The real JP2C

So a few years ago I called mesa just to talk about power tubes. I was thinking about swapping the power tubes in my V and I wanted to see if the wonderful people at mesa could give me some info. I really wanted to know if anybody at mesa rolled tubes. I don't remember who I talked to but of course he said everybody there uses 440's for their V's. I was just feeling him out but he said it very convincingly. We then talked a bit about how the V was designed specifically with the 440's in mind. Just like the mark II was designed around the 415's, the V was designed around the 440's. I even heard somewhere else that mesa even tweaked the V to get some of that 415 sound that the 440's just can't do. So I wondered; what's the power tube the JP2C was designed around? Obviously it's a new amp, and mesa uses 440's for all thier new amps, but the JP2C is different, it's supposed to be a reissue. So if mesa is true to thier word, (I'm naive and belive everything they say) then the JP2C would be better suited with the 415's in the power section. So I got my hands on a quad of these babies, the Sylvainia STR 415 6l6. :mrgreen: New old stock even! And I thought I'd share my opinion.

I'd always heard amazing things regarding the 415's. This is my first time experiencing them and they definitely live up to the hype. I almost crapped my pants when I fired up the JP with these babies in there. Holy **** they're good. Noticeably better, right away. Slightly louder, a lot crisper, tighter bottom end(my palm mutes might be showing up on a Richter scale somewhere), a high end that has pleasantly crisp sparkle, a touch sensitivity that still has my jaw on the floor, and a clarity that makes the organic sounding JP sound even more organic. If you own a JP2C, it's hungry for the 415's. The 440's sound week in comparison. They sound loose and fizzy. I can't go back to them. Even the feel is different. The 440's feel loose, where the 415's feel tighter. The 415's just feel right. They respond so well to the nuances, it's remarkable. As I was breaking these bad boys in I could help but think about mrsmitty and the reasons he didn't get along with his JP. I wish he could give these a shot. Such a difference. I might still be high but I was thinking about the tweak mesa did to the V to give some more of the 415 flavor. And the differences we discussed between the V and the JP in mrsmittys honeymoon thread can almost be summed up with these tubes. I mean that the V is tighter, brighter, and less scooped. Besides the bottom end, I'm my opinion, mesa gave the V some of these qualities to make up for the inadequate tubes. And I also think they didn't do a great job of it, if what I'm talking about has any truth to it. I say that because that nasty midrange character the V has... well that might be in part to the tube tone chasing. I was playing the JP with the 415's and I thought; this is what the V was chasing, or trying to copy, these beautiful tubes, but it couldn't quite get there. Or maybe I'm completly wrong and the V just has its own thing. But these tubes somehow remind me of the V, so the whole tweak thing popped in my head. Anyway, mrsmitty, I think these tubes were the answer to your JP2C woes. I think the JP2C, just like the mark II, is suited for the 415's. And before someone says; of course the 415's are going to sound better and they're better suited for any amp, well, that's why I mentioned mrsmitty, all the things he thought were lacking in his JP2C are made up for with these tubes. They fit the JP2C like a glove, it's a match made in heaven. :mrgreen:

Cool!

Yeah, tubes make a difference for sure. I don't mind the 440's. I like them better than the 430 that my Mark IV originally came with and I remember really liking the 420's back in the 90's. I've never tried the 415, but I hear about the sylvania tubes all the time and would sure like to try some.

But I sure don't like the JJ preamp tubes. Makes Mesa amps muddy, congested, bassy and dark. My newish Triaxis came stock with the JJ's and it was mud city. Tried a few EHX and some chinese and it sounded so much better. Same story with the Mark V, changed to Russian 2 (EHX) and again a big improvement. The JP2C sounds great and I'm really happy with it, but I can't wait to try some other preamp tubes in that one.

I never had a problem with the 440's before. I thought they were just fine too. But now I'm ruined. The difference is almost comparable to using el34's (447) and using 440's in my V. Not in tone, but it's just that noticeable. Now I might have to explore preamp tubes. A road I thought I wouldn't go down.

I just switched the preamp tubes in my amp and there was an unbelievable difference! I know some people say if it isn't broke don't fix it, you couldn't be more wrong.

If I still had the JP2C, I'd consider trying those tubes Samuel suggested. When I was posting the "honeymoon..." thread, someone actually mentioned trying different tubes. But I've never been a tube roller kind of guy, and then there's the Mesa warranty I didn't want to have issues if something happened while experimenting with tubes.
Anyway, that's good if the 415's are making a difference for you.

I replaced three of the preamp tubes in my JP today just to see if it made a big difference in this amp as well. And, yup. It did. Just like I have experienced in the past, I don't like JJ preamp tubes in Mesa amps. The blanket came off and the amp just sounds more balanced and articulate with more definition in the mids. I only used some tubes I had laying around. I used two Mesa Russian 2 (electroharmonix) and one Engl labelled tube that is either a Sovtek or some kind of Chinese tube. I replaced v1-v3. I'm definetly ordering some new preamps for the JP soon. I will keep the 440's for now, but sure would like to try the Sylvainias.

MrSmitty, it's too bad that you gave up on the amp. I really think a simple preamp tube change might have made the difference for you.

I've just put a set of Groove Tubes Sylvanias in my IIC+.

There's no going back, and any thought of using my blue stripe MkIIIs instead has fallen by the way side 'til I try them all with the exact same tubes.

I have several quads to swap around, but no time when I can wind them all up to the requisite volume where I am this week. When I do, I'll try preamp tubes too, time permitting.

When I've got it clear in my head where all this tube lore leads, I'll go out on my own JP2C discovery trip.

Bullen said:

MrSmitty, it's too bad that you gave up on the amp. I really think a simple preamp tube change might have made the difference for you.

Click to expand...

I did try a different preamp tube in V1, but it made no difference. That's ok though, I'm not too sad about the JP2C not working out for me. I've realized how much I like having: 3 different channels, master output and solo boost feature (like my MkV and Dual Rec).

I got one with these STR 6l6 430's 8)

I had a set of Mesa 6L6 454s that were in my Mark III when I bought it, tried it in that amp & my JP compared to new 440s and for whatever reason I though the 440s sounded just a little better. The 454s were a touch more dull, maybe because they're old? Who knows.

I also tried a Tung Sol V1, which has been my go-to V1 tube for lots of other amps, and in the JP it neutered the gain & sounded weak. I was honestly surprised. Put the JJ back in..

I still would like to try a Mullard in the PI. If that fails too, then I don't know WTF!!

I changed all my preamp tubes to new Ruby ac5 HG (chinese shuguang 9th gen) a couple of weeks ago. So far I'm really pleased with the results. The amp sounds really balanced and articulate with these tubes. Very nice warm, focused midrange too. Very nice.

I'm still using the 440's. I think they are fine. But I've been thinking that I might try some old 420's I have laying around. I still have the original 420's that my old 2ch recto came with. I don't think they have that many hours on them as I mainly used Svetlana =c= EL34 in that amp. I always loved the 420 back in the day though. I sure want to try some Sylvanias but they are so expensive.

I have just ordered a quad of Phillips 7581A which are supposed to be the same ore very close to STR415 although I am confused about ver conflicting reports.


This is what Francesco from Mesa Boogie wrote:


"Hi Moritz,

thank you for contacting MESA/Boogie.

Unfortunately, STR 415 are long since sold out! I remember Mike or Doug mentioning that STR 415 was the actual designation for Sylvania 6L6 tubes (35W) - that makes them very similar to 7581As. 387s are rated for 30W. In all honesty, the difference between the two should be negligible and I believe they would both sound great.
This said, given the fixed bias nature of our amps, our recommended tube of choice for the JP-2C is the 6L6GC STR 443 (MESA/Boogie part number 750650D)."


What does this mean?

Is it save to run STR415 or 7581A in the a JP without bias adjustment?


Is the Sylvania STR 415 now a Phillips 7581A? I know the 7581A is military grade and 35W rated. But is the STR415 also?

I have also ordered 3 Tungsram and 4 RTF ECC83 Tubes 8) I am very exited for a NOS retuning as well. Lets see if it all holds up.

Once this ist done I'll probably be too afraid to play the JP-2C on a regular basis as its too precious LOL. Then I need tu buy a second one ^^