The A331A from Schrödinger Audio is a High Performance,Portable Vacuum Tube Headphones Amplifier, is a bridge to enhance sound quality between the portable music device such as Smartphone and Headphones.

  To know more about this product please visit: 
  http://www.schrodinger.hk/index.php/product/61

  Schrödinger Audio is OEM & ODM Manufacturer for Portable Vacuum Tube Amplifiers. 

Specifications

• Tube: Raytheon JAN6418 Mini Tubes x 2            
• Frequency Response：10-33KHz            
• Signal to Noise Ratio：120dB            
• Output power : 250mW(32Ω)            
• Total Harmonic Distortion：＜0.004%    
• Battery: 3.7V, 1100mAh rechargeable Lithium Battery
• Battery Charging Time: Around 3hrs
• Battery Working Hour: 10hrs (Max)         
• ​​Charging Port: Micro USB, 5V            
• Input Port: 3.5mm Stereo Jack            
• Output Port: 6.35mm Stereo Jack            
• Headphone Impedance: Suitable for 8-300Ω Headphones
• ​Colour : Black (Other Color orders are also welcome)  
• Dimensions : 110×70×20mm            
• Net Weight: 0.2kg