The Ayon HA-3 is a tremendous tour de force in single ended headphone amp design.  Recently reviewed by HiFiKnights found in the new number 1 choice among their excellent references which include Bakoon, Trilogy, and Questyle.  We found it has exceptional decay and all the glory of the 45 tube.  It's here as a trade in from a client who had it only for a short time.  He's decided to go for the 3 X's more costly Trafomatic Primavera.  This Ayon, in like new condition and with tubes that have less than 100 hours on them, is a fantastic amplifier for anyone who wants top reference sound at a very reduced cost.  Warning, if you have not heard a great 45 tube, be weary, it will spoil most things out there for you in the future.
http://hifiknights.com/recenzje/ayon-audio-ha-3-wzmacniacz-sluchawkowy/

Specifications

Tube Headphone amp

Ayon HA-3

Class of Operation

Pure Class A, SE-Triode

Tube Complement 

2 x AA45 Mesh, 2 x 12AU7

S/N Ratio

> 100dB (unweighted)

Input Impedance

50 kΩ

Frequency Response at 32Ω

15 Hz - 35kHz 

Harmonic Distortion (at 150mV )

< 0.01%

Channel Separation L/R

> 89dB

Output Power at 32Ω

500mV 

Output Impedance - Headphone

16Ω – 600Ω

Line Input

RCA phono sockets

Headphone output

¼” Stereo Jack (6.35mm)

Power Consumption

~ 65W

Dimensions Main Unit (WxDxH) cm

22x30x20 cm

Dimension Power Supply (WxDxH) cm

22x30x10 cm