0-1
Always be curious and keep exploring.
0Hz
Completely annihilated, utterly silent.
Bill li
To understand the mysteries of sound and energy conversion from multiple dimensions
Evolution of power amplifier switching frequency
This concept doesn't exist for Class A and Class AB amplifiers operating in linear single-stage power supply topologies. Due to the continuous innovation in power amplifier topologies aimed at improving efficiency, a directly related parameter is the "operating frequency/switching frequency." This is an inevitable consequence of power amplifiers evolving from amplifying sine waves to amplifying pulsed square waves. Consequently, the operating frequency has increased from 0-20kHz in Class H amplifiers to 1MHz in the Shengfang STUDIO series Class D power amplifiers.
sound
Sound is produced by vibration. The same sound source will produce different sounds depending on the medium it passes through. Therefore, it can be said that no two sounds in the world are the same. The following phenomena, before being properly explained, are referred to as "sound mysticism."
"Sound flowing through the same conductor produces different sounds depending on the direction of the flow."
In the audio industry, no one could answer this question for a long time. But Shengfang knew: it's because grain boundaries exist in the crystal structure of conductors. When electrons pass through grain boundaries from different directions, the magnitude and direction of the resistance they encounter vary, manifesting in several ways: 1. slowing down passage, 2. preventing passage, 3. refraction. Since sound is directly related to the vibration of the propagation medium, these vibrations generated on the conductor must also be included in the factors that produce new sound.
Evolution of power amplifier testing standards
The testing standards for power amplifiers have evolved along with changes in amplifier topology. Generally speaking, the testing has transitioned from continuous RMS sine wave power to pulse signal power. This testing method is based on the signal and energy spectrum characteristics of music, with auditory perception as an auxiliary parameter. This new testing method more directly reflects the amplifier's rapid energy release capability and is closer to the original characteristics of sound.
IEC 60268.3-EIA/CEA-490-A
Evolution of Device Packaging and Materials
As application demands for power amplifier output power, size, and weight spiral upwards amidst conflicting requirements, the intersection of these demands becomes increasingly smaller. The continuous increase in frequency drives ever-smaller package sizes and shorter, even nonexistent, pins. The parasitic capacitance of the PN junction in the material must also decrease, as must the on-resistance. All of this is in pursuit of higher operating frequencies.
Evolution of power amplifier topology
The evolution of amplifier topologies has progressed from Class A to Class AB to Class H to Class TD/I to Class D, and then to Class D+H. All of this has been aimed at improving efficiency, reducing heat generation, minimizing size and weight, while simultaneously delivering greater power output and, of course, better sound.
Evolution of power amplifier power supply operating frequency
Power amplifier power supplies have evolved from initial linear power supplies to more efficient, lighter, and smaller switching power supplies due to considerations of efficiency, size, and weight. The AC-DC (PFC) frequency of the power supply has increased from 50Hz to 48kHz and then to 96kHz. The operating frequency of the DC-DC section of the power supply has also increased from 96kHz to 768kHz.
who I am
李达标 「Bill li」
Graduated from Nanhai Shimen Middle School in 1986.
Graduated from the Department of Applied Electronic Technology Engineering, Foshan University in 1989.
After that, I worked as a disco DJ and sound engineer for live bands for three years.
I entered the professional audio industry in 1992 and have served as an agent for well-known European and American professional audio brands such as JBL, BOSE, EAW, QSC, CROWN, Soundcraft, RCF, Celestion, and Sennheiser.
In 1998, he founded "SOUNDSTANDARD Factory" and established the SOUNDSTANDARD brand.
In 2004, SOUNDSTANDARD Audio Equipment Factory changed its name to "SAE AUDIO."
In 2025, he left SAE Performance Equipment Manufacturing Co., Ltd.
In the same year, he founded "Sound Foundation." and Sound Foundation Audio is the name of the factory and also the new brand.
SF owns the right to use the following trademarks: VERITY AUDIO, SOUNDSTANDARD, SAE, FAMOUSOUND, AES, SOUNDARD, LEXPRO.
You will also see the trademark "Dark Matrix future industry" on our product packaging, silkscreen printing, and advertising materials. This is the name of our unmanned factory. Many of our future products will be manufactured by this company.
"My goal has always been to create the best, most respected company on Earth that makes people's lives better."
Audio design is
「Use the tangible to create the intangible, use reality to create sensation.」
