Made by 2nd Staff Corporation Navigator Headphone Amplifier HPA-900. This unit is a headphone amplifier designed to accurately drive the SONY CD900ST for reference purposes. It features a very honest sound, with a focus on recording/mixing environments. When using the CD900ST, - Adequate volume - Information in the mid-range - Ease of understanding the sound positioning are very clear, allowing for confident use as a monitor. Although it is designed specifically for the CD900ST, it has enough power for other headphones and can be used as a high-quality headphone amplifier with few quirks. It also provides a balanced sound for listening purposes. ⸻ Functions and Specifications - Input: Stereo (L/R) / Aux1 / Aux2 - Output: General / CD900ST - Aireal / Real switching switch - Independent volume control - Made in Japan ⸻ Condition - Minor scratches and scuffs due to use on the exterior (see photos) - No malfunctions that affect actual use *Please refrain from purchasing if you are sensitive to the appearance, as this is used equipment. ⸻ Accessories - Main unit - AC adapter (DC24V) *Everything shown in the photos is included. ⸻ Notes - Returns and refunds are not accepted after purchase to prevent swapping. - Operation has been confirmed, but any problems during shipping will be handled by the shipping company. - Please purchase only if you understand used audio equipment. - Model: HPA-900 - Output terminals: CD900ST - Controls: Master volume, Aux1, Aux2 - Accessories: AC adapter