CelAudio

X86 based digital player

At present, almost all the global leader streamer adopt the X86 architecture. However, there are some inherent difficulties in using the X86 architecture to design HiFi systems. There are five major design difficulties in the X6 streamer.

Excessive power consumption: The X86 architecture, especially the high-performance X86, has a huge power consumption. And the high power consumption directly leads to difficulties in power supply design. The low-power X86 platform, like ATOM, the performance is also low. it loses the advantages of low latency and high performance, making it difficult to meet the requirements of some applications such as Roon Server. While the NUC is balanced in performance and power consumption, But the NUC is a single-channel 12 - 19V power supply, and the entire board is powered by on board switch power supply, which has problem of I/O interference compared to the ATX architecture. At the same time, the PCIE of the NUC is not enough to meet the design requirements of the high-end HiFi system playback.

Heat dissipation: High-performance X86 hosts generate much more heat than ARM platforms and ATOM platform. This increase in circuit thermal noise impact sound quality so much. Due to reasons of vibration and circuit noise, the HiFi system cannot adopt an active heat dissipation system. Therefore, How to design a highly efficient passive heat dissipation system is a factor that must be taken into account.

Huge CPU current requirement and dynamic voltage regulation demand: The high-performance X86 CPU requires a lot current and dynamic voltage adjustment. This leads to the power supply of the CPU and RAM must be realized by a switching power supply. How minimize the swtich noise is a problem that must be solved.

PCIE installation structure: In the standard X86 chassis, the PCIE card is vertically installed and is fixed only by a screw. This installation method is very unfavorable for the shock absorption design, and the shock absorption treatment is one of the key to get High end sound.

Too many peripheral hardware have an adverse effect on the sound quality: For example, The PWM (Pulse - Width Modulation) for adjusting the fan speed will generate a lot of noise, which will affect the sound quality. In X86 design, the sound quality is affected by a lot of peripheral hardware.

CelHeart-G1 Music Motherboard

After two years of dedicated preliminary R&D, CelAudio finally launched the CelHeart-G1 music motherboard. Through a streamlined design, this motherboard only retains the hardware related to audio playback and must exist system maintenance, such as the HDMI. The BIOS optimized for the audio system, the reasonable PCIE installation structure for shock absorption, and the passive heat dissipation design make the CelHeart-G1 the core hardware of CelAudio's new generation of music servers.

Indispensable High-performance CPU And I/O Linear Power Supply

The main advantages of the X86 platform are as follows:

Low latency and high performance: The forwarding delay of a high-performance CPU with independent PCIE bus is very low, and low latency is a key in the quality of digital audio playback. The lower the latency, the better sound quality. At the same time, only a high-performance CPU can meet the requirements of applications such as Roon Server.

Discrete southbridge chip or I/O die: Compared to the High-performance ARM architecture, the high-performance X86 platform has a southbridge chip or I/O die for I/Os, thereby separating computing and I/O processing. It can be separately powered. As well as, the high-performance X86 platform can provide a large number of PCIE buses, which can design the elements that have a decisive impact on the sound, such as storage, network, USB, etc., through PCIE, thereby providing independent high-quality power supply and clock, etc. This can improve the sound quality very much.

In summary, the advantage of the X86 platform lies in the low latency resulting from the high performance of the core. On one hand, it can achieve excellent sound playback quality due to the low latency. On the other hand, it can meet the application needs of Roon and others that have high CPU performance requirements. Meanwhile, at the hardware level, the South Bridge chip or I/O die can adopt a separate linear power supply design. Therefore, when designing high-quality Hi-Fi products using the X86 platform, it is essential to simultaneously support a high-performance CPUand a linearly powered I/O system.

Revolutionary Dual-Stage ATX Power Supply Architecture

Traditional HiFi designs employ standard motherboards. Although the onboard switching-mode power supplies inherently exhibit high noise levels, implementing external linear power supplies for 12V/5V/3.3V ATX power delivery can still substantially improve sound quality. CelAudio further advances noise reduction through innovative engineering: maintaining three independent linear power rails (12V/5.9V/3.9V) for external power supply, while implementing secondary linear regulation, ATX power sequencing control, and voltage conditioning directly on the motherboard. This comprehensive approach significantly elevates audio reproduction quality

CPU And I/O System Of Motherboard Have Separate Power Supplies And Are Mutually Isolated

For the CPU and memory of the motherboard itself require dynamic voltage regulation, linear power supplies cannot be used. So, switch mode power supplies are still used to supply the CPU and memory. For the most critical I/O part, it is supplied by the on-board linear power supply of the CelHeart-G1. The I/O circuits, such as PCIE/SATA/USB/Network/USB/NVME, all use linear power supply. And the onboard isolation between the CPU/memory 12V and the I/O 5V/3.3V is provided, This reduce the overall I/O interference to a very low level. Thus, it provides outstanding soud details and frequency bandwidth.

The motherboard Structure Specially Designed For Passive Heat Dissipation

The demand for passive heat dissipation was fully considered in the CelHeart-G1's design phase. On an X86 high-performance motherboard, the heat mainly come from the CPU and NVME. The CPU and NVME are layout on same side of the motherboard, and can use one group heat pip. thereby simplifying the design and achieving efficient heat dissipation. This design extremely suppresses thermal noise and guarantees the sound quality.

Reasonable PCIE Interface Planning

The CelHeart-G1 music motherboard is designed with four PCIE X1 interfaces, which fully meet the PCIE expansion requirements under various installation conditions. It can be used in various designs such as music servers, routers, and simple Roon core machines. At the same time, a shielded and impedance matching FPC is designed to connect the CelHeart-G1 and other application cards for minimize the interference and PCIE signal transmission loss.

Installation

Shock absorption, passive heat dissipation and esay upgrade are fully well designed.

"Voiceprint" Tuning Methodology Of CelHeart-G1

Since the CelHeart motherboard itself is the platform hardware for many different devices, like music servers, routers and NAS. CelAudio make its sound characteristics neutral. Nevertheless, the CelHeart-G1 still uses a large number of film capacitors to improve the vividness and dynamic range.

The locking torque of the power cord can flexibly adjust the sound characteristics. Since the end of 2022 CelAudio use brass tin-plated serrated screw crimp connectors to connect all internal DC power bettween boards By manually adjust locking torque of the internal DC cable, we can ensur the universal applicability of the CelHeart-G1 in all product forms.