Designed for audio engineers who want an absolutely clean, transparent, distortion-free tone when tracking microphone-based sound sources, the SPL Crescendo is an eight-channel preamplier. Exceedingly low distortion and noise are both made possible by the 120V rails, giving you up to 70 dB of gain without any signs of overdriving. Each channel can capture a frequency range of 20 Hz to 50 kHz with lots of dynamic range.
Each channel sports a gain knob, a 48V phantom power switch, a pad switch, a polarity-inversion selector, and a switch for reducing the level displayed on the dedicated VU meter. The unit as a whole sports eight inputs and outputs. Connections are possible via XLR I/O on each channel, or through DB25 connectors, should you want to route this unit straight into a compatible patchbay or ADC.
A transformerless design, Class-A operation in the output stage, and SUPRA op-amps facilitate not only a low-noise performance, but the ability to drive long cable runs on the output side without sonic degradation. A shielded power supply is built into the unit, which ensures noise-free operation from the power of this preamp.
Thanks to the 120 VDC audio rail, this preamp sports a large dynamic range, a low amount of distortion, and a neutral tone. This means you can capture the nuances of various sound sources without worrying about overloading the preamp.
The SPL SUPRA op-amps enable an internal operating voltage of ±60V, which makes the unit more than capable to amplify the fastest transients, the finest of details, and the complete frequency spectrum with almost inaudible distortion.
Mic Gain Knob
Use the gain knob for the setting of the pre-amplification to control a range from 18 to 70 dB. For high-level signals, which do not need to be amplified that much, you can use a PAD with -20 dB of attenuation. Thus the control range of the amplification is shifted to -2 to 50 dB.
Input and Output Stages with Low THD and CMMR
The differential amplifiers in the input stage are built-up with transistor pairs, consolidated in in a special housing. A precise matching of the transistors, as well as thermal coupling, guarantee high common mode rejection and very low THD values. The choice of transistors and electrical resistors has a massive impact on the sound.
Servo Circuitry and Output Stage as Current Amplification
The discrete op-amps of the output stage are able to drive long cable paths without any problems. The output stages operate as current amplification, which, with 6mA quiescent current, also provide Class A operation. SPL minimized the use of coupling capacitors to avoid their sonic disadvantages which include diffusion, blurring, and loss of dynamics. However, to eliminate DC voltage, active servo circuits are used.
Individual Controls per Channel
Each of the eight preamplifiers of the Crescendo provides its own VU meter, phase reversal switch, phantom power selector, -20 dB PAD switch, and 10 dB reduction switch for the display of the VU Meter's level.
Integrated Shielded Power Supply
The toroidal transformer power supply is integrated in the housing of the Crescendo. To avoid electrical interference from the power supply on the preamplifier, the power supply is shielded with a special Mu-metal sheet. The transformer itself is also Mu-metal encapsulated.