Copper, as an alloy with tin, nickel, or zinc, is used as a raw material for wind instruments, which form the central part of an orchestra. These wind instruments transmit deep and heavy sounds through tubes of copper alloys.
Sound with a sense of depth Sound with a sense of weight Sound with a greater balance
In addition, copper is the second most electrically conductive1 metal after silver. With superior electrical conductivity and shielding performance than typical metals, the AK380 Copper is able to deliver a different sound signature than the existing duralumin-based AK380.
* The copper used in the AK380 Copper boasts a 99.9% pure elemental property.
Electrical conductivity of metals
10 ~ 20
24.6 ~ 34.5
5 ~ 7
9.58 ~ 13.3
13 ~ 18
AK380 Copper is finished in a two-step process using a 5-axis milling machine, and approximately four hours of processing time is required per unit.
Due to the highly-ductile nature of copper, the shavings tend to curl inwards rather than out when creating thread lines, causing the ends of milling tools to become damaged or broken. Because of this finicky nature of copper, the material requires more hands-on labor by an operator compared to other materials such as aluminum.
Uncoated raw copper quickly oxidizes from exposure to outside elements, which makes mass production very difficult to manage.
Fully processed copper is approximately 3.2 times greater in metal weight when compared to duralumin
While a 530-gram block of raw material is milled to create the 55-gram frame of a duralumin-based AK380, a 1.7-kilogram block of copper is processed to create the 175-gram frame of an AK380 Copper.
Comparison between processed Copper and Duralumin
After two stages of milling, the finishing process begins to smooth the surface of the product and create a hairline-brushed finish.
The finishing process requires 30 minutes to an hour for a skilled worker.
* A process in which the surface of an object is polished into its final form.
To prevent oxidation, the AK380 Copper requires more time and effort in the final coating process than any other Astell&Kern series product.
To maintain the raw, natural feel of copper, numerous tests were conducted using a variety of antioxidant materials. As a result, we were able to hone in on the optimum processing time for each stage of the coating process.
Anti-oxidation coating is completed in a four-stage process. Skilled workers continually monitor the processing time at each stage of coating.
[Stage 1 – Degreasing] In the degreasing stage, oil and other debris that occurred during processing and finishing are removed electrically.
[Stage 2 – Etching] In the etching stage, an oxide film is applied to the exterior surfaces to highlight certain areas that were marked via processing, finishing, and laser marking.
[Stage 3 – Film Application] Upon discovering that the look and feel of copper is largely dependent on the film application, we invested a large amount of time testing various applications.
[Stage 4 – Drying] The surfaces of the frame is dried after the film application, and each unit is immediately packaged and sent to the assembly process.
Wrapping the AK380 Copper in Natural Leather
The leather case for the AK380 Copper is made of a natural type of leather known as V1, which is produced in Turkey and used by many leading luxury brands.
The V1 is generally used in the making of handles, wallet interiors, and accessories, representing the highest quality in natural leather. It’s most famously used for the handles of Louis Vuitton bags. Unlike other brands that apply a coating on the surface of the leather, the case for the AK380 Copper is not finished with a surface coating in a rather difficult production process to truly capture the unique personality and characteristics of the user.
The AK380 Copper's leather case maintains the same color for the first six months of use and tans gradually depending on the use, care, and style of the user. Generally, the color in the vegetable tanning of leather is determined by the additive. The chestnut component used in the AK380 Copper's V1 leather case results in a caramel color.
The V1 Story
The V1 is produced by the Sepiciler Caybasi tannery in Turkey.
The Sepici tannery was founded in 1930 before the leather industry had yet taken shape in Turkey. The company started with leather caps and uppers of lambskin shoes and eventually grew into a successful company in the Yesildere region, being renamed to the Sepici and Sons Collective Company.
The history of the Sepici tannery is intertwined with the founding of the Republic of Turkey and later became incorporated, evolving along with the country's industrialization. The company celebrated its heyday in the 1970s under the name Sepici Caybasi Leather Ind., Inc.
The company soon grew into the largest of its kind in Turkey and was selected as the best tannery for 10 consecutive years since 2003. It is now one of the most successful tanneries in the global leather market.
Evolved to Serve Pro-Audio
Astell&Kern has stayed on the course, offering the truest and most natural sound possible. In order to become a device that professionals want, Astell & Kern decided to make a bold move and restart all processes from the beginning. The new AK380 Copper offers the most authentic sound from any digital music format with enhanced features that are sought-after by Pro-Audio.
32bit 384kHz Bit to Bit Playback
Native DSD (up to 5.6 MHz) Playback
Parametric EQ with 20-band 0.1dB
200 Femto Second VCXO Reference Clock
DNLA-based AK Connect App
Metal Touch Sensor Home Button
Every bit of the AK380 Copper was designed for Pro-Audio in mind. The sound that Pro-Audio people have been looking for starts with the AK380 Copper.
32-bit 384kHz bit-to-bit Playback
The circuit design of the AK380 Copper including the DAC can handle 32-bit music natively & is ready for all 32-bit processing. Bring it on! Other products have traditionally used sample rate converter (SRC) method down sampling for playback, but the AK380 Copper is capable of playing back 32-bit, 384 kHz original sound without any down sampling.
As a result, the AK380 Copper plays up to 32-bit, 384 kHz, all 24-bit music files, or double layer DSD 5.6MHz natively, without conversion or compression.
PEQ (Parametric EQ)
A parametric equalizer (PEQ*1) was added to the AK380 Copper to deliver detailed adjustment of the original sound, and an audio digital signal processor (DSP) was added to aid in this process.
This frees up CPU cycles previously needed for calculating graphic equalizers (GEQ), allowing more detailed and accurate calculations via the dedicated DSP.
The audio DSP expands the existing 10-band, ±0.5 dB graphic equalizer (GEQ*2) to 20-band, ±0.1 dB to more precisely adjust the frequency and gain (dB) as well as more accurately specifying the frequency range via Q value adjustments.
* The PEQ supports up to 8 kHz - 192 kHz (8/16/24-bit) formats, but DSD and 32-bit audio are not supported.
The AK380 Copper's PEQ Playback Using Audio DSP
The other Products GEQ Playback Using Audio DSP
AK380 Copper 20-band PEQ and AK240 10-band GEQ Frequency Values
What is Parametric Equalization (PEQ*1)?
Parametric equalization refers to the ability to increase or decrease the volume within the Q value range. A Q value is a frequency range relative to a selected frequency.
The frequency range decreases when the Q value increases and vice versa.
What is Graphic Equalization (GEQ*2)?
Graphic equalization divides the audible frequency register into several registers and increases or decreases the level of each register with a volume slider to adjust the respective frequency's characteristics. The switches of the volume slider are connected like a graph to visually determine the frequency characteristics, hence the name "graphic equalizer."
Equipped With a Femto Clock to Deliver True Original Sound
Astell&Kern implemented a voltage-controlled crystal oscillator (VCXO) high-precision clock with a reference jitter value of 200 femto seconds*3.
Femto clocks are commonly used in high-end audio systems, and the clock is measured in high-precision femtosecond units (one quadrillionth of a second).
What is VCXO?
A VCXO, or a voltage-controlled crystal oscillator, is a type of crystal oscillation device that creates oscillation frequencies. External environmental stimuli, which in this case mean voltage inputs, influence the frequency value. Adjustments to the voltage input tunes a precise frequency value.
What is Jitter?
Jitter refers to the undesired deviation in time that occurs in a periodic signal. In this case, jitter is the error that occurs in the reference clock required to perform the sampling in digital audio equipment.
By utilizing a femto clock, the AK380 Copper is able to create a more accurate frequency value and make fine jitter corrections. As a result, the AK380 Copper faithfully reproduces analog sound closer than ever to the original source when transmitting a digital signal as an analog signal.
AK Connect App
Astell&Kern has further enhanced DLNA functionality via the AK Connect app. Wireless networking DLNA (version 1.0) connects to a NAS or PC, and is easily controlled with a smartphone or tablet through AK Connect.
Source files on a PC or NAS can be freely transferred and streamed without the hassle of turning on the computer and physically connecting with a cable.
If on the same access point (AP) network, music files on a PC or NAS can be played back via DLNA.
DMP (Digital Media Player)
Finds a list of content on a media server for selection and playback.
DMC (Digital Media Controller)
Finds a list of content on a media server and establishes a connection to a playback-capable device (renderer). By default, a DMC establishes a connection between a media server and media renderer and controls content playback-related operations.
DMS (Digital Media Server = Network Server)
Actually stores the media content to be shared. When connected to a network, the DMS transmits/distributes the media content for other devices to stream or download.
DMR (Digital Media Renderer = Network Player)
Connects to a media server via media controller for content playback.
Pressure-sensitive Metal Capacitive Touch
The AK380 Copper is the first Astell&Kern product to utilize a metal capacitive touch interface. The pressure-sensitive Metal Touch home button responds to fine pressure changes so users operate the device with just a light touch on the metallic pad.
The light and the object are the main theme of the AK380 Copper design. Any shadow of an object portraits the exact shape from the perspective of the light at that moment. The way of reproducing the true sound of music from digital formats is quite similar. Nothing more or nothing less. The design motif of the AK380 reflects our philosophy of music and sound.
The AK380’s design was inspired by “light” and “shadow”.
While the design of the AK240 captured as a moment in time of light and shadow, the AK380 Copper is designed to express the change of time with more angles on its body. You will notice the different angles of surface design as you view the AK380.
We believe that the beauty of the design shall reflect what the AK380 Copper can do with music. As different angles of light casts different shadows, different music will give you a variety of emotions.
- Model : AK380 / AK380 Copper
- Body Color : AK380 : Meteoric Titan, Black / AK380 Copper : Copper
- Body Material : AK380 : Aircraft Grade Duralumin / AK380 Copper : Copper