SPL CRESCENDO DUO V2

120V Two-Channel Stereo Microphone Preamplifier

• Two channels of microphone preamplification featuring SPL 120V technology and proprietary SUPRA operational amplifiers
• Maximum output level of +32.5 dBu: a preamp that’s virtually impossible to saturate
• Gain from +18 to +70 dB via a step switch, plus ±10 dB output control for a total gain of 80 dB
• 48 V phantom power, polarity reversal, high-pass filter, -20 dB PAD, and VU meter with a -10 dB scale on each channel
• Dual parallel outputs per channel: built-in splitter for backup recordings
• V2 version with new black SPL Studio design, redesigned chassis, and additional gain settings in the midrange

The SPL Crescendo Duo V2 is a two-channel stereo microphone preamp that combines the sonic precision of the German broadcast tradition with SPL’s 120V technology, the manufacturer’s benchmark for its high-end products. The result is a preamp with a sound that is rich in detail, vivid, and at the same time natural, designed for recording studios, stereo recordings, and sessions where every nuance of the source must reach the converter intact.

SPL 120V Technology: Uncompromising Headroom for the Microphone Preamp

Most audio devices operate at internal voltages of ±15 V and handle a maximum of approximately +21.5 dBu. SPL’s 120V circuits, however, operate at ±60 V, thanks to proprietary SUPRA operational amplifiers developed specifically to handle these voltages. The Crescendo Duo thus achieves a maximum output level of +32.5 dBu, with approximately 12 dB more headroom than conventional circuits: the components always operate within their optimal range, and even the most intense transients from vocals, drums, and brass pass through without distortion.

From Mastering Consoles to Studio Preamplifiers

The concept behind 120V technology and SUPRA operational amplifiers originated in the 1990s with Wolfgang Neumann, founder and chief designer of SPL, with the goal of building a reference mastering console. The first application was the SPL MMC1, built in 2000 for Galaxy Studios, followed by the PQ parametric equalizer. Since then, the 120V has been the foundation of all SPL premium products, and the Crescendo Duo brings this same architecture to microphone preamplification.

Two complete channels for mono and stereo miking

The Crescendo Duo’s two channels offer the same features and allow you to work with two independent sources or a stereo pair: overheads, room mics, piano, acoustic ensembles, or a pair of small-diaphragm condenser microphones in an XY or ORTF configuration.

Gain from +18 to +70 dB with a stepped switch

Gain is adjusted using a large step switch ranging from +18 to +70 dB, ensuring precise and perfectly repeatable settings between channels—a decisive advantage in stereo recording. In the V2 revision, the switch offers a wider range of values in the mid-gain range—the range most commonly used in the studio with large-diaphragm condenser and dynamic microphones on medium-volume sources.

±10 dB output control to match your D/A converter

The switchable output control adjusts the level by ±10 dB, bringing the total gain up to 80 dB. In practice, you can precisely adapt the Crescendo Duo to the sensitivity of your AD converter, making the most of its dynamic range without risking clipping.

Channel functions: phantom power, filter, PAD, and VU meter

Each channel features 48 V phantom power for condenser microphones and 180° polarity reversal, useful for correcting phase issues in multi-microphone setups. The 6 dB/octave high-pass filter reduces unwanted low frequencies below 120 Hz, while the PAD lowers the input sensitivity by 20 dB for very loud sources; with the PAD engaged, the Crescendo Duo also accepts line-level signals. The VU-10 button shifts the VU meter scale by -10 dB, allowing you to accurately read even very high levels.

Built-in splitter with two outputs per channel

Each channel has two parallel outputs: you can send the same signal to two different converters or recorders—for example, for a backup recording during a session or live performance—without needing an external splitter.

SPL Studio Construction of the V2 Version

The V2 revision adopts the black design of the SPL Studio series, featuring a 4 mm anodized aluminum front panel, machined aluminum knobs, and a redesigned powder-coated steel chassis. Many key components are mounted using through-hole technology, a choice that allows SPL to select components based on sound quality as well. The internal linear power supply with a shielded toroidal transformer rounds out a build designed to last.

SPL Crescendo Duo V2 Technical Specifications

• Type: 2-channel microphone preamplifier with SPL 120V technology
• Analog Inputs and Outputs: Balanced XLR, 2 parallel outputs per channel
• Microphone gain: +18 dB to +70 dB, step-selector switch
• Output control: ±10 dB (total gain up to 80 dB)
• Maximum output level: +32.5 dBu
• Input impedance: 10 kΩ
• Output impedance: 75 Ω
• Frequency response (50 dB gain, -3 dB): 20 Hz – 100 kHz
• THD+N (10 Hz – 22 kHz, 30 dB gain): 0.0036%
• THD+N (10 Hz – 22 kHz, 70 dB gain): 0.32%
• Noise (A-weighted, 150 Ω, 30 dB gain): -89.2 dBu
• Noise (A-weighted, 150 Ω, 70 dB gain): -51.7 dBu
• Equivalent Input Noise (EIN, 70 dB gain, 150 Ω): -121.7 dBu
• Common-mode rejection (1 kHz, 30 dB gain): 79 dB
• Per-channel functions: 48 V phantom power, polarity reversal, 6 dB/octave high-pass filter at 120 Hz, -20 dB PAD, VU-10
• Power supply: internal linear power supply with shielded toroidal transformer
• Audio electronics operating voltage: ±60 V
• Relay and LED operating voltage: +12 V
• Mains voltage (selectable): 230 V AC / 50 Hz; 115 V AC / 60 Hz
• Fuses: T 0.5 A (230 V), T 1 A (115 V)
• Power consumption: max 17.7 VA
• Dimensions (W x H x D): 482 x 88 x 300 mm (19" rack, 2U)
• Weight: 6.1 kg
• Shipping weight: 7.5 kg