New · Version 3

APX-351

The tube front end of a legendary American tape recorder, rebuilt. Neural models running at their native 192 kHz, a low-CPU mode for big sessions, Bass Cut and a true VU, behind a brand-new faceplate.

VST3AUAAXmacOSWindows
single license

Free update for APX-351 owners · Full-version trial for 15 days · Online activation

APX-351 V3 plugin: brushed aluminium faceplate with a lamp-lit VU, valves and transformers above

See it in action

Walkthrough & demos

Overview & walkthrough

In action

Vintage American iron

A Class-A gain stage, transformer-coupled in and out — the holy grail front end that warmed a generation of recordings.

APX-351 captures that amplifier with neural models trained on the original hardware, so the triode saturation, the transformer weight and the way it gives as you push all come from the real unit.

Soft mode is gentle, musical warmth for vocals and acoustic sources. Hard mode pushes into driven territory — serious punch for drums and bass.

Two musicians writing with guitar and laptop in a warm home studio

Hear the difference

Before and after, on real material

Hear it in action across a variety of sources.

What's new in V3

Rebuilt from the tubes up.

Same two captures, Soft and Hard. Everything around them is new.

APX-351 V3 VU meter, lit amber

Native 192 kHz neural engine

The Ultra models were captured at 176.4/192 kHz, so V3 runs them there: 4× at 44.1/48 k, 2× at 88.2/96 k, straight through at 192 k. No false top-end, no aliasing, even pushed hard.

HQ MODE (192k)Soft · HardAlias-free
APX-351 V3 on a wooden desk in low evening sun

Low-CPU mode for big sessions

Switch HQ MODE off and the 44.1 kHz models run at your session rate: about a third of the CPU, level-matched, with the same latency, so you can put one on every track. Mode changes crossfade and never click. The engine picks its maths for your processor: NEON on Apple Silicon, AVX2 on modern Intel and AMD.

~⅓ the CPUApple Silicon NEONIntel/AMD AVX2
APX-351 V3 in a studio control room

Bass Cut

Keep the lows clean while the tubes work on everything else. A 120 Hz crossover sends only the mids and highs through the saturation; the low end rejoins at the model's own level, so the balance stays put as you drive it.

120 Hz splitLevel-matched lowsOne button
APX-351 V3 in a dark studio with amber light

A VU that tells the truth

Real VU ballistics, sample by sample: 300 ms rise, 0 VU at −14 dBFS, a needle that rests at −20 behind a lamp-lit dial. Plus AUTO gain matching, A/B, undo/redo, HPF/LPF, Mix and 50 presets in five banks.

True VUAUTO gain50 presetsA/B · Undo
Songwriters at work

In session

Warmth, first in the chain

Track vocals and acoustics through Soft; send drums and bass through Hard. Turn on Bass Cut to keep the kick and bass tight while the tubes warm the rest. With HQ MODE off it costs so little you can leave it on every channel.

Specifications

The fine print

TypeTube tape-electronics preamp — neural (LSTM) models of the original hardware
CharacterSoft · Hard
EngineNative 176.4/192 kHz (HQ MODE) or host rate (low-CPU)
FormatsVST3, AU, AAX — 64-bit
SystemsmacOS 10.13+ (Apple Silicon & Intel) · Windows 10+
ControlsDrive, Input Trim, Character, Mix, Output, Bass Cut, HQ Mode, HPF/LPF, AUTO
MeterTrue VU, 0 VU = −14 dBFS
Presets50 factory presets in 5 banks · A/B · Undo/Redo
LicenseOnline activation · free update for APX-351 owners
Trial15-day full version, no feature limits

Try before you buy

The demo is the full plugin for 15 days — decide with your ears.

Bundle value

Also in the Tube Preamp Bundle.

Instant delivery

License and installers arrive by email the moment checkout completes.

The holy grail, on every track