The Holy Grail Tube Preamp
APX-351
The front end of a legendary American tape recorder — Class-A triode warmth with Soft and Hard saturation modes.
Full-version trial for 15 days · Free updates · Online activation
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 emulates a renowned vintage recording amplifier with neural-modeled triode saturation for authentic harmonic coloration.
Soft mode is gentle, musical warmth for vocals and acoustic sources. Hard mode pushes into driven territory — serious punch for drums and bass.
Hear the difference
Before and after, on real material
Hear it in action across a variety of sources.
What's inside
Soft or Hard.
Always analog.
Two saturation models
Captured from the original hardware: Soft for gentle musical warmth, Hard for driven saturation and grit. Auto-Gain keeps levels honest as you push.
Ultra-X & filters
Very high sample-rate models virtually remove aliasing at extreme settings, with Dry Mix and HPF/LPF to finish the signal path.
In session
Warmth, first in the chain
Track vocals and acoustics through Soft mode; send drums through Hard. Either way the transients smooth naturally — no compressor needed.
Specifications
The fine print
| Type | Class-A tube preamp — neural triode model |
| Modes | Soft · Hard |
| Formats | VST3, AU, AAX — 64-bit |
| macOS / Windows | Apple Silicon & Intel · Windows 10+ |
| Processing | Ultra-X very high sample-rate models |
| Controls | Drive, Output, A-Gain, Dry Mix, HP/LP |
| License | Online activation required |
| Trial | 15-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.
Complete your chain
