Details：

New and improved version, adding filament suspension circuit, better circuit performance, overall improvement of signal-to-noise ratio and tube's life. PCB Size:220mm x 133mm Tube Model : 2PC 12AU7 Works volage: AC1---High voltage：0-AC280V (0.1A) AC2---filament：0-AC9V (2.5A) AC3-- delay：0-AC8V (0.5A) Suitable transforemr ：https://www.ebay.co.uk/itm/275738282860

Note：

Diy Kit:all parts need buyer to solder it ,(not included tubes) Assembled Board:have tested it well ,(not included tubes)