#1
hey all
ive had my marshall half stack for a year and a few months and im thinking its time to change the tubes. as this is my first time, i was wondering if you guys have any recommendations?

also, do i always change the power tubes and preamp tubes together?
how would i know if it was only one or the other?

thanks
Taylor 314CE
Modulus G2T and G3CT
3 Warmoth Guitars
2 Fender MIA Strats--SRV & JM
Alvarez w/ Modulus Neck and EMG DG-20s
Marshall JCM 2000 DSL 50 w/ 1960a cab
Breedlove AC250/SM12
Gold Tone Weissenborn
Adrenalinn III & FCB1010
ALOT of pedals
#2
you dont have to, no.


get a bias tester so you can set the bias correctly
#3
Power tubes wear out lots faster than preamp tubes. You'll go through several output tubes to every preamp tube.
Power tubes - JJ or SED =C=
Preamp tubes - try to find German, Dutch, British, American or Australian tubes. What you are looking for are NOS (new old stock) or very lightly used with good test results (ANOS - almost NOS). Those old preamp tubes will last 20 years or so, so even if it's half worn out it will outlast a new valve.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#4
hey thanks for the feedback

@rickyj - Im not changing them just to change them... i can hear cracking sometime when they are a bit louder and im wondering if thats the tubes. ill definitely look more into a bias tester

@cathbard - Wow thank you for the info
How would i know if it's the power tubes that are worn out vs preamp tubes?
and i thought i read that you should change tubes like once a year, but you're saying up to 20 years?? Did I read wrong?
Taylor 314CE
Modulus G2T and G3CT
3 Warmoth Guitars
2 Fender MIA Strats--SRV & JM
Alvarez w/ Modulus Neck and EMG DG-20s
Marshall JCM 2000 DSL 50 w/ 1960a cab
Breedlove AC250/SM12
Gold Tone Weissenborn
Adrenalinn III & FCB1010
ALOT of pedals
#5
The old preamp valves were heaps better than anything made today. You can often get 20 years or even more out of those old valves. If a modern preamp valve last more than two or three years you're doing well.
It can often be difficult to pick which valve is failing. You should always have spares on hand and if so, determining what is the culprit is easy. You just stick in your spares progressively and see what swaps fixes the problem. Don't wait until you need them before you buy them - ALWAYS have spares.


Edit: Is this for your JCM2000? If so, el cheapo Shuguang power tubes actually sound quite good in those and will save you quite a bit of money which will leave you some spare cash to buy some nice NOS preamp tubes.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
Last edited by Cathbard at May 7, 2011,
#6
Oh wow, there's a lot I need to learn on amp tubes
Do you have a site you recommend?
I read some stuff at the tubestore.com..but I'm the kind of guy that likes to learn things rather than just doing what I read (as I'm sure you know what I mean)

Yeah, I will definitely get some new ones for my JCM2000
I'm thinking they are the power tubes, because I got the amp used from some kid (ebay) a year ago and he said he just changed the preamp tubes..nothing with the power tubes frmo what I recall though. Do the Shuguang power tubes last a good while too? How should I do sizes? I read something about EL34, but I'm not too sure about that stuff
Taylor 314CE
Modulus G2T and G3CT
3 Warmoth Guitars
2 Fender MIA Strats--SRV & JM
Alvarez w/ Modulus Neck and EMG DG-20s
Marshall JCM 2000 DSL 50 w/ 1960a cab
Breedlove AC250/SM12
Gold Tone Weissenborn
Adrenalinn III & FCB1010
ALOT of pedals