>>>>VACUUM TUBE  PRECISE FILAMENT VOLTAGE REGULATOR USING THE SAME TRANSFORMER,NOW YOU CAN DESIGN BUILD YOUR S.E. OR PUSH PULL AND YOU CAN ROLL YOUR OTHER OUTPUT TUBES.
******EXAMPLE,,,,A TRANNY WITH AN OUTPUT VOLTAGE OF 12 VAC CAN BE REGULATED AT ANY FILAMENT VOLTAGE FROM 2.5VAC TO 12VAC.PICTURE SHOWS TUBES LIKE 2A3,300B,811-10 etc. WITH ADJUSTED FILAMENT VOLTS.2000 WATTS MAXIMUM POWER,ITEM MEASURES 1 1/4 X 1 7/8 X 1 1/16 SURFACE CHASSIS MOUNT.SCREW IN CONNECTIONS, 2 INPUT & 2 OUTPUT.
>>>>>TRANSFORMER SUGGESTION; YOU CAN USE ANTEKINC  TOROIDAL TRANSFORMER MODELS WITH DUAL FILAMENT OUTPUT.
 1) AS-1212,,Ebay item# 372195246427
 2) AS-0509,,Ebay item# 253108637967
>>>>Also you can use this item to make your own VARIAC (Schematic is available for paid buyers only).
*****QUESTIONS ARE ALWAYS WELCOME AND PLEASE CHECK MY OTHER COOL AUDIO STUFF.