatter whatever comes in.

AGE sets how much of the TAPE, DECIMATE and VINYL sections you hear. GRAIN is a creative engine of its own and isn't moved by AGE. Around all of this sit a bubble-TV screen, a CAPTURE recorder, a SAMPLE page for printing files through SILTH, eleven modulation sources and a MIDI MAP.

02Installing

SILTH runs on macOS and Windows as a plugin in your DAW and as a standalone app.

Run the installer, then open your DAW. If SILTH doesn't appear in your effects list, ask your DAW to rescan its plugins. SILTH is an audio effect: load it as an insert on an audio track, a bus or group, or the master. It works in mono or stereo.

SILTH also listens for MIDI, so a keyboard or controller can play its modulation and MIDI MAP. To use that, send MIDI to the track SILTH sits on. Some DAWs don't pass MIDI to audio effects.

In the standalone app, SILTH processes the input of your audio interface. The AUDIO / MIDI button in the help bar picks your audio device and MIDI keyboard.

The first time a newly installed plugin opens, your computer may check it before it loads. Let that finish. The next time it opens straight away.

03Activating your licence / free trial

SILTH comes with a 14-day free trial. Everything works, and there is nothing to sign up for. The first time you open SILTH, a short welcome card explains how the trial works.

To unlock SILTH for good, buy it at sequoiasynths.com. Your licence key appears on the thank-you page and comes by email, with a .seqlicence file.

1. Open SILTH and click the trial status at the bottom of the window, or right-click HELP and choose Licence...
2. Paste your key (it starts with SEQ-), or drop the .seqlicence file onto the panel.
3. That's it: SILTH is unlocked on this computer, in every project, and every open SILTH window unlocks at once.

SILTH checks your key on your computer. It needs no internet connection and no account, and it never sends anything anywhere. Your licences are kept in ~/Library/Application Support/Sequoia Synthesizers/Licences on a Mac and %APPDATA%\Sequoia Synthesizers\Licences on Windows. Keep your .seqlicence file somewhere safe: it activates SILTH on your other computers too.

04Quick start

Five steps from loading SILTH to a worn-in loop in your song. For a printable two-minute overview of everything, download the SILTH Quick Guide (PDF).

1. Load SILTH on an audio track and press play. A fresh SILTH (and INIT) is clean. AGE sits at 50 % and every effect knob starts at zero, so whatever you turn up is exactly what you hear.
2. Give it some character. Turn up DRIVE and BUMP in TAPE, BITS in DECIMATE, or DUST in VINYL. Every knob works the same way: turn it right for more.
3. Or pick a whole machine. Click MACHINE in the DECIMATE title and choose a classic, such as the 12-bit drum sampler or a Cassette 4-track. Or browse the presets in the header.
4. Turn AGE. Left makes everything cleaner, right wears it further. Pull MIX down to blend in the dry sound.
5. Keep it. In CAPTURE, press GRAB LAST to keep the bar that just played, then drag WAV onto a track.

05The window

Header

The MAIN page

The MAIN page has three rows:

• Top: AGE, the screen and CAPTURE.
• Middle: TAPE, DECIMATE and VINYL.
• Bottom: GRAIN, across the full width, with the MIDI MAP button in its bottom-right corner.

The modulation chips run along the bottom, and the help bar sits below them. The version number is on the right of the help bar.

A / B, undo, size and the preset menu

A / B (in the header, right of SAVE). Two complete sounds to compare. The lit letter is the one you hear: click the other letter to switch. The first time you click B it starts as a copy of A. The arrow between them copies the lit sound into the other one; right-click it for "Copy A to B" or "Copy B to A". Both are saved with your project, never in presets, and switching never clicks.

UNDO / REDO (the raised curved-arrow buttons left of the preset name; a button is dim when there is nothing to undo or redo, and sinks in when you press it). ⌘Z undoes and ⇧⌘Z redoes (Ctrl+Z, Ctrl+Shift+Z or Ctrl+Y on Windows); Undo and Redo also sit at the top of every right-click menu. A whole knob turn is one step, and so are a preset load, INIT, an A / B switch or copy, a RANDOMIZE roll and a MIDI MAP change. Up to 100 steps; the help bar names each one. Automation from your DAW is never undone.

SIZE (bottom right, beside the version). SMALL, MEDIUM, LARGE or EXTRA LARGE, or FIT TO SCREEN. You can also drag the bottom-right corner. The whole window scales as one picture, so nothing moves around. Your project remembers its size, and new windows open at the size you used last.

The preset menu: click the preset name. A dropdown opens under it: one sub-menu per category, then MY PRESETS (the ones you saved), then Init: a fresh start, Load a preset file… and Show my presets folder. Pick one and it loads at once (one undo step). ‹ and › beside the name step through every preset.

SAVE in the header opens SAVE PRESET: type a name and click the tags that fit. The first tag is the category it is listed under.

The LED meter

The meter at the far right of the header shows the loudness of SILTH's output, left channel on the top row and right channel on the bottom row. Each row has eleven square, domed LEDs, labelled from -24 on the left up to +6 on the right, in 3 dB steps (-24, -21, -18, -15, -12, -9, -6, -3, 0, +3, +6). Green LEDs are comfortable levels, yellow ones (-3 and 0) are getting hot, and red ones (+3 and +6) mean the signal is too loud. When the level goes into the red, CLIP also lights above the meter. The meter shows the level after MASTER, so it tells you what is leaving SILTH.

The gear (settings and manual)

The Sequoia gear at the top-left corner of the window opens a menu:

• Open the manual opens this manual in your web browser.
• Window size and Fit window to screen work like SIZE in the help bar.
• Welcome screen shows the welcome window again.
• Licence / activate opens the licence panel.
• Show my presets folder opens the folder where your own presets are kept.
• sequoiasynths.com opens our website, and About SILTH shows the version in the help bar.

The welcome window

The first time you open SILTH on a computer, a welcome window appears with the name, a short hello, the version and buttons to GET STARTED or OPEN MANUAL. After GET STARTED, SILTH takes you on to activation if it is not unlocked yet. It only appears once on each computer. You can bring it back at any time with Welcome screen in the gear menu.

Section ON switches

TAPE, DECIMATE, VINYL and GRAIN each have an ON switch next to the section name. Switch one off to take the whole section out. Its knobs fade back but keep their settings, and you can still adjust them. Switching is smooth, so it never clicks.

Working with controls

• Drag a knob up or down to turn it. Hold Shift for fine moves. The mouse wheel works too. A knob shows only its name; while you point at it or turn it, its value takes the name's place.
• Double-click a knob to reset it to its default.
• Right-click a knob to step it back (up to 10 times). Each knob remembers its own last 10 settings; loading a preset starts them afresh.
• Shift + right-click (Ctrl + right-click on Windows) any knob for Undo/Redo, Modulate with ›, its modulation routings, Map to MIDI ›, Remove MIDI mapping, Reset to default and Open MIDI MAP…
• Resize the window with SIZE (bottom right) or by dragging its bottom-right corner. It stays sharp at any size.

06AGE

The big knob on the left. It turns the TAPE, DECIMATE and VINYL sections up together.

• 0 % is clean.
• 50 % puts each section exactly where its knobs are set. This is where SILTH starts.
• Above 50 % goes further than the knobs: lower rates, fewer bits, darker tone and more wobble than you set.

AGE only scales what the knobs already do. With every effect knob at zero, AGE has nothing to work with. It doesn't move GRAIN.

The three sliders under AGE all start at 100 %. Pull one down to keep that section cleaner while AGE drives the others.

Punch

PUNCH keeps kicks, snares and plucks sharp. When a hit starts, SILTH brings back the hit's level and lays part of the clean attack over the first few milliseconds. The body and the tail stay fully processed. At 0 % the effects can eat the attack.

The heaviest settings are still allowed to mangle the attack: FREEZE, very low BITS or RATE, GRAIN past 60 %, AGE far past the knobs, and DRIVE flat out.

07The screen

The middle of the top row is an old black-and-white bubble TV. Everything on it follows the sound.

The screen moves with you to the SAMPLE page, so you can watch a file being printed.

08Capture

CAPTURE records what SILTH plays so you can drag it into your DAW. SILTH is always listening, so you can even keep something that has already happened.

The waveform shows the last capture and its name. Captures are saved as 24-bit WAV files named after their length and tempo, for example SILTH 1 BAR 120 BPM.wav. See Presets and files for the folder.

09Tape

The warmth and movement of a tape machine. TAPE comes first in SILTH, before the converter and the record.

The AGE Tape slider sets how much AGE moves this section. Higher AGE and DRIVE also soften the top end a little, the way tape does.

10Decimate

An old digital converter. RATE and BITS read OFF all the way to the left, so a fresh SILTH is clean. Turn them right for more.

BITS has real bite: SILTH follows the level of the sound, so every setting grits loud and quiet parts alike, and quiet tails get grittier still.

MACHINE

MACHINE, in the DECIMATE title, turns SILTH into a whole piece of old gear in one click. Each machine sets the converter (RATE, BITS, SMOOTH, U-LAW, JITTER) and the gear around it: tape DRIVE, BUMP, FLUTTER and HISS, plus WOW, TONE, MONO and DUST. It also brings AGE up to at least 50 % and the three AGE sliders to 100 %, so you hear the machine as it was designed. Then tweak from there. One undo takes it all back.

11Vinyl

The sound of a record. All vinyl noise follows the sound, so silence stays silent.

The VINYL ON switch takes WOW out along with the rest of the section.

12Grain

This is TENFOLD's granular engine, running live on the incoming sound. It keeps the last few seconds of sound and plays tiny pieces of it, called grains, back over each other. GRAIN has its own ON switch and isn't moved by AGE.

The cloud (first row)

Deeper controls (second row)

Switches and menus

• Freeze holds the current moment, so the grains keep playing it.
• Shape sets the fade of each grain: Smooth and Soft blend, Hard is choppy, Pluck and Swell add movement.
• Scale snaps grain pitch, detune and octave jumps to a scale, relative to the incoming sound: Free, Chromatic, Major, Minor, Dorian, Pentatonic, Minor Pent, Fifths or Octaves.
• Sync, when lit, starts grains on your song's tempo grid, at the division next to it: 1/4, 1/8, 1/8T, 1/16, 1/16T, 1/32 or 1/64.
• Pitch HOLD · BEND, on the right. HOLD keeps the pitch steady while you warp. BEND lets the pitch follow WARP, like tape.

13The SAMPLE page

Run any file through SILTH and print the result as a new WAV, without recording in your DAW.

The quickest way

Drag a loop or sample from your DAW or your files and drop it anywhere on SILTH. It opens the SAMPLE page, plays the sound through SILTH once and prints it. Then drag WAV onto a track. The print is exactly as long as the loop you dropped in.

Step by step

1. LOAD… opens the file browser. The up and down arrows play each file as you move, and Enter loads one. SILTH shows the sample's name, length and the file's sample rate.
2. PLAY runs the sample through SILTH in place of the incoming sound. Everything on the MAIN page shapes it. Press STOP to end early.
3. Drag WAV out. When the pass ends, the result is printed under OUT. Drag WAV into your DAW, or press SHOW FILE to open its folder.

SILTH reads WAV, AIFF, FLAC, MP3 and OGG files, up to 90 seconds long. Prints are 24-bit WAV files named after the sample, for example Break SILTH.wav, or Break SILTH loop.wav with LOOP on.

The file browser

The browser opens over SILTH and plays each sound as you land on it, through SILTH, so you hear it already worn in.

• ↑ ↓ move through the files. → or Enter opens a folder; ← or Backspace goes up.
• Enter or a double-click loads a file. Space plays the selection again. Esc or CANCEL closes without loading. AUTO-PLAY turns the instant playback on or off.
• LOOK IN… jumps to your sample library, Downloads, Desktop, Documents, your Music folder, Home or a drive, or opens the system Open window.
• Open your sample folder and choose Add this folder to your library from LOOK IN… once. From then on, the browser opens there.

The sample you loaded is remembered with your project by its location. If you move or rename the file, load it again.

14Modulation

CHIPS are Sequoia's exclusive drag-and-drop modulation. Drag any chip onto any parameter and it moves that parameter. No menus, no matrix to set up first.

Every modulation source lives in the chip row along the bottom of the window. There are eleven chips. Each one shows a live drawing of its source moving.

VELO, WHEEL, PRESS and KEY need MIDI sent to SILTH's track (see Installing).

Routing

1. Drag a chip onto any knob. Let go and the routing is made.
2. Set the range. A coloured arc appears around the knob in the source's colour, with a dot at each end. Drag a dot to set how far the modulation reaches on that side.
3. Change or remove it. Shift + right-click the knob. Each routing has its own line with Open (for an ENV or LFO), Invert and Remove; LFO, RANDOM and KEY also have Mirror the two ends. Modulate with › adds a source from the menu; pick a ticked source again to remove it.

ENV, VELO, WHEEL and PRESS push a knob one way. LFO, RANDOM and KEY swing it both ways around where you set it. Up to 32 routings can run at once, and up to three on any one knob, chips and MIDI MAP together. Their arcs sit one outside the next, in the order you added them; if there isn't room round a knob, its dial is drawn a little smaller while it has them. A fourth chip is refused, and the help bar says so: right-click the knob to remove one first. Routings are saved with presets and with your song.

Sliders take chips too. Drop a chip on the A H D S R sliders in the ENV window and a thin lane appears beside the slider in the source's colour, with a dot at each end: drag either dot to set how far it reaches that way, just like a knob's arc. While the source moves it, the slider's cap rides the live value and a small tick marks where you set it. Up to three per slider; an ENV can't move its own window's sliders.

The two dots on an arc

• Each dot moves on its own. Drag it further out for more, or back in for less. The knob and the other dot stay exactly where they are.
• Two-way sources (LFO, RANDOM, KEY) can reach different amounts each way. The top dot is where the knob goes when the source is up; the bottom dot is where it goes when the source is down. So an LFO can sweep far up and only a little down.
• Two-way: pull a dot past the knob and the knob follows it. That is the only time a dot moves the knob, and the other dot still stays put. When both dots sit together on the knob, the first move picks: drag up for the top dot, down for the bottom one.
• One-way sources (ENV, VELO, WHEEL, PRESS) have one dot on the knob and one at the far end. Drag the far end either way; below the knob it pushes the knob down instead of up. The far dot never moves the knob. The dot on the knob does nothing when pulled toward the far dot; pulled out the other way, past the knob, it carries the knob with it.
• Even them up again: Shift + right-click the knob and choose the source's Mirror the two ends.
• Even arcs. A two-way chip (LFO, RANDOM, KEY and bend where the plugin has them) swings both up and down, so when you drop one on a knob it gets the same room on both sides: the two end dots sit the same distance from the knob, even when the knob is not in the middle. If the knob is close to an end (within 10%), it can only move one way, so the arc keeps its full depth. One-way chips (ENV, macros, VELO, WHEEL and so on) are unchanged. Dropping the same chip on the same knob again evens it the same way. Projects and presets you saved earlier keep their arcs exactly as they were. To even out an arc later, Shift + right-click the knob and choose Mirror the two ends next to that chip: both ends become the average of the two, shrunk to fit around the knob, never below 10%.
• While a dot is held, the knob's label shows that end's amount in the source's colour (DOWN for the bottom end).
• Songs and presets made before this keep both ends even, so they sound exactly the same.

While a source moves, the knob moves with it: the pointer follows, a dot rides each arc at that source's own speed, and a small tick shows where you set the knob.

Click a chip to see what it moves: every knob it's routed to lights up. Click it again to stop showing them.

Envelopes (ENV 1–3)

Click an ENV chip to open its card. Each envelope is AHDSR: attack, hold, decay, sustain and release. Drag the dots on the display or use the five A H D S R faders.

• Attack 0–10 s, Hold 0–5 s, Decay up to 10 s, Sustain 0–100 %, Release up to 10 s.
• TRIG: what starts the envelope. NOTE is a MIDI note, and letting go releases it. 1 BEAT, 1 BAR, 2 BARS or 4 BARS follow your song while it plays. INPUT fires on every hit in the incoming sound.
• VELO: how much a harder note, or a louder INPUT hit, makes the envelope go further.

Out of the box, ENV 1 is set to INPUT, ENV 2 to 1 BEAT and ENV 3 to 1 BAR.

LFOs (LFO 1–3)

• SHAPE: Sine, Tri, Saw Up, Saw Dn, Square, S&H or Random.
• SYNC: lit (the default) locks the LFO to your song, and RATE becomes a note length: 1/16, 1/8, 1/4, 1/2, 1, 2, 4 or 8 bars, or 1/16T, 1/8T or 1/4T. Off, RATE runs free from 0.02 to 20 Hz.
• MORPH bends the wave. Choose how with the morph type (Bend, Skew, Mirror, Sync, Fold, Steps, Spike, Ripple or Mutate) and set how far with the MORPH knob. RANDOM rolls a new morph type and variation.
• SMOOTH rounds off the corners of the wave. On S&H it rounds both corners of every step evenly: hard steps at 0 %, a gentle wave through every value at 100 %.
• RETRIG starts the wave again on every bar line. RISE then fades it in, up to 10 s.

The card draws two cycles of the real wave as you shape it. The tabs on the left of a card switch between ENV 1–3 or LFO 1–3, and you can drag a source straight from the card onto a knob. Esc, the × or a click outside closes it.

15MIDI MAP

Let your mod wheel, aftertouch, pedals or controller knobs move any knob in SILTH. Mappings are saved with your song (not with presets), and they work with the window closed.

1. Click MIDI MAP in the bottom-right corner of GRAIN. The MIDI MAP sheet opens above it.
2. Pick a SOURCE. It starts on Mod Wheel (CC 1). The list also has Aftertouch, Breath (CC 2), Foot (CC 4), Expression (CC 11), Sustain (CC 64), Resonance (CC 71), Brightness (CC 74) and General 1–4 (CC 16–19). Or choose LEARN… and move any knob on your controller. The NOW meter shows what the source is sending.
3. Press + ADD and pick a control. The popular ones come first (AGE, MIX, GRAIN, WARP, SIZE, PITCH, TONE, DUST, WOW and RATE), and All destinations lists the rest. Or choose CUSTOM… and simply touch the knob you want. Repeat to make one source move several controls at once.
4. Set the DEPTH: how far the controller moves the control from where you set the knob. Drag left of the middle to make it move the other way. Double-click for +50 %; the × removes it.

Mapped knobs show a pink arc and a small tag beside their label: MW for mod wheel, AT for aftertouch, CC74 and so on. A + means more than one source drives it. You can also drag the dots on the pink arc to set the depth.

The shortcut is to Shift + right-click a knob and choose Map to MIDI ›, then a source or Learn from controller… To remove a mapping, Shift + right-click the knob and choose Remove MIDI mapping.

16Randomize and undo

RANDOMIZE

RANDOMIZE rolls a whole new SILTH sound. ‹ steps back, all the way to the sound you started from, and › steps forward again. The last 20 rolls are kept.

• Right-click RANDOMIZE to choose how far it goes: MILD (nudge the current sound), MEDIUM (a new, musical sound) or WILD (everything, plus one to three new modulation routings).
• In the same menu, Lock from RANDOMIZE › keeps a part of SILTH as it is: AGE, TAPE, DECIMATE, VINYL, GRAIN, MOD (the LFO cards) or MOD ROUTINGS. Unlock all modules frees them again.
• RANDOMIZE never touches MASTER, FREEZE, PUNCH, the section ON switches or your MIDI MAP. It keeps MIX at 20 % or more, so you never end up with silence, and it holds grain FEEDBACK and RESO below their wildest settings.
• On MEDIUM and WILD it sometimes moves the grain PITCH to a musical interval, such as an octave or a fifth.

Undo and redo

Every change can be undone, up to 100 steps back, including RANDOMIZE, MACHINE, presets, A / B, modulation and MIDI MAP changes. A whole knob turn is one step. Use the curved arrows in the header or the keys below; Undo and Redo also sit at the top of every right-click menu. The undo history lasts for the session; it isn't saved with your song.

Help tips

The help bar at the bottom always explains whatever the mouse is over. With HELP on, a tip also pops up beside the control.

• Close a tip with its × once you know that control. It stays hidden, even next time you open SILTH.
• Right-click a control to bring its tip back, or right-click HELP to bring all the tips back.

17Presets and files

Factory presets

SILTH ships with 60 presets in six groups. In the preset menu each one is listed under its group:

Click the preset name for the preset menu (see above). Init: a fresh start, near the bottom of the menu, gives a clean start: every control to its default and every modulation routing removed. Show my presets folder opens your preset folder on your computer.

The factory presets are built into SILTH. Older versions copied them into your preset folder, under Factory; the ones you never changed now move to _old factory presets in the same folder, so each sound is listed once. Any factory preset you changed and saved stays where it was, as one of your own.

Your own presets

Press SAVE to store the current sound as a .silth file, with the tags you pick. It appears in the browser alongside the factory sounds. FILE… in the browser opens a preset from anywhere. Presets keep your modulation routings, but not your MIDI MAP. Copy the preset folder to move your sounds to another computer.

Where SILTH keeps its files

Saved with your song

Your DAW project keeps everything: every control, the modulation routings, the MIDI MAP, A and B, the window size, the loaded sample, LOOP and TAIL, and CAPTURE's length and tempo settings. Projects and presets made with an earlier version of SILTH load with the settings they were made with, so they sound the same.

18Sound recipes

Starting points for the sounds SILTH does best. Begin from Init each time.

19Troubleshooting

SILTH doesn't appear in my DAW

Check that the plugin is in the folder listed under Installing, then rescan plugins in your DAW. Make sure you're looking in the effects list, not the instrument list.

I don't hear any difference

A fresh SILTH is clean on purpose: every effect knob starts at zero. Turn up a knob in TAPE, DECIMATE, VINYL or GRAIN. Also check that AGE isn't at 0 %, that MIX isn't at 0 %, and that the section's ON switch is lit.

The crackle and hiss stop when the music stops

That's by design. Hiss, dust, pops and rumble follow the sound, so silence stays silent.

The grains or FREEZE stopped

Grains, FREEZE and grain FEEDBACK stop when the incoming sound goes silent for a moment, and when your DAW stops. Play some sound and they come back.

My drums lost their snap

Turn up PUNCH. The heaviest settings (FREEZE, very low BITS or RATE, GRAIN past 60 %, AGE far past the knobs, DRIVE flat out) are still allowed to eat the attack.

The CLIP light comes on

Turn MASTER down a little, or lower BUMP or DRIVE.

VELO, WHEEL, PRESS, KEY or the MIDI MAP do nothing

SILTH needs MIDI sent to its track. Some DAWs don't pass MIDI to audio effects; check your DAW's routing for effect plugins.

A sample is missing when I reopen my song

SILTH remembers the sample by its location. If the file was moved, renamed or is on a drive that isn't connected, load it again from its new place.

20Credits

SILTH's GRAIN section uses the granular engine from TENFOLD, also by Sequoia Synthesizers Co.

Interface type: Space Grotesk and IBM Plex Mono (SIL Open Font License).

Licence check: Ed25519 by Monocypher, © Loup Vaillant and contributors, BSD-2-Clause.