SPL IRON v2 All Black – Mastering Compressor
The SPL IRON v2 All Black is a state-of-the-art variable-bias tube compressor that merges vintage analog warmth with the clarity and power of 120V technology. Designed for mastering, the IRON compressor delivers harmonic richness, dynamic control, and musical compression without sacrificing transparency. With its advanced tube circuitry, versatile rectifier settings, and unique AirBass and Tape Roll-Off filters, IRON v2 is the ultimate mastering tool.
Key Features
- 120V Technology: Unparalleled headroom and dynamic range.
- Variable-Bias Tube Compression: Modeled after legendary vintage designs.
- Wathen CryoTone™ Tubes: Matched for precision and longevity.
- Six Rectifier Modes: Choose between germanium, silicon, LED diodes, or combinations.
- Side-Chain EQ with External Insert: Shape compression with frequency-selective processing.
- Auto Bypass: Objective A/B comparison without manual switching.
- AirBass & Tape Roll-Off: Post-compression tonal shaping.
- Completely Stepped Controls: Full recallability for mastering workflows.
Iron’s Variable-Bias Tube Concept
IRON v2 employs a remote cutoff tube circuit where sharp-cutoff tubes work in parallel with bias-controlled tubes. This dual-tube design dynamically adapts to the signal, ensuring smooth and transparent compression. The result is a well-balanced sound with an organic feel.
Custom-Tuned Tubes
Each IRON v2 unit is fitted with a set of Wathen CryoTone™ 12AX7-WCM Long Plate tubes, which are hand-matched to 12AU7 tubes. These tubes undergo cryogenic treatment to enhance sonic performance and increase lifespan. This ensures a silky, clear, and balanced sound with exceptional depth and dimension.
Precision Controls
- Input Level: Adjustable in 2 dB steps over a ±12 dB range.
- Output Level: Adjustable in 2 dB steps over a ±12 dB range.
- Attack: Six-position switch from Fast to Slow.
- Release: Six-position switch from Fast to Slow.
- Threshold: 41-step detented potentiometer for precise control.
Six Rectifier Modes
The tube stage is controlled via six selectable rectifier circuits:
- Germanium – Smooth vintage compression.
- Silicon – Fast response and transparent compression.
- LED – Adds harmonic excitement and punch.
- Hybrid Modes – Combines diode types for customized response.
Advanced Side-Chain Processing
- Side-Chain EQ: Six selectable filter modes, including low-pass, high-pass, bandpass, and a custom-designed curve by SPL’s Wolfgang Neumann.
- External Side-Chain Insert: Integrate external EQs for precise frequency-dependent compression.
Tube Bias Control
IRON v2 allows three levels of tube bias:
- Low: Subtle compression, high headroom.
- Mid: Balanced compression.
- High: Stronger compression, more saturation.
Mastering-Grade Features
- Link Mode: Syncs both channels for stereo applications.
- Auto Bypass: Enables automatic A/B comparison.
- VU Meter Switch: Displays gain reduction or output level at 0 dB or +10 dB.
Post-Compression Filters
- AirBass: Enhances low and high frequencies by +1.5 dB for added depth.
- Tape Roll-Off: Emulates the soft high-frequency roll-off of analog tape.
The Power of 120V Technology
SPL’s proprietary 120V SUPRA operational amplifiers provide:
- +/-60V internal voltage: Four times higher than conventional compressors.
- Extreme Dynamic Range: 135 dB ensures ultra-clean processing.
- Ultra-Low THD: 0.002% distortion at +10 dBu.
- Unmatched Transparency: Preserves transients while controlling dynamics.
