In need of new tubes for Marshall JCM 2000

M

Mindys87

Member
Hey,

I'm looking to change tubes in my Marshall. I have jj el34's right now, but I feel that I want tighter and bigger low end. I have interest in 6CA7, KT77 and Tung sol tubes. Playing metal, mostly thrash, but I like full balanced sound. I was reading that 6CA7 and tung sol has a little more American 6l6 take on el34's, it's really tempting to try something like that in my Marshall. Any advices comparing those 3 I mentioned? Thanks.
 
Many here will disagree, but I don't find power or preamp tubes to make that big a difference. Differences...sure, but tubes aren't gonna make your Marshall into a tight focused thrash machine IMHO. An EQ pedal, boost, and pickups will have a FAR greater effect. That said, JJ E34L are supposed to have a more headroom and a bigger/tighter low end. I've tried KT77, and =C= in my Wizards and prefer the stock JJ E34L for the subtle differences. Any difference between tubes can easily be negated with the amps eq. really.
 
MetalHeadMike said:
Many here will disagree, but I don't find power or preamp tubes to make that big a difference. Differences...sure, but tubes aren't gonna make your Marshall into a tight focused thrash machine IMHO. An EQ pedal, boost, and pickups will have a FAR greater effect. That said, JJ E34L are supposed to have a more headroom and a bigger/tighter low end. I've tried KT77, and =C= in my Wizards and prefer the stock JJ E34L for the subtle differences.
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I'm sure that it's not going to change sound drastically, but i don't need much. I like how it sounds and if i can add a little on top of what i like, why not to try. As i was reading 6CA7 would probably have biggest impact on the sound. Maybe i will change power amp tubes and will leave preamp as it is.
 
Mindys87 said:
I'm sure that it's not going to change sound drastically, but i don't need much. I like how it sounds and if i can add a little on top of what i like, why not to try. As i was reading 6CA7 would probably have biggest impact on the sound. Maybe i will change power amp tubes and will leave preamp as it is.
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Most guys feel preamp tubes will have a more dramatic impact on tone FWIW. The subtle nuances are there, but to me it's not significant. I'm sure certain amps respond with a more noticeable effect, but of the 35 or so amps I've tube swapped on, only 1 amp had truly significant effect and it was the preamp tubes that made that difference. That was a JJ Jr. and it was night/day where the stock preamp tubes sounded great and swapping in anything else made the amp extremely dark and muddy in the low end.
 
MetalHeadMike said:
Most guys feel preamp tubes will have a more dramatic impact on tone FWIW. The subtle nuances are there, but to me it's not significant. I'm sure certain amps respond with a more noticeable effect, but of the 35 or so amps I've tube swapped on, only 1 amp had truly significant effect and it was the preamp tubes that made that difference. That was a JJ Jr. and it was night/day where the stock preamp tubes sounded great and swapping in anything else made the amp extremely dark and muddy in the low end.
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I guess you never know until you try by yourself :D . Like with every amp or pedal. It will.not sound the same as on YouTube.
 
Metal head mike and me are of the same opinion. I know other talk about vintage amps having more of an effect. I can't speak to that. the one thing that i do is use silver dragon 12ax7 preamps to get rid of some of the background noise from the preamp
 
Try an EVH lll 50 watt head, and then put your Marshall mod on the back burner.

It's not always a good idea to try to make your coffee machine make toast.
 
Honestly preamp tubes change more for me than power tubes. I rarely feel a substantial difference with any tube swap. The subtleties are there.

The few times I have noticed a major difference was when changing from say a 12AX7 to a 12AT7 or changing powtube type.

One MASSIVE difference was dropping NOS GE and JAN into the Rivera K-Tre. It was a totally different animal.

The JJ E34L is a great value tube IMO. Sounds the best of the JJ El based offerings. I am in general not a fan of JJ's. The E34L seems more robust than the JJ EL34 and EL34II. I have a quad of JJ 6CA7 around, but I have not tried it yet. But I hear good things in general.
 
Here's a cool read about 6CA7 and 6L6 in Marshalls.
https://www.marshallforum.com/threads/swapping-el34s-with-6l6s.95449/
My preference in my Marshall's are true beam forming element 6ca7's and 6550's. Both tube types are more of linear frequency response, I've tried to love EL34's over the years and I just prefer the 6L6 qualities that 6ca7 and 6550's bring to the table.

The EH6ca7 is a beam forming element tube like a 6L6 so they are close to an actual GE/Sylvania 6ca7 you are going to find in new production.

I ran EH6ca7's in my 69 plexi and they sounded great when compared to my Sylvania 6ca7 loaded 68 plexi.

That being said alot of great tones can be had with EL34's, it just depends on what your ears like.
 
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Mindys87 said:
Hey,

I'm looking to change tubes in my Marshall. I have jj el34's right now, but I feel that I want tighter and bigger low end. I have interest in 6CA7, KT77 and Tung sol tubes. Playing metal, mostly thrash, but I like full balanced sound. I was reading that 6CA7 and tung sol has a little more American 6l6 take on el34's, it's really tempting to try something like that in my Marshall. Any advices comparing those 3 I mentioned? Thanks.
Click to expand...
KT77.
 
I threw some 6CA7s in my JCM2000 DSL50 two weeks ago and couldn't get the bias right. I wasn't gonna bother with new resistors, so I threw the EL34s back in. I threw the 6CA7s into my Origin 50C and they biased right up and sound killer. Plain old ValveArts or JJs are just fine for the DSLs. Get a decent NOS 12AX7 for V1 and V2, but that's all you need.
 
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