Soulnote A-1 Integrated Amplifier

Perfectly balanced, discrete non-NFB circuits

To extract the best from the unique characteristics of SOULNOTE’s original perfectly balanced, discrete non-NFB circuits, we re-examined every minute detail of our amplifiers for possible improvements, like incorporating ground plane star wiring, centralizing local non-NFB regulators, implementing direct coupling routes, optimizing the tuning of the drive current, and more. This helped us achieve even more vibrancy and speed while also providing a wider sound range.

High-speed, discrete non-NFB power supply

In addition to a newly developed bifilar wound, large capacity toroidal transformer with independent positive and negative windings, we have lowered the impedance by connecting multiple high-voltage, small-capacity filter condensers in parallel and incorporating a fast recovery rectifier diode. We have also completely refined the smallest details in order to boost the power supply, such as making current loops as short as possible by placing the rectifier diode close to the power transformer. This further increases S/N and speed.

Contactless wiring

Every type of connector in the signal system has been eliminated to create a completely contactless construction. A three-dimensional print board assembly results in lower impedance in the power supply lines and wiring that focuses on star wiring. This improves S/N and removes any concerns about contacts deteriorating over time.

Output transistor pairing

The output transistors feature low Cob, high Ft, and have extreme accuracy. We have selected and paired these components based on their characteristics. They work together to increase sound image focus and deepen three-dimensionality.

Relay-switching balanced attenuator

The volume control in the A1 does not use a conventional rotary or electronic volume control. Instead, it uses a newly developed relay attenuator style balanced configuration. This dramatically increases clarity, and allows the sound image to emerge in three dimensions. It also significantly improves quality at low volume levels without fear of gang errors.

Direct mechanical grounding construction

Spikes connect to the bottom of the transformer’s center of gravity to directly expel harmful vibrations without interfering with the unit housing itself. This achieves both supremely vibrant musical expression and a high S/N.

Symmetrical housing with resonance control

The housing’s symmetrical construction increases rigidity balance while controlling the sharpness of resonance (Q factor). This eliminates the usual sensation of sound containment in highly rigid systems and creates the high resolution, expansive SOULNOTE sound. The newly developed, heavyweight aluminum front panel design also helps control resonance.

Metallic insulators as standard equipment (when under load)

Though plastic insulators are the conventional standard, we now use metallic insulators since they promote higher sound quality.