Fostex ET-TH4.4BL2Y is an optional balanced Y-cable with a 7N-grade OFC conductor, designed for the TH910, TH919, TH1000RPmk2, and TH1100RPmk2. It terminates in a 4.4 mm TRRRS (5-pole Pentaconn) plug at the amplifier end and two independent 3.5 mm TS plugs at the earcup end — the same dual-connector topology as the stock unbalanced ET-TH2.0UB2Y, implemented here in a fully balanced signal path. The jacket is flexible PVC, the length is 2.0 m, matching the factory cable.
What balanced operation actually delivers with these headphones
The TH910 and TH919 run at 25 Ω; the TH1000RPmk2 and TH1100RPmk2 at 32 Ω — both impedances sit squarely in the operating range of reference-class balanced headphone amplifiers with 4.4 mm Pentaconn outputs, which have become the de facto standard in hi-end portable and desktop DAC/amp units since adoption by Sony, Astell&Kern, and others. A balanced signal path eliminates common-mode noise induced by a shared ground return, which at the impedance levels of these headphones translates to improved channel separation and lower in-band noise floor on high-resolution source material. The two independent 3.5 mm TS plugs at the earcup end ensure each channel has a fully isolated signal path with no shared ground at the split point.7N OFC and signal path consistency
Fostex specifies 7N-grade OFC — 99.99999% purity copper — for both the internal wiring of the TH910/TH919 and the supplied stock cables. Using the same conductor grade in the ET-TH4.4BL2Y keeps the external cable electrically consistent with the internal signal path. At the impedance levels of these headphones, any increase in conductor resistance from impurities is audible as a slight reduction in damping factor. Gold-plated connectors at both ends protect contact surfaces from oxidation under normal studio and listening conditions.KEY FEATURES
- 4.4 mm 5-pole balanced Pentaconn (TRRRS) connector — fully balanced signal path
- Two independent 3.5 mm TS earcup plugs — isolated channel connections, no shared ground at split
- 7N-grade OFC conductor (99.99999% purity) — matched to TH910/TH919 internal wiring spec
- Gold-plated connectors — corrosion resistance and reliable electrical contact
- Flexible PVC jacket — consistent handling in studio and desktop environments
- Compatible with: TH910, TH919, TH1000RPmk2, TH1100RPmk2, TH810, TH818
- Length: 2.0 m
TECHNICAL SPECIFICATIONS
- Model: ET-TH4.4BL2Y
- Type: Balanced, Y-cable
- Source connector: 4.4 mm TRRRS (5-pole Pentaconn), gold-plated
- Headphone connectors: 2x 3.5 mm TS (mono), gold-plated
- Conductor: 7N-grade OFC (99.99999% purity)
- Jacket: Flexible PVC
- Length: 2.0 m
- Compatible models: TH910, TH919, TH1000RPmk2, TH1100RPmk2, TH810, TH818
