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XPS Series

Class-DH Switch Mode Power Amplifiers with Crossover and OVP Power Converter

The XPS-series amplifiers are two-channel class-DH amplifiers at a compact size of 2 HU (rack spaces). All models are equipped with a high-efficient SMPS (switch mode power supply), which ensures top performance and light weight. The front panel shows two gain controls for easy access and the main switch. Two round LED displays inform about the condition of the amplifiers. The rear side shows two XLR input connectors and two XLR output connectors (link). The input sensivity (gain) is 32 dB. Two SPEAKON© outputs and four binding posts are mounted at the rear side. The SPEAKON© connector of the output channel 1 (left) is connected with all four poles. This connector offers additionally the output signal of channel 2 (right) at the pins 2 123123123

Sounds like "Class-H" - Efficient like "Class-D“
A class-H amplifier is basically a class-AB amplifier, the supply voltage can be changed in dependence on the signal. At high power output levels of the amplifier, the class-H design is used to reduce the voltage drop and dissipation power in the output transistors considerably. The voltage increase is split at class-H amplifiers in 2 or 3 stages in the power supply. Disadvantages of class-H are the higher circuit complexity and low distortion when switching to the higher voltage level. The efficiencies of class-H amplifiers are between 60% to over 80%, depending on the circuit design.
Dynamic adaptive voltage regulator
Class-DH is the evolution of the class-H technology. Class-DH has all the advantages of the class-H technology, but without switching to any higher or lower voltage level(s). Class-DH amplifiers are equipped with a dynamic adaptive voltage regulator that regulates the supply voltage continuously. The usually occuring distortion when switching to the higher supply voltage, is typically for class-H amplfiers. This kind of distortion does not occur in class-DH amplifiers at all. The efficiencies of the class-DH amplifiers are over 90% at

Advantages class-DH:
► Distortion-free sound due to continuous control of the supply voltage
► Higher efficiency and less power consumption
► Less heat by very low power loss

POWER CONVERTER - Full Output Power at any Impedance
In theory, an amplifier that delivers 500 watts into an 8-ohm load, offers analogous to Ohm's law 2.000 watts to a 2-ohm load. In practice, many amps deliver 65% -77% of the theoretical 4-ohm power at 2 ohms only. The resulting losses come from the voltage power supply and from the current limitations of the output stages. The current limiter in the output stage generates additional distortion, which has to do with the impedance curve of the loudspeaker connected. The speaker represents a dummy load to the amplifier. A large part of the energy is returned to the amplifier and may activate the current protection circuit (current limiter) externally.

The OVP Power Converter
The NOVA Over-Voltage Protection (OVP) is a special power converter that can deliver more power than it has previously taken from the power supply. Due to this, it delivers the required current even at lower impedances. To drive a higher impedance (such as a speaker with an impedance of 8 ohms) a higher voltage is required. Using the OVP switch (not in XPS 900 model), the user can adjust the NOVA XPS amplifiers exactly to the impedance of the loudspeaker connected.

Advantage OVP:
► Full power output even at low impedances

Advantage of X-over function:
► High flexibility and cost-effective configuration
   of smaller systems

For larger and more complex speaker systems, we recommend using a digital loudspeaker management system, which takes over the function of a crossover. For smaller systems, such as a system consisting of two 18" subwoofers and two 2-way mid/high loudspeakers, the users often rely on cost efficiency and flexibility. Therefore, all NOVA XPS amplifiers are equipped with a high pass filter (120 Hz / 18 dB / Butterworth) and a low-pass filter (120 Hz / 18 dB / Butterworth). The x-over filter type can be selected on the rear side of the XPS amplifiers by using a switch. The crossover function is disabled in position FULLRANGE.

The core of the NOVA XPS amplifiers is the variable SMPS switching power supply, which provides stable performance even with voltage fluctuations in the mains supply (~230V  10%). The power supply is designed specifically for the NOVA class-DH amplifier technology. It provides a stable power supply for uncompromising performance even at full load and low-impedance. The use of this highly efficient power supply also leads to a very low weight of the XPS power amplifiers.

Advantages of variable switching power supply:
► Stable performance at full load & fluctuating voltage from the mains supply
► Stable bass reproduction even at full load
► Lightweight

Safety circuits
The comprehensive package of safety circuits protects the connected speakers and periphery in case of trouble. All NOVA X-series amplifiers are equipped with following safety circuits:

Back EMF protection
Speakers are a complex and reactive load for an amplifier. Because of the high damping factor of all NOVA amplifiers the EMF effect figures not during normal operation. In case of a defective speaker the energy could be sent back to an amplifier. This energy is very high and could destroy parts like transistors of an amplfier without back EMF (Electro-Motive-Force) protection. All NOVA amplifiers are equipped with a back EMF protection and protect from those damages.

Short circuit protection
A short cicuit in a speaker or cable could destroy the transistors of an amplfier. All NOVA amplifiers are equipped with a short circuit protection. This protects the amplifier from those damages.

Overheating protection
All NOVA ampifiers are equipped with sensors at the transistors and transformers. Because of permanent monitoring of temperature the built-in fans make sure of sufficient cooling.

HF protection
Extremely high frequencies could destroy the voice coils of the connected loudspeakers. All NOVA amplifiers are equipped with HF protection circuits and filters.

DC protection
DC (direct current) at amplifiers output could destroy the voice coils of connected loudspeakers. All NOVA amplifiers are equipped with DC protection circuits, which avoid DC at the outputs of the amplifiers.

Technical Data
Any current NOVA product may differ in some respect from its published description, but will always equal or exceed the original design specifications unless otherwise stated.

  Product Pictures XPS900 Picture 1
    XPS1400 Picture 1
    XPS2000 Picture 1
    XPS3000 Picture 1
    XPS3600 Picture 1
    XPS Series Picture 1
    XPS Rear View Picture 1
    XPS Series 3D Picture 1
  Engineering Data Sheet n/a
  Technical Drawing XPS Series
  User Manual XPS Series
  Audio File Burst signal for lab measurement use (.WAV audio file)