Rebec RPX-B680 – 6-Channel Class AB DSP Amplifier

Product Overview

The Rebec RPX-B680 is an integrated DSP amplifier from the RPX-B Series, combining digital signal processing with six channels of Class AB amplification in a compact unit.

Building on the entry-level concept of the RPX-B480, the Rebec RPX-B680 adds two amplifier channels, providing greater flexibility for speaker system configuration while retaining multiple analog and digital input options, PC/App tuning, and external amplifier expansion capability.

With its six built-in amplifier channels, the RPX-B680 can support configurations such as a 2-way active front stage with passive rear speakers, or a 3-way active front stage, making it a practical solution for users who need more channels within a single DSP amplifier.

Six-Channel Class AB Amplification

The Rebec RPX-B680 uses a Class AB amplifier architecture based on the TDA7851 and TDA7377 power amplifier ICs.

Channels 1–4 deliver 25W RMS per channel at 4Ω, while channels 5–6 provide 20W RMS per channel at 4Ω. At 2Ω, output increases to 40W RMS for channels 1–4 and 30W RMS for channels 5–6.

The six-channel configuration is an important distinction from the four-channel RPX-B480. The additional channels allow more speakers to be powered directly from the DSP amplifier, which can simplify the installation of active multi-way systems.

DSP Processing and System Tuning

Signal processing is handled by the AP1821 DSP processor operating at a 48kHz sampling frequency. The audio signal path also incorporates a CS4344 DAC and ES7210 ADC.

System adjustment can be performed through either PC or App, providing the tuning capability needed to configure the DSP according to the vehicle, speaker layout, and system design.

The RPX-B680 also provides eight low-level outputs at 2.35V. This allows processed signals to be sent to external amplifiers when the system requires additional power or a different amplifier configuration.

As a result, the RPX-B680 can operate as an integrated DSP amplifier for a relatively straightforward installation while still providing room for further system development.

Flexible Source Connectivity

The RPX-B680 supports both factory and aftermarket audio sources through a combination of analog and digital inputs.

Four high-level inputs supporting signals up to 26Vpp allow connection to factory audio systems, while two low-level inputs supporting up to 6Vpp provide an analog connection for compatible source units.

For digital audio, both Optical (Toslink) and Coaxial inputs support signals up to 96kHz. USB Audio 2.0 provides an additional digital connection, while built-in Bluetooth 5.4 supports wireless audio playback from compatible devices.

This range of input options provides flexibility when integrating the DSP amplifier into different vehicle audio systems.

More Flexibility for Active Speaker Systems

The addition of two amplifier channels gives the RPX-B680 more system configuration options than the RPX-B480.

One practical application is a 2-way active front system combined with a 2-way passive rear system. Four amplifier channels can be assigned to the front tweeters and midbass speakers, while the remaining two channels power the passive rear speakers.

Another option is a 3-way active front system, using all six amplifier channels to independently drive the left and right tweeter, midrange, and midbass speakers.

These configurations allow the Rebec RPX-B680 to support a more complete active front stage without requiring an additional amplifier for the six main speaker channels.

Compact Integrated Design

Despite the additional amplifier channels, the RPX-B680 maintains compact dimensions of 167 × 117 × 43 mm.

DSP processing, six-channel Class AB amplification, digital and analog source connectivity, Bluetooth, and USB Audio are integrated within the same chassis. This reduces the number of separate components required for a DSP-based car audio installation.

External amplification can still be incorporated through the processed low-level outputs if the system is expanded later.

Sound Performance

The RPX-B680 is designed with a focus on high-resolution sound and accurate tuning. Its DSP platform provides the adjustment capability required to optimize the system according to speaker configuration and the acoustic environment inside the vehicle.

Rather than focusing on high amplifier output, the Rebec RPX-B680 combines six channels of Class AB amplification with DSP processing and flexible connectivity to provide a practical platform for entry-level active car audio systems.

Compared with the RPX-B480, its main advantage is the addition of two amplifier channels, allowing more flexible active speaker configurations while retaining the integrated and compact approach of the RPX-B Series.

Rebec RPX-B680

Six-channel Class AB amplification with flexible DSP processing for 2-way and 3-way active car audio system configurations.