Need help with guitar amp

[BLACK-13]

guys....i got a marshall valve jtm 30 amp..... everytime i play it only can last about 15mins before it dies off.....i got feelin its the tube...its blown i guess....so can anyone enligthen me where to get the tube or repair the amp tks......

 

[keysersoze808]

guys....i got a marshall valve jtm 30 amp..... everytime i play it only can last about 15mins before it dies off.....i got feelin its the tube...its blown i guess....so can anyone enligthen me where to get the tube or repair the amp tks......

hi
doest it sound like 'farting' before dies off? if that your tube already gone, must be replace with new .
if the volume drop while u playing, u off and on it again ,still can use it ,may be bias too hot ,check if your tube turn red, i mean the whole tube plate turns red..

 

[BLACK-13]

yup.....something like that......any ideas where to get tubes?....thks for the reply...really appreciate it...

 

[keysersoze808]

yup.....something like that......any ideas where to get tubes?....thks for the reply...really appreciate it...

using 5881 power tubes. in Sg i have no idea but
http://www.octave-electronics.com/audio/tubes/index.shtml

would have it. mail them for quote/ shipping. for preamp tubes
(12ax7) i think u can easily get in SG . if dont , u can buy from the same store/or ceriatone -they do shipment worldwide and their price kick ass

but my suggest u replace power tubes first and see if working or not.last time i repair laney LC15 -10 years old with original factory tubes. after checking found that only power tubes need to replace, preamp is still fine.
power tubes get more stress/hot then preamp.

btw how long u r using the amp, hours per day?

 

[BLACK-13]

hmm.....the amp was given to me....so i tried playing it the very first time and this happen... then i just left it there about 2yrs...now i wanna relived it i guess....heheeheh

okok...i'll take noted from ur advice....and update....thks once again