When Every Note Is In The Right Place

C.O.S. ENGINEERING

COS Engineering, founded by three close friends serious about audio entertainment, is dedicated to developing high end, Hi-Fi gear of the digital era that renders music listening a sheer natural pleasure.

Debut in 2014.

Meet C.O.S

from Taiwan, the Engineering Team that delivers Quality and Value

The Evolution of Excellence

NEW D10 V4 "SE"

We are proud to announce the D10V4SE, a Special Edition.

refinement of our flagship D10.

By re-engineering the power foundation and signal isolation,

we have achieved a new benchmark in transparency and

musicality. Read on >>> for more

Network Switches

S10 and S6

Pleasurable music can be brought back by controlling noise in streaming, as S10 has demonstrated. Here comes S6, a streamlined version of S10, making HiFi-quality streaming readily accessible.

To Assist the S6 users enjoy even more as funds permit meet Audiophile‐Grade Architecture the new LPSI.

COS LPS1 is an Ultra‐Low Noise Dual‐Channel HiFi Linear Power Supply and features two independent outputs, meticulously optimized to handle the distinct demands of your digital ecosystem:

Output #1 (12V, 1A): Specifically tuned for high‐performance HiFi Ethernet switches, such as the COS S6.

Output #2 (12V, 2A): Provides robust, low‐impedance power for high‐ demand Ethernet routers and streaming bridge devices. Read on >>> for more

User Installable Upgrade Cards

MC/MM Phono and Streamer

STREAMING (optional)

Stable and quality streaming is available, with or without a wire, for TiDAL, Spotify, Deezer, and Qobuz. Setup is easy with iOS and Android applications.

PHONO-AMPLIFIER (optional)

There are 5 loading resistors and 3 loading capacitors, all selectable, to accommodate phono cartridges of your choice. Other features include JFET input stage, on-board low-noise linear regulator, and handpicked components for RIAA curve matching and zero capacitor between audio signal paths. Extremely low in noise and distortion.

Read on >>> for more

Sometimes Simplicity is the answer ?

New S10

Audiophile-grade COS's first audiophile-grade switch

Low noise power Toroid power transformer

Low noise power
Toroid power transformer
Low noise filtered AC inlet
100~120Vac or 220~240Vac
Bulk smoothing capacitors (4,700uF X 12)
4 low noise regulators

Network status LEDs on/off control switch
Copper ports control switch :
each port can be individually enabled or disabled

Low jitter (0.025ps) oscillators X 2

Specifications
AC Line Voltage 100~120Vac or 220~240Vac settable
SFP Ports X 2, 1000/100Mbps auto-negotiated
Copper Ports X 8, 1000/100/10Mbps auto-negotiated
Each copper port can be individually enabled/disable
Oscillator jitter 0.025 ps
Power consumption 10 VA
Dimension 260 mm (W) X 250 mm (D) X 60 mm (H)
Weight 3.6 Kg (package not included)
Color Silver or Black

D10- V4 The New D10-V4 SE Shipping APRIL 2026 >>>> READ MORE

D10 is a dream component for your beloved sonic pleasure. It is a DAC, a pre-amp, and a headphone amp, well built with streaming capability. Yes, the same spacious, supple and dynamically powerful sound that COS products have been offering. D10 is also a phono amp, one that delivers from your preferred vinyls luscious vibes.

Built with the utmost care and patience to deliver this stunning DAC, it shares that perfectly sculptured design as the other family members.

COS ALGORITHM, BUFFER and RE-CLOCKING

COS's proprietary algorithm with a linear-phase delay FIR filter can up-sample original data to 176.4K or 192K. D10 stores digital data in a one-second buffer before converting to analog signals, under the coordination of a crystal oscillator with a jitter precision less than 1ps and a dedicated re-clocking circuitry.

NEW D-10-V4"SE" Even Better Again " we used to say a High Performance DAC with a Pre-Amp on board, now it has elevated to a High Performance Pre-Amplifier "All In One" with DAC and Options to make this a "sure go to"