Fully Discrete NFCA for Superior Sound – The A90 Discrete features 4 NFCA-Discrete modules with 39 transistors each, ensuring high output, strong current, and low impedance for effortless headphone driving.

2 Gain Settings for Versatile Use – Low gain minimizes noise for IEMs, while high gain delivers ample power for full-sized headphones, ensuring broad compatibility.

Ground Loop Noise Terminator – Use the GND/LIFT switch to eliminate ground loop noise. Set to GND by default, switch to LIFT if noise occurs for uninterrupted audio.

Headphone Amp & Preamp in One – Functions as both, with 20Ω SE and 40Ω balanced output impedance, ensuring compatibility with various power amps.

Expanded Inputs with Ext90 – The A90 Discrete has XLR and RCA inputs but expands to 4 XLR and 2 RCA with the Ext90, plus a 12V Trigger for easy device sync.

Precision R2R Volume Control – Uses relay and resistor networks for precise, durable volume control, ensuring accurate channel balance and remote convenience.

Volume Memory for Convenience – Remembers volume settings for PRE, HPA, and PRE+HPA modes, restoring previous levels automatically for seamless use.