problems on tube/valve questions on VOX night train

[Kimmi]

hi everyone,

i would like to ask those who have knowledge or experience tube amp problems where do you buy ur tubes.

so far names i've heard are martin elec,burlington and sim lim.

however, i'm new to tubes and afraid of making a wrong purchase.

My vox NT has ran into some problems.i played it for a while and suddenly the sounds cut off and crakling sound occurs immediately afterwards,this crackling/no sound is accompanied by a oddly bright reddish glow appearing in one of the four tubes on my NT. the tube is position at the back of amp.

its still under warranty but i would like to learn how i can deal with this after the warranty runs out because it is alittle troublesome to run back to CM everytime this occurs.i have to learn how to fix this if the problem is as minor as faulty tubes.

my doubts are:
probable reasons to this problem?
where is the best to purchase tubes ?( subjective question )
things i have to take note off ?
how do i change the tubes on the NT?

cheers everyone!!
happy holidays!!

 

[Direngrey]

http://www.dougstubes.com/

 

[fenderrules]

..Alright,

So I assume these problems still occur even when you have sent it for servicing at CM? How many times have you sent it for repair?

IMO, it won't be wise to actually DIY on the tubes unless you have any prior experience. Would advise you to actually email VOX about it and describe your problems.

What you can also do is to head down to CityMusic with your NT and do an A B test with the NT at the showroom. Just ask and the staff there will tend to you as well as the main technician. Usually they will exchange a new set for you if it's still in that state and still under warranty.

As for the probable causes, just wanna ask, is the Pentode-Triode mode switch in it's Standby position whenever you power it on or turn it off? Leaving it on either mode will sorta shorten the tubes life and complications can happen, such as loss of tone.

Cheers and Merry Christmas!

 

[Kimmi]

fenderrules:

hi,

yea,i've sent it back once a few months back,turned out it was just the tube problems.now that it happened again, i'm guessing its the same problem.not too sure though.

yea,the glow from this one particular tube was abnormally bright compared to the rest.

for the question would be, whenever i on the amp,i make sure it is in its stand by mode, then let it warm up 2mins before switching to either pentode,triode. when i off it, i make sure i put it back to stand by then off the amp.

basically,i'll make sure it is at stand by when i off or on the amp.

probably giving it a try tomorrow,hope cm is open since its boxing day.

 

[lightice]

sounds like one tube is red plating.

Too much voltage going into that tube. Send it in for servicing.