AlphaRail
Alpha before the feedback.
An op-amp preamp inspired by the ARP 2600 (1971), now with two engines. Bandwidth crashes, slew gives up — gloriously.
- VST3 + AU + CLAP
- macOS (Universal) + Windows 10+ (VST3 + CLAP)
- Instant download via Gumroad
- macOS builds notarized by Apple
- No account. No iLok. No subscription.
Audio demos are being recorded — dry against wet, same take, no cherry-picking.
Two engines
The CIRCUIT button picks one. Circuit, the default, is built from the preamp’s service-manual schematic and the datasheet of its op-amp, noise included. Classic is the AlphaRail of v0.4: the stage pushed past its 1971 specification.
Three RANGE positions
×10, ×100, ×1000: 20, 40 and 60 dB. They’re voicings, not volume. In Classic, one hits a bandwidth wall at 1 kHz. We kept it.
Three failure modes, at once
Push a 1971 op-amp past spec and two things happen together: the gain-bandwidth product collapses and the slew rate runs out. Classic adds a third on purpose: one side of the wave clips before the other. That lopsided clip is where the second harmonic comes from — a choice made for the sound, not a measurement of the chip.
Not warm, not tube
This is not transistor saturation with a sweater on. It is what an op-amp sounds like when you ask it to do impossible things. At ×1000 Classic stops being a preamp and becomes a lo-fi shaper with opinions.
Level-matched from the start
New instances open in the Circuit with AUTOGAIN on: on pink noise at −18 dBFS the default settings come out within 0.1 dB of the dry signal. You hear the color, not the volume.
Not a demo — the whole plugin
Free, and it stays free. Nothing is locked, nothing expires. Updates arrive through the same Gumroad link.
A second engine, built from the original preamp’s schematic, and new defaults.
- Circuit
- A new engine with its own button. GAIN is the input pot ahead of the op-amp, on a log taper; RANGE switches the gain network. A soft limiter before the stage and a soft saturator after it are the plug-in’s own design, not a measurement of the chip.
- Classic
- The AlphaRail of v0.4, unchanged. The engine is saved with the project, with presets and with the A/B snapshots; latency is the same as in v0.4.
- Noise
- The Circuit has its own noise: with AUTOGAIN off, about −113 dBFS A-weighted at ×10, −93 at ×100 and −73 at ×1000. Classic has none.
- Defaults
- New instances open in the Circuit with AUTOGAIN on and OUTPUT at 0 dB. The factory presets load the Circuit, each within 0.1 dB of the dry level. Hovering over GAIN or OUTPUT shows its value.
- CPU
- About 3.9 % of one core at 48 kHz at the default settings, against about 1.2 % for Classic. Driven hard, the Circuit costs more: up to about 11 % in the worst case we measured.
- Fixed
- A NaN or infinite sample from earlier in the chain no longer leaves a channel invalid until the plugin is reloaded. Save preset opens inside the plugin window. Safe with oversized buffers from offline bounce and track freeze. A workaround for the dead corner in Logic, GarageBand and MainStage on macOS Tahoe.
Already have AlphaRail? Same Gumroad link: download it again. Projects and presets saved with 0.4.x open in Classic with the same settings. To try the Circuit on an old project, turn AUTOGAIN on before pressing CIRCUIT.
AlphaRail is inspired by the ARP 2600 (1971), the semi-modular behind R2-D2’s voice: Ben Burtt made it by pushing his own voice through the synth’s resonant filter, with a tape-recorder microphone inside the machine. Its documented users are a scene rather than a single record — Stevie Wonder, Pete Townshend, Edgar Winter, Jean-Michel Jarre, Weather Report, Depeche Mode, Joy Division, Nine Inch Nails.
AlphaRail models one specific stage of that machine — the input preamp op-amp pushed past its specification. Not the filter, not the oscillators, not the spring reverb. The op-amp character, isolated and made playable on any source.
Closed-loop preamps like this were never meant to be musical. They were utility amplifiers, built to route external signals into the synth voice. Pushing them was the mistake that turned out to be the sound.
ARP and ARP 2600 are trademarks of Korg Inc. Pointless Audio is not affiliated with, endorsed by, or sponsored by Korg. Product names are used solely to describe the hardware that inspired this plug-in.
- Formats
- VST3 + AU + CLAP
- Platforms
- macOS (Universal) + Windows 10+ (VST3 + CLAP)
- Version
- v0.5.0
- License
- Perpetual — no account, no iLok, no subscription
- Manual
- Online manual · PDF
- Price
- Free
Or get all six in one download — The Pointless Collection, free until 25 October.
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01
Get it on Gumroad
Checkout runs on Gumroad. It’s free: enter 0 in the price field. The download link lands in your inbox.
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02
Download the zip
Inside: VST3 + AU + CLAP builds and the manual as PDF. macOS builds are notarized — no Gatekeeper drama.
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03
Install, rescan, done
macOS: run the signed installer in the zip and pick your formats. Windows: copy the plugin into your plugin folder. Rescan in your DAW. No account, no activation. The manual has the exact paths.
How do I install it?
On macOS, run the installer inside the zip: it is signed and notarized, and lets you pick the formats. On Windows, copy each format into your plugin folder. Then rescan in your DAW. The manual walks through the exact paths.
Do I need an account, a dongle, or an internet connection?
No account, no iLok, no subscription, no activation. Once installed it runs fully offline, forever.
Does it work in my DAW?
Any host that loads VST3 + AU + CLAP: Logic Pro, Ableton Live, Reaper, Bitwig, Cubase, Studio One, FL Studio and friends. No AAX — Pro Tools is not supported.
Windows says the file is from an unknown publisher.
Windows builds are not code-signed yet, so SmartScreen may warn on first run. The zip you download from Gumroad is the zip we built — choose “Run anyway” or unblock the file in Properties.
Refunds?
Payments run through Gumroad, refunds follow Gumroad’s policy. If something is broken, write to [email protected] first — most problems are a five-minute fix.
Are updates free?
Yes — free updates within the current major version, delivered through the same Gumroad link.