True music is emotion. Meticulously adjust the tones that TI supported
The E7PCM1792A is a portable audio player that embodies the emotional beauty of TI sound, featuring a standard configuration of a dedicated E7 module equipped with dual TI PCM1792A DACs. The PCM1792A, originally designed for high-voltage desktop use to achieve an extremely high dynamic range, required optimization for portable housing. To achieve this, LE OS and the newly developed AsymPower Control integrate and manage all aspects of the DAC, analog stage, and power supply. By rigorously fine-tuning circuit voltage, signal path, and I/V conversion operating conditions from the ground up, we have managed to extract a "core softness and sweet lingering resonance"—qualities unattainable through spec-driven approaches that rely solely on theoretical values—within the constraints of a portable device. By meticulously reproducing every detail from the initial attack of the sound to the last trace of reverberation, it delivers an unprecedented and moving musical experience.
LP tuning based on emotional reproduction, going beyond the measured values of the PCM1792A's characteristics
Instead of theoretically optimizing the output voltage, we deliberately adjusted the load balance and transistor bias points on the signal path, utilizing slight non-linear components to shape the harmonic structure and transient characteristics. To achieve the "soft sound" and "blending mids and highs" unique to the PCM1792A, we searched for the optimal balance between power supply voltage suitable for portable devices and sound quality, further improving upon a prototype that achieved a dynamic range of 125dB with ±5.8V for the I/V stage and 5.2Vrms output. Our uncompromisingly redesigned power architecture achieved both a dynamic range of 123dB and 4.7Vrms output, realizing musical richness and supple texture. It delivers a meltingly beautiful sound that resonates with listeners, harmonizing not only with harmonically rich vocals and acoustic instruments but also with modern sampled effects.
The sweet sound of music played on classic instruments of the past proves that theoretical optimal solutions are not always the best.
The E7PCM1792A prioritizes musical coherence—such as melodic continuity, harmonic sustain, and spatial depth—over peak measured values. The sound produced by the PCM1792A, alongside numerous stationary masterpieces, exists in a realm distinct from numerical measurements. It delivers rich midrange and high frequencies, a subtle elasticity in the low end, and a smooth, lingering resonance that permeates the entire soundstage. This is the result of electrical harmony created by a design that has pushed linear characteristics to their limits and the precision of the analog stage's power supply. The change from 125dB to 123dB is a deliberate adjustment made to achieve the optimal listening experience after reaching theoretical performance. Without compromising the E7 series' consistent pursuit of musical reproduction accuracy, its sweet sound harmonizes the comfort of analog with digital precision.
Precise control by AsymPower Control supports the emotional beauty of sound.
By individually optimizing the ± current response of each circuit block and precisely controlling the operating current and time response, the subtle offset of transistor operating points and the matching of power supply impedance organize the harmonic composition, bringing out the PCM1792A's inherently soft yet solid sound. While typical symmetrical power supply configurations prioritize theoretical values and power consumption efficiency in simulations, AsymPower Control overcomes the technical challenges unique to asymmetrical power supply configurations. It minimizes heat generation, voltage drops, and minute signal loss that can easily occur in high-voltage DACs, while maximizing the chip's potential capabilities, achieving a high level of both stability and efficiency as a portable device.
A clean operating system focused on sound quality
The E7 series uses a newly developed in-house operating system, "LE OS," specifically designed for audio playback, as existing operating systems cannot suppress fundamental negative effects on sound quality. By focusing on its origin, audio playback, and eliminating unnecessary elements as a music playback device, a powerful MCU delivers exceptional performance during music playback. Its lightweight design, optimized for audio, minimizes digital processing noise and ensures silent tranquility, naturally reproducing everything from the start of a song to its lingering reverberations.
High quality comparable to balanced connection, even with single-ended output.
While general DAPs tend to have circuit structures where single-ended output performance is modest, this module fully utilizes all output channels of both PCM1792A chips, with all circuits such as IV conversion, LPF, volume control, and buffer amplifiers operating at full capacity. Even with the 3.5mm single-ended terminal, it achieves uncompromising playback in terms of information, localization, and dynamics.
The devil is in the details: a PCBA-specific modular replacement mechanism.
A modular design with the largest exchange area in industry history, promising adherence to high ideals. By eliminating the headphone amplifier from the configuration and removing parts like jacks that bottleneck sound quality and performance, we achieved an optimized layout and wiring in a vast space. Numerous independent power supply circuits are arranged in the DAC analog section to thoroughly reduce noise. The mirrored surface engraved with "PCM1792A" is beautiful and brings joy of ownership.
Lineout selection functionality. EA4-focused mode also added.
Users can select line-out from multiple voltage outputs. Building on the experience of the well-received limited edition "P6Pro10th Limited," a dedicated line-out optimized for the EA4 amplifier has been adopted. By switching between the regular LO and this dedicated line-out, the E7 and EA4 can be combined to achieve a high-dimensional balance of rich sound, delicate nuances, and precise sound imaging.
