DIY Class A 6J5 Vacuum Tube Preamp Preamplifier Hi-Fi Headphone Amplifier Kit

DIY Class A 6J5 Vacuum Tube Preamp Preamplifier HIFI Headphone Amplifier Kit -2021. 
 
Specification: 
1. 16 HZ-28.5KHZ; 
2. Headphone Impedance: 16-600ohm; 
3. SNR:> 108db; 
4. Channel separation <-100db; 
5. Distortion: <0.003% (distortion noise but not all, of the second harmonic modified sound); 
6. Input and output: standard 3.5mm headphone jack; 
7. NE5532 op-amp; 
8. Tube:6J5 or 6J3; 
9. Power requirements:±12-15V DC power supply 10W above transformer; filament require 12V more than 2A; 
10. Size: (L)10cm * (W)6.3cm; 
 
Note:  
This DIY Kit need to be soldered by yourself. 
The photo shows assembled product, just for your reference. 
 
Package included: 
1 x Headphone Amplifier DIY Kit.