British Company

MX Series Modular Power Amplifiers

The Myryad MXA Modular Power Amplifier format was conceived to provide a range of power amplifiers to suit all needs. The amplifier chassis can accommodate up to seven amplifier modules, each of which can be either 1 x 150W or 2 x 80W, so a single chassis can deliver up to 7 channels at 150W, or 14 channels at 80W – or any combination in between. 


Finish

Anodised Black fascia with Black casing Anodised Silver fascia with Silver-Grey casing

Introduction

The MXA Modular Power Amplifier features:
  • Up to 7 modules can be installed in one chassis, in any combination of 1 x 150Wand 2 x 80W modules, so one fully loaded chassis can deliver either 7 x 150W or 14 x 80W or any combination between
  • High output current design, supported by generously rated output transistors and reservoir capacitors and a massive (3.4kg) toroidal transformer in each module ensures smooth, effortless delivery of power
  • Each 80W amplifier uses two 150W output transistors, for robust, high current capability, and 14,000 µF of reservoir capacitors for dynamic power reserves. Each 150W amplifier uses four 150W output transistors and 20,000 µF of reservoir capacitors
  • The 150W amplifier uses Vishay bulk-foil and 0.1% tolerance feedback resistors for open, transparent and natural sound
  • 5 separately regulated power supplies for each amplifier channel ensure that all low level circuitry has clean, low-noise power, effectively isolated from the output stages
  • Each amplifier channel has its own processor monitoring temperature, output current and DC. Any deviation triggers isolation of its loudspeaker output and a status indication on the front panel display
  • Each channel has a line-out connector allowing easy “daisy-chaining” for bi-amping, tri-amping or multi-room applications
  • A sequenced switch-on system ensures smooth and silent power-up from standby, even when a full seven modules are installed
  • All amplifiers are fully upgradeable -  more modules can be added as needed after purchase
  • Distinctive elliptical Standby touch switch
  • LED indication of standby state
  • Additional LEDs indicate fault condition if amplifier protection is activated
  • Myryad “Smart My-Link®” for intelligent system operation with other Myryad products
  • Optically isolated remote DC trigger control input/output for standby switching
  • Balanced input version of 150W amplifier module available to special order

 


Finish

Anodised Black fascia with Black casing Anodised Silver fascia with Silver-Grey casing

 

Technical

1 x 150W amplifier module
The MX 150W power amplifier module employs a 3.4kg toroidal power transformer which feeds directly through ultra-fast rectifiers to 20,000µF of reservoir capacitors – produced by paralleled smaller capacitors to keep the supplies’ resistance and inductance as low as possible. In addition high-speed film capacitors are wired across the reservoirs to maintain low impedance at high frequencies. This impressive power source connects directly to the amplifier’s output transistors. A separate rectifier system feeds the power regulators for the amplifier’s sensitive input stages.

MX 150W power amplifier uses Myryad’s signature DC5* circuit configuration. The complementary push-pull class A input stage has an exceptionally wide bandwidth, combined with low noise and distortion. From here, the signal is passed on, via the complementary cascode stage, to the main class A gain stage. All of this low power circuitry is powered from low-noise, low-impedance, high isolation regulated power supplies. This ensures that these sensitive circuits are totally unaffected by any noise or distortion present on the high current supplies for the outputs.

The output stage uses the well-proven triple-emitter-follower configuration with a total of four 150W, 230V output transistors. The combination of these output devices and the generously rated power supply results in a peak output current in the region of ±75 amps.
The output signal passes through a high-current muting and protection relay before going on to the gold-plated 5-way binding post speaker terminals. The relay contacts only have a very small effect on the signal, but even this is removed by connecting the relay within the amplifier’s main feedback loop. The MX 150W amplifier uses an ultra-stable Vishay bulk-foil resistor (temperature coefficient  <4ppm/˚C) for its main feedback resistor to maintain dynamic linearity.

The DC output voltage is held down to a few millivolts by a DC servo that uses a low-noise high-speed  FET op-amp and high-speed polypropylene film capacitors. There is only a single high-speed coupling capacitor in the signal path – at the amplifier input.

*   Double Complementary Cross-Coupled Cascoded Current-mode feedback


2 x 80W amplifier module
The MX 2x80W power amplifier module employs a single 3.4kg toroidal power transformer with two separate secondary windings, each feeding directly through ultra-fast rectifiers to 14,000µF of reservoir capacitors – per channel. In addition high-speed film capacitors are wired across the reservoirs to maintain low impedance at high frequencies. This substantial power source connects directly to the amplifier’s output transistors. A separate rectifier system feeds the power regulators for the amplifier’s sensitive input stages. The power transformer is the only component shared by both amplifier channels. The secondary windings and all circuitry thereafter are separate for each channel, ensuring excellent separation and stereo imaging.
MX 80W power amplifier uses Myryad’s signature DC5 * circuit configuration. The complementary push-pull class A input stage has an exceptionally wide bandwidth, combined with low noise and distortion. From here, the signal is passed on, via the complementary cascode stage, to the main class A gain stage. All of this low power circuitry is powered from low-noise, low-impedance, high isolation regulated power supplies. This ensures that these sensitive circuits are totally unaffected by any noise or distortion present on the high current supplies for the outputs.

The output stage uses the well-proven triple-emitter-follower configuration with two 150W, 230V output transistors per channel. The combination of these output devices and the generously rated power supply results in a peak output current in the region of ±40 amps.
The output signal passes through a high-current muting and protection relay before going on to the gold-plated 5-way binding post speaker terminals. The MX 80W amplifier uses specially selected close tolerance main feedback resistor to maintain dynamic linearity.
The DC output voltage is held down to a few millivolts by a DC servo that uses a low-noise high-speed FET op-amp and high-speed polypropylene film capacitors. There is only a single high-speed coupling capacitor in the signal path – at the amplifier input.


*   Double Complementary Cross-Coupled Cascoded Current-mode feedback

 

Specification

1 x 150W Amplifier Module

 

Continuous rated power output                                   8W:

150W

                                                                        4W:

230W

THD (@80% rated power, 8W 20Hz-20kHz):

0.02%

Signal/Noise ratio (A weighted, ref. 150W):

>118dB

Frequency response (20Hz - 20kHz)

±0.2dB (-2dB @ 96kHz)

Input sensitivity (ref. 150W):

1.23 V

Input impedance

20 kW // 440pF

 

 

 

2 x 80W Amplifier Module

 

Continuous rated power output                                   8W:

80W

                                                                        4W:

120W

THD (@80% rated power, 8W 20Hz-20kHz):

0.02%

Signal/Noise ratio (A weighted, ref. 80W):

>116dB

Frequency response (20Hz - 20kHz)

±0.2dB (-2dB @ 96kHz)

Input sensitivity (ref. 80W):

900 mV

Input impedance

60 kW // 440pF

 

 

Physical Specification

 

Dimensions (width x height x depth)

436 x 190 x 479mm

Weight, Net.

Up to 44.0 kg (depending upon module complement)

 

 

Fascia

9mm thick bead-blasted aluminium anodised with silver or black finish