#1
I bought a 2nd hand marshall head but the tone has gone pretty fuzzy almost like a big muff pedal, when i use the ultra channel. Is this a common sign of needing to change valves?. What else tells you when you have to change em?
#3
marshall jcm9000 50w. what valves are best?..EHX, Mesa Boogie, Marshall. Do they differ at all?
#5
yeah, they all have different characteristics. It's preference though, just like what amp you choose. Some are also just tested and re-branded from another maker, like Mesa's tubes. When the powertubes are going, the amp starts to sound lifeless and dull, maybe some loss in volume. Preamp tubes usually give you wierd noises or microphonic problems, but they generally last a lot longer than power tubes. You can also tell sometimes by looking at them. The powertubes should all have a nice healthy orange glow, sometimes there can be blue, but it's not necessarily a problem. A pinkish purple cloudy hue "can" sometimes be an airleak in a tube, whereas the flourescent blue is usually a harmless contaminent. Nothing is set in stone though. If the amp was used when you got it, it's usually a good idea to replace the tubes since you don't know how old they are. New tubes can breathe new life into an old amp, it did for mine. On average, with average playing time, powertubes last about 1-2 years before degrading the sound, whereas preamp tubes usually last twice as long.

There is a tube thread sticky at the top of the page if you want to ask those guys specifics.
"The fool doth think he is wise, but the wiseman knows himself to be a fool." - W.S.
amp clips
amp vids
#6
Quote by kmf1
marshall jcm9000 50w. what valves are best?..EHX, Mesa Boogie, Marshall. Do they differ at all?


That's cool, I've never played a JCM9000. How do they sound?
#7
Quote by Gutch220
That's cool, I've never played a JCM9000. How do they sound?

it's like a JCM900, but 10x the wattage. it's insane stuff. doesn't break up until a few hundred decibels.
Quote by corduroyEW
Cheap amps are "that bad". They suck up your tone like cocaine at Kate Moss' party.


I am Michael!
#8
A few hundred decibels???? 200 decibels causes death from sound which is the same as about 300 pounds of tnt going off next to you. Thats loud
#9
you mean you can't handle 200 dB's? Everyone knows JCM9000's are at least 225 dB's when cranked. Get with the program junior, and try one out
#10
Quote by Gutch220
you mean you can't handle 200 dB's? Everyone knows JCM9000's are at least 225 dB's when cranked. Get with the program junior, and try one out

i was using one when i was testing booster pedals. cranked. it was so awesome. like...woah.
Quote by corduroyEW
Cheap amps are "that bad". They suck up your tone like cocaine at Kate Moss' party.


I am Michael!