IGS Audio Double Triode Limiter (DTL) - Tube Microphone Preamp & Limiter
The IGS Audio Double Triode Limiter (DTL) is a versatile 2-channel tube microphone preamp with an integrated musical opto-limiter, designed to deliver rich tube saturation and dynamic control. Featuring a two-stage tube amplifier (6N1P and 6N2P tubes), Carnhill input and Edcor output transformers, and a vintage-inspired photocell limiter, the DTL excels at recording vocals, drums, synthesizers, drum machines, reamping, and direct guitar/bass. With up to 60 dB of gain, -20 dB pad, Hi-Z inputs, +48V phantom, phase reverse, and smooth limiting, it adds classic tube warmth and prevents digital clipping, making it a powerful front-end for any studio setup.
Dual-Stage Tube Preamp
The audio path consists of two discrete tube amplification stages. The first stage saturation depends on input level (adjustable with pad), while the second stage is controlled by the Output knob for flexible drive and coloration. Balanced I/O via Carnhill (input) and Edcor (output) transformers provides rich harmonics and professional connectivity, with Hi-Z inputs on the front panel for direct instrument recording.
Musical Opto-Limiter
The built-in opto-limiter, based on 1960s/70s photocell designs, tames peaks and prevents ADC clipping with smooth, transparent operation. The Limit LED indicates when the limiter is active. It adds glue and control to drums, buss mixes, or individual tracks, enhancing overall dynamics while preserving musicality.
Key Features of the IGS Audio Double Triode Limiter
- Two-stage tube preamp with 6N1P and 6N2P tubes
- Carnhill input and Edcor output transformers
- Up to 60 dB gain with -20 dB pad
- Hi-Z instrument inputs on front panel
- +48V phantom power and phase reverse
- Integrated opto-limiter with vintage photocell circuit
- Output level and limiter threshold controls
- Analog VU meters for output level monitoring
- Balanced XLR I/O
- Internal linear power supply
Technical Specifications
- Type: Tube microphone preamp with opto-limiter
- Input Impedance: 300 Ω (mic), 1 MΩ (Hi-Z)
- Output Impedance: 600 Ω (balanced)
- Operating Level: +4 dBu
- Max Output Level: +22 dBu
- Max Gain: 60 dB
- Max Gain Reduction: 18 dB (limiter)
- Frequency Response: 20 Hz–20 kHz (±0.3 dB)
- THD+N: <0.1%
- Power Consumption: 40 W
- Power Supply: Internal, 115/230 V AC, 50–60 Hz
- Dimensions: 19" rackmount (2U)
- Shipping Weight: 7 kg
- Tube Set: 6N1P, 6N2P
