Single Rectifier Problem

[chelch]

Hello all. I will try to make this as simple as possible. My rectifier is blowing fuses like crazy. Actually I think the power tubes fail and then the fuse blows. This only happens when i am using the head at band practice at loud volumes. I play at home for hours at moderate volume without any problems. Here is an example.

I had a set of non mesa tubes in the rec. AFter playing for I would say 20 min my head just died. Put in another fuse and flip switch from standby to power. I then hear a pop from the cab, then a humming, and then the head shuts off again and the fuse is blown. I then swithed in my mesa tubes and played for another hour without any problems and then head died again and same problem. Every fuse I put in it blows and head dies.

Seems to me that the power tubes are failing and then that causes a surge of power which blows the fuse. Any help would be appreciated. Im pretty stressed out about this. Thanks guys.

 

[ibanez4life SZ!]

Take it to a tech to get it checked out....doesn't sound like a tube problem as you have swapped them. Something inside must be malfunctioning, causing it to blow.

Have you tried a completely knew set of tubes....it would be a long shot, but maybe both sets of tubes you have are defective.

 

[chelch]

I first had the 6l6 tubes in and the fuse blew. Replaced fuse and turned on and fuse blew right away without even playing. Seems like at that point the tubes was toast.

I then replaced with the factory mesa tubes and not much later after playing at a loud volume the fuse blew again. Replaced fuse and it blew as soon as I went from standby to on. So now I suspect the mesa tubes are toast.

I dont have another set of tubes so I cant troubleshoot any further on it. I find it wierd that I can play at home at a moderate volume with no problems but when I give the amp juice it seems like it cant handle it. Is it possible the preamp tubes are bad as opposed to the tubes that are visible in the back of the head?

 

[jbird]

Are you using the correct replacement fuses?

 

[chelch]

yea..im using the 2 1/2 amp 250 volt slow blow.

 

[chelch]

Hi guys. What i did was I turned the on switch to on and left standby switch in standby position and only one the the two tubes are glowing. I assume I am blowing fuses one of the tubes fail. Didnt think to check this on the other tubes I already tossed in the garbage. Looks like im heading to the reapair shop tomorrow to find out why I am blowing these tubes.

 

[chelch]

Sorry about the multiple posts. Spoke with Mesa and he stated issue could be a bad ''screen resistor'' whatever that is. I stated to the Tech that tubes only blowing at hig volume. Low volume no problem at all.