heeeelp please audio reserch 5SE - resistor blew up

Contact ARC and send them a picture, they will you what you next move should be. If they identify the resistor, they may (a) tell you the probable cause or (b) give you the right part number and send the correct OEM resistor. Question: did you purchase the 6550 from them. 

DALE CW-7 27Kohm 5% 7watts

http://4.bp.blogspot.com/-JAWy0XG8FDg/T-cXlMfi9gI/AAAAAAAAGm0/T_IG1xFSijY/s1600/P1050346.JPG

https://paragonsns2.imgix.net/wp-content/uploads/2016/05/arc-ref6_circuitboard.jpg?w=1024&h=1024

ARC is very responsive

get a new tech IF they quote you ten hours

the NOS Tung Sol 6550 is a killer tube in the 5 se.......Andy at Vintage Tube can help you w that and test that 6550 for you....do NOT reinstall it before testing..

Its not the big 27kOhm that blew. It’s the 1k grid resistor to the 6550 pass element. OP sent a pic to me.

"New old stock" 6550. Members with no tube testers at home are at a HUGE disadvantage. Yes! Test before install is always a good idea but OP may not have access to a tube guy. Using NOS tubes in regulators is one of the dumbest ideas I know.