CelAudio | CelHeart-G1 HiFi Motherboard

High Power Consumption

High-performance x86 systems consume substantial power and present major difficulties in power design. Low-power x86 models, by contrast, sacrifice low latency and high performance. While NUC units feature relatively lower power draw, they adopt a single 12–19V power input and come with densely packed onboard switching power supplies. Compared with the ATX architecture, NUC delivers inferior I/O power quality and suffers from severe crosstalk. Additionally, its PCIe implementation fails to meet the design requirements of high-end HiFi playback systems.

High Heat Dissipation

High-performance x86 generates significant heat, increasing thermal noise in the circuit. This undermines operational stability while thermal noise itself degrades playback quality. Addressing vibration and acoustic noise caused by excess heat via active cooling is a challenge all HiFi equipment must confront. Balancing thermal management with high performance is a fundamental difficulty that x86-based players must resolve.

Dynamic Voltage Regulation

High-performance x86 CPUs draw large operating current and feature dynamically adjusted voltages managed by the system. This makes switching power supplies mandatory for CPU power rails. Neither the power design of NUC nor the discrete 12V CPU power scheme in ATX architecture can effectively prevent crosstalk generated by onboard CPU switching power supplies from affecting the I/O subsystem. Even when standard motherboards are used for HiFi development, high-grade external linear power supplies cannot eliminate interference stemming from the numerous onboard switching circuits. The power quality of Ethernet, storage, USB and other I/O interfaces is undoubtedly critical to the audio performance of digital audio players.

Vibration Isolation

On standard x86 motherboards, PCIe slots adopt vertical mounting, secured solely by a single screw and a retaining bracket. This configuration is highly unfavorable for vibration damping design, an indispensable consideration in the development of high-end HiFi equipment.

Peripheral Hardware Interference

Standard motherboards rely on fans for reliable heat dissipation. Accordingly, the PWM (Pulse Width Modulation) fan speed control system for the CPU cooling fan operates continuously and generates noticeable noise, which impairs audio playback quality. In addition, components such as temperature sensors and onboard audio chips also degrade sound performance. Meanwhile, certain BIOS settings can also exert a marked impact on audio reproduction.

The Solution

CelHeart-G1 HiFi Motherboard

Following two years of intensive research and development, CelAudio launched the CelHeart-G1 HiFi Motherboard. This motherboard adopts a revolutionary dual-stage ATX power supply architecture with a streamlined design, retaining only hardware essential to audio playback and system maintenance.

Through a BIOS optimized for audio performance, carefully planned PCIe interfaces, and a passive cooling design, the CelHeart-G1 forms the core hardware platform for CelAudio's new generation of music servers.

Seven Optimization Directions

High-Performance CPU & I/O Linear Power Two-Stage ATX Power Design CPU & I/O Separate Power Isolation Passive Cooling Design PCIE Interface Planning Vibration Isolation Mounting Sonic Signature Tuning

Core Design

Indispensable High-Performance CPU and I/O Linear Power

The principal advantages of X86-based network players are:

Low Latency at Hardware and Software Levels, with Broad Application Support: A high-performance CPU paired with PCIe bus architecture delivers exceptionally low forwarding latency — a critical factor in digital playback quality. Only high-performance processors can meet the demands of applications such as Roon Server.
Discrete Southbridge and PCIe Power Supply: High-performance X86 platforms feature independently powered southbridge chips, separating computing from I/O processing. The abundant PCIe lanes enable effective isolation of storage, network, USB, and other subsystems into independent designs.

Therefore, when designing high-quality HiFi products on the X86 platform, simultaneously supporting a high-performance CPU and linear-powered I/O system is indispensable.

Power Architecture

Revolutionary Two-Stage ATX Power Design

Traditional HiFi designs employ standard motherboards. Despite the high noise from the motherboard's own switching power supplies, using external linear 12V/5V/3.3V ATX power can still substantially improve sound quality.

CelAudio takes noise reduction further: the external power supply employs three independent linear regulators at 12V/5.9V/3.9V, while the motherboard implements secondary linear processing, ATX power-on sequence management, and precision voltage adjustment — significantly elevating sound quality.

Isolation Design

Motherboard CPU and I/O System Separate Power and Mutual Isolation

The motherboard's CPU and memory require dynamic voltage regulation and cannot use linear power supplies, so switching regulators remain necessary for these subsystems. The most critical I/O section, however, is supplied by dedicated on-board linear power supplies.

PCIe, SATA, USB, Ethernet, NVMe, and all other I/O circuits employ linear power supplies. Isolation is provided between the CPU/memory 12V rail and the I/O system's 5V/3.3V rails, reducing overall interference to negligible levels — thereby delivering exceptional detail, bandwidth, and sonic fluidity.

Thermal Design

Motherboard Structure Specially Designed for Passive Cooling

In the CelHeart design process, passive cooling requirements were paramount. On a high-performance X86 motherboard, the primary heat sources are the CPU and NVMe drives.

CelHeart adopts a coaxial CPU and NVMe layout, simplifying passive cooling design while achieving efficient heat dissipation. This configuration effectively suppresses thermal noise, safeguarding playback quality.

PCIE Interface

Reasonable PCIE Interface Planning

The CelHeart-G1 HiFi Motherboard features four PCIe x1 interfaces, fully meeting expansion requirements under various installation conditions and enabling multiple product configurations.

Suitable for music servers, routers, dedicated Roon core machines, and other designs. Additionally, impedance-matched shielded flexible circuit boards are specially designed for FPC-type PCIe interfaces, enabling lossless connection between CelHeart and companion boards.

Vibration Isolation

Adequate Heat Dissipation and Vibration Isolation Mounting Considerations

In terms of vibration isolation, the CelHeart's PCIe-based design delivers excellent isolation performance — whether deployed in NS6 or NSX music servers, or in future router and Roon core machine designs.

Effective vibration isolation treatment optimizes sonic performance and is an essential consideration in high-end HiFi equipment design.

Sound Tuning

CelHeart "Sonic Signature" Tuning

Since the CelHeart motherboard is platform hardware that can be deployed in various final form factors, excessive sonic coloration cannot be imposed. Component selection is therefore approached with exceptional care.

No conventional audio capacitors are used; instead, large quantities of artifact-free SMD film capacitors are employed to enhance sonic liveliness and micro-dynamic performance.

Power cable locking torque can subtly adjust the sonic direction. All power connectors use brass-tin-plated serrated screw crimp connectors, individually calibrated by hand with precision Tohnichi torque screwdrivers — effectively balancing sonic relaxation and liveliness.

Five X86 Design Challenges