SOULNOTE M-3 Monoblock Power Amplifier

SOULNOTE M-3 Monoblock Power Amplifier

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

We decided that single-end and single push-pull output was indispensable in creating an emotional musical experience, thus eliminating the “blurring in the microscopic time domain” so often symbolized by improvements in sound quality through high-end clocks. Nevertheless, we still had to overcome the relatively low levels of current provided by the typical single push-pull configurations. As a result, in the M-3 we introduced industrial grade can-type output transistors with a relatively small Cob and large current flow. The driver stage incorporates the same output stage transistors used in the A-2 to easily drive these large capacity cans for a total of four Darlington construction stages.

The main heat sink uses small, lightweight copper plate heat sinks – a rarity in conventional high power amplifiers. This heat sink also doubles as a bus bar to power the can transistors, while the can-type transistor terminals pass through the bus bar and are mounted directly on the board underneath. This eliminates wiring – the Achilles’ heel of can-type transistors – while also removing instability from inductance components and deteriorations to sound quality caused by insulating sheet dumps in the device. Additionally, the heat sink is physically isolated from the chassis, which significantly impacts sound quality aspects such as transparency and providing a feeling of openness. This way, this heat sink kills three birds with one stone.

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-NFB 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-NFB circuit could easily be dubbed a reference circuit for how well it performs.

Manufacturer’s website SOULNOTE