Cayin HA-2A Tube Headphone Amplifier 

Thanks very much.

您好，HA-3A是Auto Biased.

Sorry to inform you that the HA-2A uses NOS vintage tubes, which don't have modern equivalents currently in production. However, NOS tubes are renowned for their reliable quality, exceptional sound, and rarity. In fact, these are already the best tubes for the HA-2A to make it sounds great!

In our Tube Headphone Amplifier line of products we also have HA-3A, HA-6A and HA-300MK2.

no, but will sound great and 'enough'

well yes highend for most ears

是的，HA-2A此次我们使用的都是NOS古董管。