#1
Hey as I mentioned before I just recently purchased the combo JCM 900 Dual Reverb. To me it sounds a little tad bit brittle and i was wondering if changing the 5881 tubes in it to EL34's would help the sound out at all. Does anyone here know how that would change the sound of the amp? Thanks
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Quote by BrianApocalypse
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#3
They are 5881's - your amp must have been made before they switched over to the 5881's.
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Quote by BrianApocalypse
Good call

Man, you should be a mod, you know everything.

#4
if its brittle, its def 5881s in there!

they give better cleans, but terrible crunch in marshalls, swap for the EL's and re-bias it

the mk3's come with el's as standard which is good and generally have better sound than dual reverbs anyway

change the 5881s (6L6s) now!
#5
Ok that's what I was hoping, because it just sounded really dry, and didn't have that saturated sound. Is there anything else I can do to help out the tone - or anyone else want to chime in?
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Quote by BrianApocalypse
Good call

Man, you should be a mod, you know everything.

#7
5881 = trash
Quote by deg0ey
The best pickups for emo are no pickups at all...


Gear:

1996 Les Paul Classic w/ Alnico II's
Marshall Jubilee 2550
Avatar 2x12..V30 and G12H
Vox V847 Wah
Assorted pedals
#8
I guess I should PM Andy and see if he still has the 5881's in his amp, since he has the two speaker version of my amp.
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Quote by BrianApocalypse
Good call

Man, you should be a mod, you know everything.

#9
Could it just be the tubes or is it possibly the whole diode clipping circuit that is giving off those harsh(er) tones? Does anyone know anything about the circuit? Or is it just most likely the tubes?
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Quote by BrianApocalypse
Good call

Man, you should be a mod, you know everything.

#10
it's probably a combination of the tubes and your EQ. try a darker tube such as a JJ. But use EL34's and not 6L6's
#11
Ok thanks. Yeah I have been emailing Bob at Eurotubes all day long, and I am probably going to order a set of JJ E34L's. Does anyone know how those compare to the standard JJ EL34's?
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Quote by BrianApocalypse
Good call

Man, you should be a mod, you know everything.

#15
Yeah I am probably getting ECC83S for pre-amp tubes. Is that what you use Gutch? He seemed to think it would sound best in my amp
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Quote by BrianApocalypse
Good call

Man, you should be a mod, you know everything.

#17
Unless you play your amp with the volume on 8 or above all the time, then dont really worry about the Powertubes as much as the Preamp tubes. ECC83S' are fab in this amp. I have em in both my 4502 and 4100. I DO have EL34's (Groovetubes) in the combo and JJ 6L6's in the 4100 head. The 6L6's are a little nicer and round out the bottom end in the 900's. I love em. The EL34's are that classic Marshall crunch and great gain, but only really noticeable when the volume is wayyy up and the power amp is being worked out.
Good choice either way, but you wont really be able to tell until you crank it...and that is really loud in either the 50 or 100 watt versions.