SPL Audio Crescendo duo

The Undistortable

Thanks to the SPL 120V technology, it is almost impossible to overdrive this microphone preamplifier.

Crescendo duo is a dual-channel microphone preamplifier with 120V technology.

Both channels feature the same range of functions. Besides phantom power (48 V) for condenser microphones, polarity reversal, a high-pass filter and a PAD switch, they provide the possibility to adjust the VU meter to display very high levels – so they leave nothing to be desired. The gain can be adjusted comfortably and precisely via a 12-step switch. With the switchable output control, the output level of the Crescendo duo can be perfectly adapted to following AD converters. Two outputs per channel allow the signal to be sent to two different devices in parallel. In addition to the extensive feature set and the outstanding technical characteristics, Crescendo duo convinces with a sonic authenticity that is second to none.

48 V

The 48V switch activates the required phantom power of 48 volts for the use of condenser microphones.

VU-10

With this switch the level displayed in the VU meter can be adjusted by -10 dB. This is very handy to display high levels.

Ø

Activating the polarity reversal switch turns the polarity of a microphone signal by 180°.

HP

A high-pass filter with 6 dB per octave reduces subsonic noise below 120 Hz.

Output

The switchable output control allows level adjustment to subsequent devices. The control range is +/- 10 dB. This results in a total gain of 80 dB.

Built-in Output Splitter

Both microphone preamps have two parallel outputs each. An additional external signal splitter for back-up systems during a recording session is therefore no longer necessary.

For audio professionals and enthusiasts who demand pristine sound quality and reliable performance, the SPL Audio Crescendo duo stands as an exceptional choice in audio interfaces. When capturing or processing audio, the integrity of the signal path is paramount, and this device is engineered to deliver ultra-clean, transparent sound with minimal distortion, making it indispensable for studio recording, mixing, and mastering environments where clarity and accuracy are non-negotiable.

The Crescendo duo features an internal linear power supply equipped with a shielded toroidal transformer, providing operating voltages of ±60 V specifically for the audio electronics. This design choice is not merely technical jargon; it means the interface delivers exceptionally stable and noise-free power. For users, this translates into reduced electromagnetic interference and hum, ensuring that the audio signal remains pure throughout the processing chain. The dedicated +12 V supply for relays and LEDs further isolates control electronics, preventing potential noise contamination. With selectable mains voltage options of 230 V AC at 50 Hz or 115 V AC at 60 Hz, the Crescendo duo is versatile enough to adapt to various international power standards, making it suitable for global studios.

Audio fidelity is further enhanced by the interface’s ability to handle a maximum output level of 32.5 dBu, which means it can accommodate professional-level audio signals without distortion or clipping. The input impedance at 10 kΩ is optimized to ensure the interface works seamlessly with a wide range of microphones and instruments, preserving the natural tonality of the source. Output impedance of 75 Ω guarantees compatibility with standard studio equipment and cables, maintaining signal integrity over long cable runs. The wide frequency range of 20 Hz to 100 kHz at 50 dB gain ensures that the Crescendo duo can reproduce the full spectrum of audible sound as well as ultrasonic frequencies, which is crucial for high-resolution audio work and for preserving the nuances in high-fidelity recordings.

Total harmonic distortion plus noise (THD + N) is impressively low, rated at 0.0036% at 30 dB gain and 0.32% at 70 dB gain. This means that even at higher gain settings, the Crescendo duo introduces negligible coloration or unwanted noise, allowing engineers to trust that the sound they hear is true to the original performance. The device’s noise floor is exceptionally quiet, with A-weighted noise levels of -89.2 dBu at 30 dB gain and -51.7 dBu at 70 dB gain, and an Equivalent Input Noise (EIN) of -121.7 dBu at 70 dB gain with 150 Ω load. This ultra-low noise performance ensures that even the most delicate audio signals are captured without interference, making it ideal for recording quiet sources or subtle details.

The interface also features a high common mode rejection ratio of 79 dB at 1 kHz with 30 dB gain, which effectively minimizes unwanted noise picked up from ground loops and electromagnetic interference. For professionals working in complex studio setups, this means cleaner recordings and fewer technical issues, reducing downtime and enhancing workflow efficiency. Despite its high-end specifications, the Crescendo duo maintains a manageable power consumption of just 17.7 VA, reflecting efficient design that keeps operational costs and heat generation low.

In practical terms, the SPL Audio Crescendo duo is a robust, precision tool for studios aiming to achieve the highest sound standards. Whether you are recording vocals, instruments, or mixing demanding projects, this interface provides the clarity and reliability necessary to elevate your productions. Its compatibility with international power supplies makes it a flexible option for touring engineers or studios with global reach.

Priced at ₹207,945, the SPL Audio Crescendo duo represents a serious investment in audio quality and professional craftsmanship. For audio engineers and producers who refuse to compromise on sound integrity, this interface delivers consistent, transparent performance that justifies its premium standing. Choosing the Crescendo duo means equipping your studio with technology that enhances your creative potential while ensuring every detail of your sound is captured with utmost clarity and precision.