300T blown fuse

[Hop]

Anyone have ideas why my 300T would blow a fuse to the middle par of tubes?  I run it with a vintage 215s cab loaded with 2 x 15" K140 JBL speakers - usually master on 3 and ch#1 volume at 3- 4 as well.  The led indicator usually registers green - at times a pinkish/red when I lay into a low E/B.  Fuses are registered at 100Mm.  When I picked the amp up used a year and a half ago it also had blown fuses - 2 of them.  At the time my tech replaced them as he said the ones in the unit where not to-spec.  Tubes registered fine back then.  I always use a surge supressor too.  Are blown fuses something to be expected with this beast?

Hop

[RichBriere]

HOP.........I've never heard of that as a characteristic of the amp. Mine has never had any problem.  :^>)  Sure that your speaker cable is good?

RB

[Hop]

Hello Rich - yeah, my speaker cable is Monster Cable that I paid through the ass for.  Its never shown any signs of a problem.  Can you or others think of any other reasons/problems that I would cause the amp to blow fuses?

[Brandon]

Periodically, especially after alot of heavy use, my head will blow the occasional fuse.  I've had my head for almost three years and this has happened twice in that time (in different fuse positions).  My head seems to function great and I just carry some spares (which are actually hard to come by!).

If you find out that this is indicative of a real problem, please pass the info along!

Brandon

[Hop]

Brandon - thanks for the reply.  I have had my 300T almost 2 years and use it 3-4 times a month.  Blown a fuse once in this time period.  At some gigs the other band's bass players beg to use it, so in a sense I have nights where its getting double duty. It would make me rest better if there really is no "alarm" that I have blown a fuse in this time frame.  And I agree, the fuses never seem to be readily available...

Hop

[hop]

you have to remove the back grill panel (4 screws).  The fuses insert into the top of the chassis  - 3 of them - one per each pair of tubes.

[Anonymous]

If the power tube LED's go ANYTHING but green with correct power up you have a problem.  Make sure the standby switch on the front panel is "down" before you turn on the juice at the rear panel switch.  Since you no doubt have a spare set of tubes, you might try them.  The biasing contacts on the rear panel are great!  NEVER turn on a 300T unless the front-panel standby switch is in the "standby" position.  You can verify the continuity of your speaker cables with an ohm meter, of course.

[Rocketboy]

I'll make it a point to identify a source for the output fuses.