【C-FOUR｜An AB-Class Power Amplifier That Brings Out a Natural, Powerful Sound】

For those who want to focus on the richness of the sound and the speaker’s drive capability.

C-FOUR is an AB-class power amplifier developed by inheriting BRAX power amplifier design philosophy. It is a model aimed at producing a natural sound that is easy to listen to without causing listening fatigue, while clearly extracting the amount of information in the audio. It is well-suited for anyone who wants to enjoy vocals and instrumental character with care.

The amplification stage uses a MOS-FET 4-parallel configuration. Because it has the power to drive speakers properly, it delivers a strong center and a sense of stability not only when you turn the volume up, but also at everyday listening levels.

The power supply section combines a large toroidal transformer and high-capacity capacitors, in addition to a MOS-FET 3-parallel configuration. For an amplifier, the power supply is the foundation of the sound. With this part well-designed and built, the sound’s foundation is less likely to wobble, and the speakers’ performance becomes easier to bring out.

In addition, the design prevents the amplifier from turning off even if the supply voltage drops for a short period of time, helping to address audio dropouts that are commonly experienced in vehicles equipped with an idling stop function.

To get the most out of C-FOUR, it’s important not only to consider the amplifier’s standalone performance, but also the way it is combined with speakers and a subwoofer, how the power is taken, wiring treatment, mounting method, and in-cabin adjustments. Even with the same amplifier, the final result varies depending on how it is integrated.

At Log On, we propose system configurations in which adding C-FOUR makes sense—taking into account your current system, your preferred sound, and the music you usually listen to. If you’d like a bit more body and roominess in your current sound, or if you’ve replaced your speakers but also want to be particular about drive power, please feel free to consult us. If I were advising you, I would first look at your vehicle and current system, and then speak honestly about whether it’s worth allocating budget to the amplifier as well.

■ Main Specifications / Specs

【Basic Information】
Product name: C-FOUR
Type: AB-class power amplifier

【Circuit Configuration】
Output stage: MOS-FET 4-parallel configuration
Power supply section: MOS-FET 3-parallel configuration
Power transformer: Large toroidal transformer
Power capacitors: High-capacity capacitors

【Performance】
Frequency response: 10 Hz to 80 kHz
S/N ratio: 112 dB
Damping factor: 1,000 or higher
THD (distortion rate): 0.007% or lower

【Other】
Protection against audio dropouts when the supply voltage drops: Design that keeps the amplifier from turning off even during short-term supply voltage drops
Response time: Approximately 5 seconds

*The actual configuration and mounting method will vary depending on the vehicle specifications and your current system. If you’d like to think together about sound tuning using C-FOUR, please consult us with your vehicle model and your current audio configuration.