Spin Sampler

Story

Open it and music is already playing: Deck A has a loop on it, ready to scratch. Put any sound on a record and move it with your hand: forward, backwards, slowed down, sped up, just like vinyl. Load a second deck, blend the two with the crossfader, throw in a brake or an echo-out, and record the whole mix. What you save is exactly what you heard.

Specifications

• Decks: 2 on Producer Starter and Pro Studio; 4 on Label Enterprise and White Label. The plan's layout is fixed and decided on the server.
• Four-deck battle view (4-deck plans): All 4 decks / A + B / C + D; hidden decks keep playing and aren't drawn (an IntersectionObserver pauses their drawing, not their sound) and are listed in the bar; phones start with A + B and switch with a sideways swipe on a deck (not its record); the choice is kept in the browser (localStorage); on 4 cores or fewer (or 4 GB or less, where the browser reports it) a note suggests two at a time.
• Plan locks (in the app; the demo has none): a control the plan doesn't include stays pressable (aria-disabled, 🔒) and opens an upgrade prompt — a native dialog saying what the plan that has it adds and "You're on <plan>", Compare plans → /music/pricing (utmsource=spin, utmcontent = moves / decks / saves; no prices in the prompt), Not now / Escape return focus — logged as spinupgradeshown. 2-deck plans show grayed Deck C and D slots below the decks (above the mixer on a computer; after Deck B on an upright phone); at the monthly save limit "more saves" (and a refused save) opens it. The server enforces the plan regardless: deck count (toomanydecks), mono on Producer Starter, the monthly limit, and no account saves of the demo rig.
• Crossfader assign (every plan): Left / Off / Right per channel (Off = the crossfader doesn't touch that channel); the crossfader's end labels and its accessible name follow the assignment; saved with a take's mixer settings.
• Never silent: Deck A opens looping — what you last played (by hand; never a file from the device) → your latest capture → the Boom Bap Welcome Loop; if nothing loads, a soft 4-second tone; /music/spin/<capture> goes first. Master at 70% (remembered). Autostart on; where the browser needs a tap first, "Tap anywhere to start the music". Leaving the page stops it; coming back resumes the same sound where it was (kept 12 hours) or from the start (setting). Pauses in the background unless set to keep playing. The first-visit hint appears once.
• TRAX Welcome Loops: 15 eight-bar loops at 120 BPM (16 s, 32 kHz mono WAV, seamless, CC0, synthesized by TRAX from the TRAX kits): Boom Bap, Lo-Fi Chill, House 4/4, Trap 808, Techno Pulse, Jazz Hop, Soul Sample, Electronic Groove, Ambient Pad, Vocal Chop, Disco Funk, Afro Bounce, Synthwave, Dembow, Breakbeat.
• Loop / mute / clear: 🔁 Loop per deck (a sound not made to loop gets a 6 ms fade at the seam); 🔈 Mute per deck and 🔈 Mute all (silent, still turning); ⏏ Clear decks (silence).
• Settings (Settings → Spin Sampler, or ⚙ on the page): open with last played / a random Welcome Loop / a chosen loop / nothing; volume; autostart; Welcome Loops on every deck (only Deck A plays); background pause or keep playing; resume where it was or fresh. Saved to the account once the C22c+ database update runs (until then, in the browser).
• Sources per deck: the TRAX Welcome Loops, your audio captures, Create tracks (voice, imported, sample), the 18 TRAX Original Sounds, the Instrument Library (rendered as a 3-second phrase), or a file from your device (decoded in the browser, never uploaded). Up to 10 minutes per sound.
• Turntable: 33⅓ rpm; the hand controls the platter directly (−8× to +8×; held still = silence); the motor brings it back to speed in about 0.4 s; varispeed (pitch and time together), backwards when pulled back; a 15 Hz rumble filter, so a stopped record sends nothing.
• Controls per deck: Start / Stop, Cue (back to the start), Brake (≈1.5 s wind-down), Backspin, Echo out (⅜ s echo, 60% feedback, 3 s); keyboard: Space, ← / →.
• Mixer: a fader per deck (squared taper), an equal-power crossfader (decks A and C on the left, B and D on the right), master volume, a level meter per deck and for the master, and a limiter (−3 dB threshold, 20:1) that holds peaks just below full scale.
• EQ and Solo (every plan and the demo): a 3-band EQ per channel — Hi (high shelf, 8 kHz), Mid (bell, 1 kHz, Q 0.7), Low (low shelf, 100 Hz) — each −24 dB to +6 dB in 0.5 dB steps (−24 shows as "off"), double-click a band or EQ flat = flat; Solo per channel (while any channel is soloed only the soloed ones are heard; the others keep turning). EQ and solo are part of the recorded master output and of the take's saved mixer settings.
• Pitch and BPM (every plan and the demo): a pitch fader per deck, ±8% in 0.1% steps (the motor's target speed; kept when the sound changes; double-click or Reset pitch = 0). BPM readout = the sound's tempo × (1 + pitch): Welcome Loops are 120 BPM (known, one decimal); any other sound is a best guess made in the browser from its first minute (onset-energy autocorrelation, 60–180 BPM, shown as "≈"; can read ⅔ or ½ of the tempo on swung / half-time beats; no steady beat → "—"); Tap (4+ taps, the last 8 after any pause over 2 s) sets it exactly until the sound changes.
• Recorder: records the master output (what you hear), up to 5 minutes; Producer Starter records mono; the recorder's Echo out echoes every turning deck and keeps the 3 s tail; a silent take is flagged; Record waits while a sound is still loading, and sounds can't be swapped mid-take.
• Saves: to Captures (a sample capture named after the decks heard in the take, e.g. "Rhodes + Piano (spin)"; up to 50 MB, about 4½ minutes in stereo) or as a WAV download; Producer Starter: 5 a month in mono; Pro Studio and up: unlimited, stereo. A failed upload resumes without costing a second save.
• Public demo (/music/try-spin and "Try it live" on the home page, no account): 2 decks, the mixer and every move; Deck A opens playing the Boom Bap Welcome Loop (the TRAX Spin Break is in the list); TRAX sounds or a file from the device (up to 10 MB and 60 s, decoded in the browser, never uploaded); records up to 60 s and plays the take back in the tab. No saving without an account (Bianca, 2026-10-02; 1.23): "🔒 Sign up to save" and "🔒 Sign up to download" open the signup with Pro Studio picked (Request access while trials are closed); the take is never kept, uploaded or downloadable, and is gone when the tab closes; after signing up, Spin Sampler starts fresh with the same Welcome Loops. Shares send the demo's link with a caption (X; TikTok / Instagram copy the caption + link; copy link with campaign tags; the phone's share sheet), never the recording. (Mixes kept in a browser before 1.23 are still offered at the next sign-in there — "Add to my Captures" or "Not mine — delete it" — until they clear after 30 days.) Analytics: demosaveto_trax with want=save|download = a conversion attempt; anonymous counts only for visitors who aren't signed in (Vercel Web Analytics events, no cookies).
• What's stored with a save: the audio (Captures only), what was on each deck (a file's name only), the mixer's settings, the plan's rig and the length. No audio is stored while you play.

How to

1. Open Spin Sampler (or try it without an account at /music/try-spin). A loop is already playing on Deck A.
2. Drag Deck A's record to scratch it. Choose another sound on Deck B.
3. Press ▶ Start on Deck B.
4. Use the faders and the crossfader to blend the decks.
5. Press ● Record, perform, then ■ Stop recording.
6. → Save to Captures or ⤓ WAV.

Shortcuts

• Click a record, then Space to start or stop it, hold ← to pull it back, → to push it forward.
• Double-click the crossfader to center it.

What you can do

• Scratch, brake, backspin and echo out any sound you own, or one of the TRAX Original Sounds.
• Mix 2 decks (4 on Label Enterprise and White Label) with faders, a crossfader, a 3-band EQ and Solo per deck.
• Match tempos by ear and by number: a ±8% pitch fader and a BPM readout per deck, with Tap tempo.
• Battle with four decks: show all four or two at a time (the others keep playing), and put any deck on either side of the crossfader, or off it.
• Record a full performance and use it as a capture in a Create sketch or a project.
• Let anyone try it from the home page, and keep a demo mix by signing up.

What you can't do (yet)

• Generate your own Welcome Loop with AI (Coming soon).
• Build your own rig (add or remove decks, samplers and effects): Modular Spin is planned after launch.
• Change a deck's sound while recording; stop the take, swap it, and record again.
• Automatic beat matching (sync) or loop points.
• Chladni patterns in Spin (coming with the shared TRAX Chladni visuals).

Plans

• Producer Starter: 2 decks with the mixer and crossfader; 5 saves a month, mono; brake, backspin and echo-out are locked.
• Pro Studio: 2 decks; unlimited stereo saves; brake, backspin and echo-out.
• Label Enterprise: 4 decks (A to D) and a 4-channel mixer; everything in Pro Studio.
• White Label (by waitlist): 4 decks, as Label Enterprise.

Related

• Help: Spin Sampler — scratch and mix any sound.
• Captures, Create, Instrument Library.

Changelog

• 1.23 · 2026-10-02: The public demo plays and records as before, but saving needs an account: "Sign up to save" / "Sign up to download" lead to the signup; the take stays in the tab; shares send the demo's link.
• 1.22 · 2026-10-02: Plan locks explain themselves: a 🔒 control (Brake, Backspin, Echo out on Producer Starter; Echo out while recording) and grayed Deck C and D slots on 2-deck plans open a prompt with what the next plan adds and Compare plans; "more saves" at the monthly limit.
• 1.21 · 2026-10-02: Four-deck battle view (All 4 / A + B / C + D, hidden decks keep playing, swipe between pairs on a phone, a note on modest devices) and crossfader assign (Left / Off / Right) on every channel.
• 1.20 · 2026-10-02: Pitch fader (±8%) and BPM readout per deck (Welcome Loops 120; other sounds estimated, "≈"; Tap tempo); 3-band EQ (Hi / Mid / Low, −24 to +6 dB) and Solo per channel. Every plan and the demo.
• 1.19 · 2026-10-02: Never silent: Deck A opens with a sound looping (last played → latest capture → a Welcome Loop), 15 TRAX Welcome Loops, Loop / Mute / Mute all / Clear decks, Settings → Spin Sampler, "Tap anywhere to start the music", coming back where you were.
• 1.18 · 2026-10-02: The public demo: try Spin Sampler without an account at /music/try-spin and on the home page — two decks, every move, a 1-minute recorder, Download WAV, share, and Save to TRAX (at the next sign-in on that browser, add it to your Captures).
• 1.17 · 2026-10-02: Two decks and a mixer (four on Label Enterprise and White Label): channel faders, an equal-power crossfader, master volume and level meters; the recorder now keeps the master output, so a take has every deck and every move in it; echo-out on every deck; silent takes are flagged.
• 1.10 · 2026-10-01: Spin Sampler: one turntable, scratch any sound, brake, backspin and echo-out, record and save the performance.