Soulnote M-3 Monoblock Power Amplifier

Newly incorporated industrial grade can-type output transistors to achieve a perfect non-negative feedback single push-pull structure. Monoblock power amplifier that lets high-end speakers around the world provide playback bursting with emotion.

One push-pull output stage with 4-stage Darlington can-type transistors.
Single-ended and single-pull outputs were essential for creating an emotional musical experience, thereby eliminating the "microscopic time-domain blur" so often symbolized by the improvement in sound quality due to high-quality clock frequencies.

In M-3 we feature industrial grade output transistors with relatively low Cob and high current. The driver stage uses the same output stage transistors as the A-2, allowing these high-capacity banks to be easily driven in a total of four stages of the Darlington design.

Busbars with copper plate radiators
The main heatsink uses small, lightweight copper plate heatsinks - a rarity in conventional high power amplifiers. This heatsink also acts as a bus to power the can transistors, while the can transistor terminals run through the bus and are mounted directly on the board below it. This eliminates wiring—the Achilles heel of can transistors—and also eliminates inductor component instability and audio quality degradation caused by insulation sheet dumping in the device. Additionally, the heatsink is physically isolated from the chassis, which significantly impacts aspects of sound quality such as transparency and openness. Thus, this radiator kills three birds with one stone.


M–3 White Pages

Voltage amplification stage

The voltage amplification stage employs non-negative feedback differential circuits (new Type-R circuits) redesigned for power amplifiers. Only a single transistor is used to fully amplify the emitter follower, voltage, and differential circuits without any gain. The load impedance in this transistor is a "GND one-stage amplification single-end non-negative feedback circuit" that connects only to the GND. These new Type-R circuits were created using only 4 bipolar junction transistors and 10 resistors to extract ideal full swing output across a wide spectrum, even though this configuration is primarily the same as that used for single ended tube amplifiers. This ideal non-negative feedback circuit could easily be dubbed a reference circuit for how well it performs.

Extremely simple construction

The M-3 is where we discovered that large current power amplifiers should be dedicated to a single function. It features just one set of input terminals and speaker terminals. It is a single-function monoblock power amplifier with no selectors or attenuators. The signals input from the XLR terminals travel directly to the base of the first stage transistors, undergo single stage amplification, and are output via a single push-pull circuit. The only available operation is the power switch. As expected, the unit contains no unnecessary circuits or components like microcontrollers, etc.

Ultra-low loss 1600 VA non-epoxy resin-filling toroidal power transformer

Large power transformer that can be carried by one person alone.

High-speed non-negative feedback power supply

The commutating capacitors use specially selected 470 uF high resistance, small capacity, low magnification foil filter capacitors. Optimizing capacity according the number of capacitors used and minimizing the power supply load further improves real regulation in this heavy-duty power supply transformer. The rectifier diode uses newly adopted SiC diodes with the latest specs that reinforce the maximum input current value. This creates an unimaginably powerful and fast power supply structure.

Amplifier container completely separate from the main body, each grounded by three spikes

Three spikes ground both the main body and the amplifier container for a total of six spikes in the M-3. While these two components are completely physically separate, the power supply line from the power supply transformer has been shortened to eliminate any negative impacts as a result of vibrations and leakage from the transformer. This truly ideal construction results in an incredulous sound quality that can be experienced by attaching or removing the transportation screw. And of course, the audio board, AC adapter, speaker terminals, input terminals, and base plate are all non-rigid parts.

Ultra-low loss 1600 VA non-epoxy resin-filling toroidal power transformer

Large power transformer that can be carried by one person. This giant power transformer is mounted vertically on the front panel so that any leakage flow runs parallel to the PCBs, and is also suspended by titanium washers and connected to the spike to ensure that harmful vibrations are not transferred to the chassis.

Power Design by Soulnote M–3

The current line-up Soulnote is based on new design concept.


Maximum output

160W (4Ω)

Total harmonic distortion

0,1% (1W)

Frequency characteristic

2Hz ~ 200kHz (±1dB)

Input sensitivity / impedance

1V / 25kΩ



Power voltage

230V AC 50Hz

Power consumption


Maximum external dimensions

Main unit: 340(W) × 251(H) × 512(D)mm



Included accessories

Special speaker cable, Special rack, Power cable

Materials PDF / Downloads

Click on the links below to download documents:

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