Price is for well assembled board.        without TUBE
(there is no instruction, part list , need DIY electronic basic. there is risk of failure if you do not know how the tube amp work.)
 
 
 

PCB size 370mmx130mm


Features:
referenced /based and upgraded from famouse A NK Au dio N ote Kit One 300B, which circuit is stable and sound perfect.
Pre-amplification and promoting using 6SN7 and 5687 (or 12BH7), alternative install mode

Filament with adjustable regulated output current up to 3A, can use 2A3 when filament voltage is 2.5V

Description:
300B tube is a directly heated triode, when the screen voltage of 350V (pole on the screen between the cathode voltage),the control gate voltage at negative 74V (eg in terms of B + voltage is 350V + 74V + 10V voltage cathode resistor cattle output voltage drop = about 434V),can output 8W Class A power. 300B tube is the title "Dream King of tube"!

Classic A N K Audio Note Kit One 300B dual-channel tube amp is a very good 300B tube amp, its powerful driving ability and magic tone leave a deep impression for everyone.

 

 

 

Using PCB circuit board to build tube amp is more simple, convenient, faster, easier . easy to adjust and better anti-interference ability, as long as connected to the input and output power transformer, then you can make a high-quality tube amp by yourself. Highly recommend for DIY hifier

 

 

 

 
 
 
Note on transformer: Complete transformers is the most important to get best working condition for this board.
power transformer should be high power high permeability core.
Core size should be no less than EI 105 x 60mm, the primary input 0V-220V-235V, shield grounding between primary and secondary , the secondary output high voltage 400V-0-400V 0.2A or more.
one group 5V 3A for 5U4G rectifier filament ,two groups 7.5V 2.5A for 300B filament(because using full-bridge rectifier, the regulator to 5V for 300B filament use, so two sets of windings must be independent),
one group 6.3V-V0 -6.3V 2A for 5687 filament (the V0 is used to raise the filament voltage taps, and other windings must be isolated, this is one of way to make smaller noise of tube amp)
one group 3.15V-0V-3.15V 2A for 6SN7 filament (the 0V tap grounded, also help make smaller noise of tube amp)
 
 
 
 
 
Holes drawing:
 
 
 
Schematic for reference:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
>>>>>>Reference only:      the price here not include any tubes
 
assembled with 12BH7 tube with regular small tube socekt, for your reference only: the price is not include tube
 
 
 
 
 
 
>>>>assembled with 5687 tube with CMC gold plated socekt for your reference only: the price is not include tube, if you also will install 5687, need to pay more US$ for the CMC socket