How many power tube must be active on 10W?Is MK V in short?

[tofisi]

When Im running amp on 10w I noticed that the three power tube(from left to 5UGB) are active in all three chanell.Is this normal? I was read in manual that must be active only a two (from left to 5UGB). When I run 45w are active two inner and with 90w are active all. That should be OK.

Today when I was switched standby to on I was looking the power tubes I heard a big pop and I saw a short flesh on thrd power tube(from left to 5UGB). I was thinking to a bad power tube but than I was swap inner tubes with outside I saw again the flash at the third position. Is something wrong with my amp or some short on this socket? My friend told me that it can be a bad capacitor. Because capacitor needs a few hours to empty.I will try tomorrow with a new power tubes to see is if I still get a flash on third position. Now the amp is warm and I hear three pups when I switch standby to on. When I switch standby to off I hear a big pup and also I hear a big pup when I switch 10w to 45w.
I have to say that I had four months ago rectifier tube in a short with blowing fuse and last week is gone preamp tube on V1.
I ask for your opinion and advice.

 

[tofisi]

When Im running amp on 10w I noticed that the three power tube(from left to 5UGB) are active in all three chanell.Is this normal? I was read in manual that must be active only a two (from left to 5UGB). When I run 45w are active two inner and with 90w are active all. That should be OK.

Is someone so kind to look behind his amp to see how many power tube are active on 10 watt mode.
Please.

 

[SteveO]

I'm pretty sure it's two- one inner and one outer. Just checked the manual, and it is indeed two. "One for power, and one to balance the transformer".

 

[tofisi]

I'm pretty sure it's two- one inner and one outer. Just checked the manual, and it is indeed two. "One for power, and one to balance the transformer".

Is this means that is something wrong with my amp?? Because when I run on 10 watt I have active three power tube - two inner and one outer.

 

[mejoshee]

I'm pretty sure it's two- one inner and one outer. Just checked the manual, and it is indeed two. "One for power, and one to balance the transformer".

Is this means that is something wrong with my amp?? Because when I run on 10 watt I have active three power tube - two inner and one outer.

don't count 5u4gb as a "power tube." it rectifies power, but doesn't amplify. in 10w mode, there will be 2 power tubes--1 inner, 1 outer. the rectifier tube also has to be on.

i don't know how you are using your amp to have screwed up so many tubes, but at this point i would take it in because who knows if you also screwed up other things besides the tubes. is it still blowing fuses?

 

[phyrexia]

Including the 5U4GB, the three tubes closest to the power cord are active in 10w mode.

 

[tofisi]

don't count 5u4gb as a "power tube." it rectifies power, but doesn't amplify. in 10w mode, there will be 2 power tubes--1 inner, 1 outer. the rectifier tube also has to be on.

I don´t count rectifier tube. I was told that are active two inner and one outer power tube(three power tubes on 10 watt mode).

i don't know how you are using your amp to have screwed up so many tubes, but at this point i would take it in because who knows if you also screwed up other things besides the tubes. is it still blowing fuses?

I was not screw anything with my amp.I suspect bad shipping or screwed from vendor,now I suspect another two bad power tube. The fuse is now OK.V1 has gone when I was took it from the socket and set it back for chek a contact. Because sometimes amp has produce a big noise and crackle.

 

[tofisi]

Is that a problem with some other bad preamp or rectifier tube( I have all new power tube) or you think that the amp has internal error??

please anyone