Pioneer M-AX10

Commentary

A dual-drive amplifier developed in anticipation of the DVD audio age as a culmination of the direct energy MOS FET developed by Pioneer.

Equipped with a 4-channel power amplifier, 3-mode speaker drive system can be selected.
In separate mode it operates as a 4-channel independent power amplifier, in dual mode it operates as a bi-wired connection to eliminate interference between speaker units, and in bridge mode it operates as a 2-channel high power amplifier with a bridge connection.

Equipped with Direct Energy MOS FET developed by Pioneer.
Direct Energy MOS FETs have excellent power linearity and low-load drive capability with extremely low energy loss. By increasing the capacity of these power elements and using only selected high-quality products for all channels, operating errors between channels are completely eliminated.
In addition, by using a ceramic sheet with extremely low thermal resistance as an insulating material between the large heat sink and the MOS FET, the temperature rise in response to the connection signal input and the instantaneous temperature rise in response to the pulse input are minimized, and the response speed and sound transparency at the time of a large volume input are improved.
In addition, a newly developed Z-bias circuit that controls the temperature coefficient of the MOS FET for temperature compensation of the idle current is incorporated, and the drift of the idle current is greatly reduced, and stable sound quality is realized immediately after power is turned on.

By further brush-up the wide-range linear circuit which can obtain the necessary gain by the current feedback type one stage amplifier circuit, the complete discrete configuration without using DC-servo or operational amplifier is realized. By keeping the NFB constant from the ultra-low range, clear low-range reproduction is possible.

The volume is equipped with a Digital Accurate Control Attenuator that uses ultra-precision resistance elements in the D/A converter to control the volume with high precision. Two input switches and DAC attenuator function allow direct input from a CD player or other device.
The DAC attenuator has features such as no linkage error between the left and right channels, no deterioration of SN ratio or separation due to the attenuator position, and no influence of vibration.
You can also use the attenuator through function when connected to a preamp.

Newly developed low impedance electric field capacitors and thick wires are frequently used for power supply and ground lines, and Ultra Low Instance power circuit with low impedance is adopted to improve the ability to supply instantaneous large current.

A left and right independent twin stereo configuration is used from the power supply to the input / output terminals on the rear panel.
In addition, by simplifying and shortening the signal path and isolating each block with a shield case, we thoroughly analyze the potential difference inside the chassis, magnetic field inside the set, temperature, vibration, etc., and homogenize the environment.

Newly developed thick-walled aluminum extruding material independent on left and right is used for the heat sink.
Three brass stays made of solid brass are combined in a hybrid construction to hold heavy objects such as power transformers, electric field capacitors, and heat sinks, thereby increasing component rigidity.

In order to protect the input and output terminals from the sound pressure of the speakers, a copper-plated 2 mm thick steel plate is used as the rear stabilizer, and solid brass is used as the insulator to control vibration.

The chassis, rear panel, shield case, etc. use high conductivity chassis made of copper plated steel plate to suppress high-frequency noise.
In addition, each part is carefully selected, and the sound quality is examined by the set mounting.

The power supply section is equipped with a large 355 VA super-ring toroidal transformer to improve low-load drive capability.
We have also cleared the power source harmonics regulation, which has been considered difficult for large-capacity toroidal transformers.

Model Rating

Type	Dual drive amplifier
Rated output (all channels driven)	2 x 230 w / 2 x 220 w (1kHz/20Hz to 20 khz, 0.15%, 6 Ω, Bridge) 2 x 200 w / 2 x 190 w (1kHz/20Hz to 20 khz, 0.09%, 8 Ω, Bridge) 115Wx4/110Wx4 (1kHz/20Hz ~ 20 khz, 0.15%, 3 Ω, Dual/Separate) 100Wx4/90Wx4 (1kHz/20Hz to 20 kHz, 0.09%, 4 Ω, Dual/Separate) 65Wx4/60Wx4 (1kHz/20Hz ~ 20 khz, 0.08%, 8 Ω, Dual/Separate)
Total harmonic distortion factor	0.08% (20 Hz-20 kHz, 100W, 8 Ω, Bridge) 0.06% (20 Hz-20 kHz, 30W, 8 Ω, Dual/Separate)
Frequency characteristic	5 Hz ~ 150 kHz + 0 -3dB
Signal-to-noise ratio	125 dB (attenuator through on)
Channel separation	115 dB (20 Hz to 20 kHz, Dual/Separate) 104 dB (20 Hz to 20 kHz, Bridge)
Damping factor	400(1kHz) 300 (20 Hz to 20 kHz)
Input Sensitivity / Impedance	Input1, 2 : 1V/47k Ω
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption	320W
External dimensions	Width 440x Height 178x Depth 420 mm
Weight	25.8kg