SPL Crescendo - Eight-Channel Microphone Preamplifier

The Crescendo is the first microphone preamplifier that works with an internal operating voltage of 120V and breaks new ground.

The Undistortable
Imagine a microphone preamplifier with such a wide dynamic range and high overload resistance that the entire dynamic range of the microphone can be recorded without any limitations. Imagine that the preamplification electronics themselves have no effect on the sound and you rediscover the sound of your microphones. With absolute signal fidelity and clarity.

VU -10
In the Crescendo, high gains can be used to optimally drive subsequent AD converters. Should the VU meter therefore deflect too far, you can reduce the displayed level by 10 dB.

48 V
The phantom power required for the use of condenser microphones is activated with the 48V switch.

Phase
Turn the polarity of a microphone signal 180° by activating the polarity reversal switch.

Pad
For loud input signals (including line signals) the input sensitivity can be reduced by 20 dB.

Mic Gain
The gain is adjusted by a 12-step switch. The pre-amplification ranges from +18 dB to +70 dB.

Inputs 1 - 8
The input differential amplifiers are constructed with pairs of transistors, each of which is combined in a housing. Precise matching of the transistors and thermal coupling ensure high common-mode rejection and extremely low THD values.

The choice of transistors and resistors has a decisive influence on the sound. In countless listening sessions the optimal components for Crescendo were selected - the effort was worth it!

Outputs 1 - 8
120V SUPRA operational amplifiers work as current amplifiers, which also offer pure class A operation with over 6mA quiescent current. We largely dispense with coupling capacitors in order to avoid their sonic disadvantages (diffuse, sloping, loss of dynamics). In order to eliminate DC voltage components nevertheless, active servo circuits are used.

Alternate DB25 Output
For fast cabling to multi-channel converters, Crescendo offers DB25 connection.

The 120V technology
The 120V technology is our reference technology. The 120V technology is unique in the world. It operates at a DC voltage of 120 volts. This is four times that of IC-based semiconductor op-amps.

The highest possible audio quality requires the highest possible audio operating voltage. The 120V technology works with +/-60 V. To be able to handle such a high voltage, we have developed special proprietary operational amplifiers that can operate with a DC voltage of +/-60 V: the SPL 120V SUPRA operational amplifiers. This high voltage would destroy conventional components and operational amplifiers.

The 120V technology achieves exceptional technical specifications and sonic benefits. Technically, in terms of dynamic range, signal-to-noise ratio and headroom. Sonically, in terms of richness of detail and an absolutely relaxed listening experience.

By the way, the "120V" in the name of the technology has nothing to do with the local mains voltage from the mains power socket. This is about the operating voltage inside the device with which the audio signals are processed.

The mains voltage from the mains power socket is transformed to the required secondary voltage in the device's internal linear power supply with toroidal transformer. Rectifiers convert this AC voltage into DC voltage required in the audio device.