SPL Audio Crescendo 8 Eight-Channel Microphone Preamplifier

About: SPL Audio Crescendo 8 Eight-Channel Microphone Preamplifier

Crescendo 8 combines the precise sound that German Rundfunk-Technik is famous for with the innovative SPL 120V technology. The internal operating voltage of 120 volts allows Crescendo microphone preamplifiers to break completely new ground. This results in microphone preamps that sound detail-rich, vivid and equally honest. Crescendo 8 lets microphones shine in a whole new light – because they have never been amplified like this before.

The Undistortable

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

Crescendo 8 is an eight-channel microphone preamplifier with 120V technology.
All eight channels feature the same range of functions. Besides phantom power (48 V) for condenser microphones, polarity reversal and a PAD switch, they provide the possibility to adjust the VU meter to display very high levels. The gain can be adjusted comfortably and precisely via a high-quality potentiometer. 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 8 convinces with a sonic authenticity that is second to none.

• Mic Gain - The gain is adjusted by an analog potentiometer. The pre-amplification ranges from +18 dB to +70 dB.
• 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.
• 48 V - The 48V switch activates the required phantom power of 48 volts for the use of condenser microphones. The red LED indicates that the phantom power is active.
• Ø - Activating the polarity reversal switch turns the polarity of a microphone signal by 180°.
• PAD - By activating the PAD switch, the input sensitivity can be reduced by 20 dB. This allows the preamplifier to be ideally adapted to high level input signals.
  • Tip: With PAD activated, Crescendo 8 also works perfectly with line-level input signals.

Built-in Output Splitter

All eight microphone preamps have two parallel outputs each. This allows the signal to be sent to two different devices in parallel. One output each is available as XLR line output. The respective second outputs are available as a DB25 jack. These can for example be ideally connected to a multi-channel AD converter, with the for this kind of device type typical DB25 input. An additional external signal splitter for back-up systems during a recording session is therefore no longer necessary.

Perfection in detail

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 paid off!

More sound through innovation

Our 120V SUPRA operational amplifiers work as current amplifiers, which also offer pure class A operation with over 6 mA 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 active servo circuits are used.

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.

The idea for SPL 120V technology and the SUPRA operational amplifier based on this technology were developed in the 1990s by SPL founder and chief developer Wolfgang Neumann.

With the goal of building the best mastering console ever, this basic technological philosophy then took shape for the first time – thus the SPL MMC1 Mastering Console for Galaxy Studios saw the light of day in 2000.

The outstanding sonic and technical features quickly got around in the scene – so further orders were not long in coming.

Besides the MMC 1, another legendary product with 120V technology was created with the PQ, the “King of Parametric Equalizers”.

Since that time, 120V technology has been the foundation for all SPL premium products. Meanwhile, not only for mastering applications, but also for the, studio or hifi use.

Comparison

Most audio devices work with an internal operating voltage of +/-15 volts and can thus process a maximum input level of +21.5 dBu. If a DAC, for example, has an output level of +22 dBu at 0 dBFS, level peaks of the music material would already cause overloads in the input stage of the device.

All components in the audio device often operate at their limits. The result is an unsteady sound that causes stress and faster ear fatigue.

SPL devices with 120V technology can handle input levels of +32.5 dBu thanks to the higher internal operating voltage of +/- 60 volts – thus offering 12 dB more headroom. All components consequently operate continuously in the optimum operating range. The result is a very pleasant, natural and relaxed sound experience. So you can enjoy your music in every detail.

Looks great, feels great – and lasts for a lifetime

The Crescendo 8 has a 4 mm thick, black anodized aluminum front panel and aluminum knobs milled from solid. The housing is made of high-quality steel and is powder-coated in elegant black.

Sounds good

With all SPL devices we develop not only according to plan, but also by ear. All important components are installed on the circuit boards using Through-hole technology. This way we can ensure that we can use the best sounding components.

Specifications

• Analog input & output; XLR (balanced)
  • Maximum output level -  32,5 dBu
  • Input impedance -  10 kΩ
  • Output impedance -  75 Ω
  • Frequency range (30 dB Gain) -  20 Hz – 100 kHz
  • THD + N (30 dB Gain) -  0,0089 %
  • THD + N (70 dB Gain) -  0,30 %
  • Noise (A-weighted, 150 Ω, 30 dB Gain) -  -90,8 dBu
  • Noise (A-weighted, 150 Ω, 70 dB Gain) -  -57,8 dBu
  • Equivalent Input Noise, EIN (150 Ω) -  -127.8 dBu
  • Common mode rejection ratio (CMRR, 30 dB Gain) -  >84 dB
• Internal Linear Power Supply with Shielded Toroidal Transformer
  • Operating voltage for audio electronics -  +/- 60 V
  • Operating voltage for relays and LEDs -  + 12 V
• Mains Power Supply
  • Mains voltage (selectable, see fuse chamber) -  230 V AC / 50; 115 V AC / 60 Hz
  • Fuse for 230 V -  T 1,6 A
  • Fuse for 115 V -  T 3,15 A
  • Power consumption -  230 V: 60 W, 115 V: max. 60 W
• Dimensions & Weight
  • W x H x D (width x height x depth) -  482 x 132 x 300 mm / 19 x 5.2 x 11.8 inch
  • Unit weight -  9.5 kg / 20.94 lbs