The Astell & Kern AK T5p (1st Generation) 

is a premium, closed-back audiophile headphone launched in 2015 as a special-edition collaboration with German audio giant Beyerdynamic. It modifies the baseline Beyerdynamic T5p (Gen 1) specifically to maximize performance when paired directly with Astell & Kern high-resolution digital audio players (DAPs). 

Key Technical Specifications

• Driver Type: 45mm dynamic drivers angled slightly forward to mimic speaker-like presentation.
• Technology: Beyerdynamic Tesla Technology (high magnetic flux density for increased efficiency).
• Impedance: 32 Ohms (highly optimized for low-power mobile use and DAPs).
• Frequency Range: 5 Hz – 50,000 Hz.
• Sound Pressure Level: 102 dB. 

Core Differences From the Standard Beyerdynamic T5p (Gen 1)

• Hardwired Balanced Cable: The primary difference is its hardwired, non-detachable cable terminated with a 2.5mm 4-pole balanced plug natively compatible with Astell & Kern hardware. It includes a short 2.5mm-to-3.5mm adapter for standard phones or laptops. [1]
• Enhanced Tuning: It features an adjusted sound curve that pushes slightly harder, tighter mid-bass slam compared to the standard, analytical, and slightly lean stock Beyerdynamic tuning.
• Cosmetic Branding: The earcups feature an embossed metallic "A" logo, though the headband retains the Beyerdynamic badge.

Sound Profile and Performance

• The "Open" Closed-Back: Celebrated in audiophile communities like Head-Fi for producing an incredibly spacious soundstage with an airy high-frequency extension that mimics an open-back design.
• Detail Retrieval: Delivers precise instrument separation, highly revealing analytical treble, and textured mid-bass response.
• Isolation: Features high physical noise isolation with genuine leather ear padding and memory foam inserts.