#1
I think i just blew my marashall head, its a 89 jcm 800 and i accidently turned it on w/o the cabniet being plugged in. Now my drive channel is quiet and dosent distort, what did i blow and how much to fix it?
#2
Quote by Cledfo0811
I think i just blew my marashall head, its a 89 jcm 800 and i accidently turned it on w/o the cabniet being plugged in. Now my drive channel is quiet and dosent distort, what did i blow and how much to fix it?


Sounds like pre-amp tube, or something around them is fried.. If you are getting sound, then some of the tubes or maybe all are OK, but I'm no specialist...

Did you switch the STAND BY too?
#3
Try the fuses. Then output tubes - those are the closest candidates to be fried by off-load voltages besides the output tranny which isn't so easily replaced.

If you blew the OT - you're in trouble. When you get it replaced, buy a 10W 100Ohm resistor and solder it between the ground speaker tap and, say, 4Ohm tap in a non-breaking fashion (i.e. there is now way to explud it from the circuit). This will prevent the disaster in case you try turning the amp unloaded again.

Cheers.
Last edited by Ace Carson at Sep 13, 2011,