The American 25 Bus Compressor 50th Anniversary Edition is the American factory's dynamics flagship. Carefully designed to deliver American's signature analog sound, the A25 Ultimate delivers warmth, clarity and punch, whether used for subtle adjustments in mastering or heavy compression effects in mixing.

What’s in the library programs
- ULTIMATE proprietary technology in sampling and programming for superlative audio quality
- 4 sample rates: 44.1 - 48 - 88.2 - 96kHz
- Nebula4 JPN skin and Nebula3 Standard AlexB skin

- Feedback (Old) and Feedforward (New)
- Compressor Ratio: 1.5, 2, 3, 4, 6, 10, 12:1 (Limiter)
- Attack time: 0.03, 0.1, 0.3, 1, 3, 10, 30ms
- Release time: continuous from 50ms to 3s
- TRST with TONE control: Norm, Med, Loud
- Internal sidechain High Pass filter
- External sidechain control (Nebula4 only)
- Dry/Mix continuous control
- Line Out module with G.Drive

This program library works in licensed Nebula3 and Nebula4, NOT Nebula3 1.3.505 or N4-Player

Note for MAC users:
From Acustica Audio: "After several tests, we have detected that our products do not run correctly in the Rosetta 2 mode and we recommend using always application with a specific build for Silicon computers."
To use ULTIMATE libraries on MAC computer you need to upgrade to Nebula 4.5 (rev. April 2022) also.