API Vision Channel Strip Legacy

Vision Legacy is the original UAD DSP channel-strip design, distinguished by its LEGACY badge and output knob. The linked collection manual explicitly documents it alongside the updated version, so the shared modules should not be mistaken for identical feature sets.

Legacy includes the 212L preamp, 215L sweep filters, 235L gate/expander, 225L compressor/limiter, and 550L EQ. It lacks the modern separate mic/line gain controls, independent line-pad value, dedicated 212L rumble filter, selectable 560L graphic EQ, and modeled output fader/buffer clipping. Its clean output trim and lower DSP requirements make it useful when console-style processing is wanted without those additions.

The configurable routing remains important: filters and EQ can work in the audible path or feed the dynamics sidechain, and PREDYN moves EQ ahead of dynamics. Start with preamp gain, then activate and tune each needed module rather than engaging the entire strip by default. Use the output knob to level-match comparisons. Unison support remains available through the appropriate Apollo insert, with Legacy-specific filter interactions described in the manual.

Manual — sections: API Vision Channel Strip Legacy (UAD-2 DSP only); Signal Flows; Unison Integration (UAD-2 DSP only).

• 212L Gain (Legacy): One gain control spans 30–65 dB, default 40.5, for mic and line signals. The manual describes a −32 dB internal input attenuation for line-level operation. There is no modern INPUT selector or independent Line Gain knob.
• 212L PAD / Phase / Meter: PAD is 20 dB for both input types in ordinary operation; Unison Line mode does not offer PAD. Phase flips polarity. The ladder meter reads the preamp output. Legacy has no dedicated 212L Cut Filter; its Unison low-cut action enables the 215L instead.
• 215L Filters: Hi-Pass sweeps 12–596 Hz at 12 dB/octave; Lo-Pass sweeps 643 Hz–40.8 kHz at 6 dB/octave. ON activates the module. SC removes its filters from the audio path and sends them to the dynamics detectors.
• 235L Threshold / Depth: +25 to −47 dB threshold controls which quieter signals are affected; Legacy defaults to 0 dB. Depth spans 0 to −80 dB. Choose GTE for gating or EXP for 1:2 downward expansion.
• 235L Timing: Attack offers 25 ms Normal or 100 microseconds Fast. R/H spans 50 ms–3 seconds. REL/HLD selects release or gate hold; hold is gate-only and leaves a fixed 100 ms release. ON enables the module and the meter shows attenuation.
• 225L Compression: Threshold spans +13 to −18 dB and Ratio runs continuously from 1:1 to infinity. Attack choices are 2, 18, and 75 ms; Release spans 50 ms–3 seconds with program-dependent behavior. Makeup gain is automatic. Soft/Hard Knee changes onset, OLD/NEW selects feedback/feed-forward detection, and ON enables the module. Its meter shows reduction.
• 550L Frequency / Gain: Inner knobs choose discrete frequencies; outer knobs select 0, ±2, ±4, ±6, ±9, or ±12 dB. LF covers 30–400 Hz, LMF 75 Hz–1 kHz, HMF 800 Hz–12.5 kHz, and HF 2.5–20 kHz at fixed choices. LF/HF can be peak or shelf; Q narrows as adjustment increases.
• EQ Routing: PREDYN moves EQ before dynamics. The Legacy SC button routes EQ into detection instead and overrides PREDYN. EQ ON enables the module. There is no 560L or EQ TYPE selector.
• Global: Output provides clean −24 to +12 dB trim. The output ladder reads peaks. SC Link links stereo dynamics for image stability; it is unavailable in mono. Power bypasses the entire strip.

Manual — sections: 212L Gain (Legacy); 215L High/Low Sweep Filters; 235L Gate/Expander; 225L Compressor/Limiter; 550L Four-Band Equalizer; Output Knob (Legacy).