【SAD-100.4 Power Amplifier｜A Class D Amplifier That Shapes the Sound Base in a Compact Size】

You want your car audio to sound a bit more solid, but adding an amplifier takes up too much space. If that sounds like you, you should consider SAD-100.4.

The unit measures 172×55×230mm. It’s a compact digital (Class D) power amplifier with circuitry consolidated to enhance sound quality, designed to fit easily even in limited in-car space. Because it also takes low current consumption into account, it’s well suited when you want to improve the sound base without making the overall system too large.

A Careful Circuit Design That Supports Sound Changes

The input stage and filter sections use circuits designed with high sound quality in mind. For the PWM conversion drive section that affects the sound quality of the digital amplifier, it uses the op-amp MUSES8820.

In addition, the PWM conversion circuit employs a Japanese-made single-chip IC transconductance amplifier. With a configuration aimed at accurate signal conversion, it achieves low distortion and a high SN ratio, leading to stable operation while suppressing noise contamination.

When you add an amplifier, it’s not just that the volume gets louder; you may notice changes in the power that drives the speakers, the definition of the sound, and the overall cohesion of the music. Even if you want to tidy up the positioning of vocals and instruments a bit more, or you want more headroom when increasing volume, it’s worth considering while looking at the system as a whole.

Compact Design With Attention to Appearance

The unit has a matte black finish, giving it a calm, understated look even after installing it in the vehicle. It features a structure where removing the black plate reveals the adjustment panel—making the design look neat while also making necessary adjustments easier.

However, an amplifier doesn’t determine the final sound just by being installed. You need to consider the finished result, including how it’s paired with the factory audio and existing speakers, how power is supplied, installation methods, wiring handling, and the final sound tuning.

At LOGON, we’ll look at whether adding the SAD-100.4 makes sense together, after confirming your vehicle model, your current system, the music you usually listen to, and your sound preferences. If it were me, I wouldn’t decide based solely on the amplifier’s standalone performance; I’d build the configuration based on how it actually sounds in the car.

If you’d like to add a bit more power and stability to your current sound, or if you want to add an amplifier in a limited space, please show us your current system first. Rather than unnecessarily increasing the number of components, we’ll propose a form that’s less likely to leave you regretting your choices—while organizing where the cost should truly be invested.

■ Main Specifications

【Basic Information】
Product name: SAD-100.4
Type: Digital (Class D) power amplifier
Current consumption: Low-current design

【Circuit / Sound Quality Design】
Op-amp for PWM conversion drive section: MUSES8820
PWM conversion circuit: Japanese-made single-chip IC transconductance amplifier
Circuit configuration: Input stage and filter sections designed for high sound quality
Features: Low distortion, high SN ratio, stable operation with reduced noise intrusion

【Unit Dimensions】
Width: 172mm
Height: 55mm
Depth: 230mm