HLabs Audio Pre169S is a two-channel microphone preamplifier in a 1U chassis — a pair of PRE169 circuits with Neutrik NTM-4 input transformers and Carnhill VT24499 output transformers. The input stage reproduces the Studer 169 console design.
A matched pair instead of two arbitrary channels
Stereo recording — an overhead pair, XY microphones on acoustic guitar, a Blumlein array — needs two paths with the same gain and the same behaviour. Two 500-series modules from different production runs do not guarantee that. The Pre169S holds a pair of channels built together, with independent phantom power and separate earth lift on each output, so the stereo image does not drift to one side.
Output attenuation as tone control, not just level control
The combination of input gain and output attenuation (0 to -30 dB) sets how hard the large Carnhill transformer is driven. At low gain the path is close to neutral; with the input wound up and the output pulled back, density and soft transient limiting appear — the behaviour associated with classic Neve designs. That change is one knob away, with no separate processor patched in.
KEY FEATURES
- Two microphone preamplifier channels in a 1U chassis
- Input stage reproducing the Studer 169 design
- Up to 67 dB of gain, -125 dBu EIN
- Neutrik NTM-4 input transformers, Carnhill VT24499 output transformers
- Output attenuator, 0 to -30 dB, for controlling transformer saturation
- Discrete 12 dB/oct high-pass filter, tunable 20–315 Hz
- Front-panel DI input
- Independent +48 V phantom power per channel
- Polarity switch and -33 dB pad
- Independent earth lift on each XLR output
TECHNICAL SPECIFICATIONS
- Channels: 2
- Maximum gain: 67 dB, pad -33 dB, output level 0 to -30 dB
- EIN: -125 dBu at maximum gain (mic input)
- Mic input impedance: 1.2 kΩ; DI input impedance: above 1.0 MΩ
- Output impedance: below 20 Ω, transformer balanced
- Frequency response (1 kΩ load): ±1 dB from 6.2 Hz to 25 kHz
- Maximum input level: +9 dBu without pad, +18 dBu with pad
- Maximum output level: +22 dBu without pad, +19 dBu with pad
- High-pass filter: discrete, 12 dB/octave, 20–315 Hz
- Mains: 100–240 V, 50–60 Hz
- Dimensions: 483 × 260 × 44 mm (1U), weight 4.3 kg
