Sweetwater is showing "new" mesa tubes

[Nandrewjackson]

Popped up recently in their listings. 6L6 mesa tubes marked "new" and "preorder".

https://www.sweetwater.com/store/detail/MB6L6D--mesa-boogie-6l6-power-tubes-matched-duet

 

[bandit2013]

I saw that too. They are TAD Rebase 6L6GC tubes. Supposed to be closer to the STR415. At least Mesa is looking into other resources due to the conflict with Russia and Ukraine.

https://www.tubeampdoctor.com/en/6l6gcm-str-redbase-tad-premium-selectedI see the pictures of the tubes in the TAD website, base is marked with Germany. That just means the plastic base but where is the actual origin of the tube? I assume they are made in China as like the preferred series made for "thetubestore" in Canada. If they sound good and work, that is all that matters and if there is a good resource and supply chain is not muddied up with conflict mineral issues, works for me.

Before the Redbase line came out, they had a black base but the center keyed index on the tube would easily break off. They were a decent tube. Still have them. They did make some changes following that over the years.
For reference, prior to the Redbase version...
https://www.thetubestore.com/preferred-series-6l6gc

 

[TheRazMeister]

Popped up recently in their listings. 6L6 mesa tubes marked "new" and "preorder".

https://www.sweetwater.com/store/detail/MB6L6D--mesa-boogie-6l6-power-tubes-matched-duet

$100 for 2 tubes? And for the guy who said HIS tubes cost the same....not a realistic viewpoint. I just paid $106 for a set of 4 EL84's that used to cost $40

 

[TheRazMeister]

$100 for 2 tubes? And for the guy who said HIS tubes cost the same....not a realistic viewpoint. I just paid $106 for a set of 4 EL84's that used to cost $40

 

[bandit2013]

I put in a preorder for a quad. The Mesa branded versions. I understand they are made by PSvane. Shuguang is no more to my understanding. Considering prices these days, they are all expensive compared to what was paid yesterday.

 

[Eduardo78]

Yep, they seem the same to me. And always had good experiences with TAD, so I don't see no harm in that. And of course, it has obviously to do with sanctions applied to Russia. Rock on!

 

[Appleridge]

I bought these 448’s from Sweetwater a few months ago. I also have the TAD’s and agree they are identical in appearance. The TADs are a little hotter (not temp but sound). The 448’s seem to fit my mark iv better than the TADs, but both are good. Still wondering why the 448 isn’t on mesa’s website though…

 

[bandit2013]

I am still waiting for them. Nothing yet.

 

[bandit2013]

The STR448 arrived yesterday.
May as well state the target for the tubes: JP2C (2016 but after the Mesa mod to correct the loop issue for the clean channel). Mine was originally equipped with the STR440 (gray code). I was impressed and overjoyed with those power tubes. After a while, I got this random popping noise, more like a static pop you would hear propagating through the power line from something switching on or off. Could not get resolve as it was at random. Did not always happen.

Since I got a new cab just before the tubes arrived, decided to break it in along with the one I have. Plans on getting a Mark VII so I got the cab first. If the VII is available may just order it now.

STR443 (again, gray codes), they were ok, Not as good sounding as the STR440 tubes. No noise or pops so that may have been the fix after all. The only benefit was the STR443 did not make any fizz like the STR440s tend to do. The fizzy fix is to run two 8 ohm cabs to load down the OT at 4 ohms. I sort of lost interest in the JP2C shortly after installing the STR443. I feel the STR443 took away something I desired in the character of the amp and introduced or enhanced the characteristic of the amp itself. The low end was rude, more abundant, loose, such that I had to dial it out and still could not get the desired sound I was getting with the STR440.

Decided to play through the STR443 for a short period last night just to get my thoughts in focus. Then I switched over to the STR440 and played through for a while. Ah, much better. Nice and tight bottom end, almost woody but well defined. Then onto the STR448 for the initial run.

When I ordered them, I did not specify a test code but they came in the gray as well. First impressions: Well damn, it is about time I get to hear the JP2C with something on par with the STR440 tubes.

Mild to heavy gain: Oh yeah! I am getting a bit more complex harmonics from these tubes compared to the STR440. Note that I still am running a 4 ohm load and have not tried a single cab for the 8 ohm fizz test. Top end is similar to the STR440, there is plenty of high frequency content and harmonics just ring out like they did before. Midrange is predictable and quite usable so I can dial in my desired characteristics with one of the GEQs. Low end is almost as dry as the STR440 but with a bit more bloom. I can push up the parametric bass and move the 80Hz slider up without the blah or rude awakening of the bottom end taking dominance like I got with the STR443. I still have the tight attack and palm muting characteristic with the STR448 as I did with the STR440. Not as woody but very close. There is more musical content that is not overwhelming in the low end. I like these tubes more than I expected. I did not have any anticipation how they would sound. Not trying to inflate any hype but they are decent tubes. I will have more opinion after I get some time on them.

Second opinion... 4 ohm (two vert 212s) vs 8 ohm (single vert 212)

STR448 at 4 ohm loading: Nice bottom end, tight, percussive but pleasantly musical. Midrange content is chewy and about the same as the STR440. Top end on high gain is appealing. Light to aggressive gain settings is now enjoyable again. Clean, well it is different than the STR440, still warm but with top end chime and a crisper boldness overall. Sort of reminds me of the Mark V90 clean in the bold setting. Overall, they are so far the best I have had in the JP2C, or are they?

STR448 at 8 ohm loading: Not much different to above except for a few key notes. I did not get the fizzy character as I do with the STR440. Top end and midrange content is about the same. What changes is the low end dominance as it sounds more like the STR440 bottom, a bit bloomy and not as tight as the STR440. I have not run through one of the 412 cabs yet but I suspect I will have similar results. Odd that the JP2C sounds better with more loading on the OT than with the typical 8 ohm load. For running a single vertical 212 cab, I prefer the STR440. Still the STR448 has similar tone pallet but a bit looser on the bottom end running an 8 ohm load. It is like a combination of the STR440 and STR443 in one tube.

Overall, not a bad tube. I have tried a few guitars so far, Charvel pro-mod DK24 with the full shred pickups, mahogany body; EVH Bumble-bee made of bass wood, and Wolfgang pickup which is much darker in tone than the full shred. Messed around in Drop D and then standard E scale. I much prefer the amp and tube combination with the 4 ohm load setup. Base is tighter in response.

Need more time with these to form a hard opinion.

I am working on getting some STR415 and will see how that turns out. I have not used those tubes since 1990 in my Mark III combo.

At least my interest in the JP2C has returned again. Will have to try a mix of tubes, like the STR440 + STR448, STR443+STR440, STR448+STR443. Not sure I am completely sold but for now I am having fun with the change. Note: I have the channel masters at noon. Perhaps I need to push it up some more. I am getting some good air movement and punch from the STR448, but feel I like the STR440 a bit more as I got more authority from them especially when palm muting.

 

[bandit2013]

Before I start sounding like a total nut case on this subject.
I took a closer look at the STR448 and compared it to the STR440. They look identical except for the STR448 has two getter cups vs one. STR440 does not use a coupling bar between the plate studs like the Russian tubes. Plates on the STR440 and 448 look to be the same. Through the oval cutouts on the plates, the beam forming plate also looks to be the same. What I cannot see may be different. One notable difference other than the two getter cups, at the plate seams, there is some additional material in the plates to form additional cooling fins. That is about it.

Almost like comparing a Svetlana (new sensor) 6L6GC to the Tung Sol 7581. Those looked identical to each other and sounded very much the same. As for the true Svetlana tubes (aka SED =C=) they share nothing in common to the new sensor equivalents (not).

Just for kicks, I pulled the STR440 grays out of my MWDR since those tubes have less hours of use. TBO, I could not tell the difference between those and the STR448. The older set or original tubes that came in the JP2C have many hours of good use on them. I would say if you are looking for the STR440 replacement, the STR448 is as close as you can get, just made by PSvane vs Shuguang.

 

[Dude52]

That's great ! Thank you for these very detailed informations. I love STR440 in my Roadster and was afraid to be not able to find a similar replacement.
Did you also try and compare them in your MWDR ?
You mention that you plan to try a mix of tubes, like the STR440 + STR448 (or others combination). Is that safe to run two different pair of STR# together ?

 

[bandit2013]

That's great ! Thank you for these very detailed informations. I love STR440 in my Roadster and was afraid to be not able to find a similar replacement.
Did you also try and compare them in your MWDR ?
You mention that you plan to try a mix of tubes, like the STR440 + STR448 (or others combination). Is that safe to run two different pair of STR# together ?

It is safe to do so. Just do not mix EL34 with 6L6 as that is not possible with the non-Simul Class amps. Not sure if that could be done with the V or the VII. I did a brief test with the STR440 and STR448. Did not hear much of a difference. Also keep the pairs as pairs. Easy to do with 100W amps as usually the inner pair should match and the outer pair should match. You can mix reds with yellows or others of the same type or different type as long as they are 6L6 tubes. Probably best to have a matched quad of tubes though. If the specs match for the plate voltage, no reason why you cannot run say a pair of TAD 6L6GCSTR with a pair of SED =C= 6L6GC tubes. Different tubes, different gain response and characteristics. Sometimes you either get not much of a change or something beyond expectations. However, Class A/B amps like the Roadster, MWDR or JP2C, mixing different 6L6 tubes may not achieve much. Usually with the Simul Class amps it can be different experience.

Now, after this mornings play through, I am overwhelmed with joy. They have surpassed the STR440 sound in many ways I did not expect. I have entered into a new Honeymoon with the JP2C. At first they sounded very close to the STR440. Just a slight more low end and upper chime on clean channel. This morning they are not more aggressive than I have ever experienced in the JP2C. So tempting to try these tubes in the other Mesa amps. Not sure what to expect though as they are a bit different, more so than I first thought they were. Beefy, chunky, punch and lots of midrange complexity with a top end I have yet to get into ice pick but I am sure I can dial in the amp to do that. I will not run them in my Mark V90. That amp has retired. However, they are taller than the STR440 tubes, could not get the cage in place as it did not fit. I sort of fear I may break off the plastic post as it is difficult to get into the JP2C as it does not have very much room.

I have not tried the tubes in the MWDR or Roadster. Would have to dig them out from storage. I think I still have the MWDR out as I was experimenting with that amp and my pair of Badlanders. Not sure what to expect with the Roadster as that is a dark amp to start with. The 448 have more sonic potential in the low end and upper range as I am finding out.

From what I understand, Mesa is matching up the STR445 tubes with the Rectifiers. I am a bit weary on the JJ power tubes as I had some issues in the past with them. At least Mesa has tested and approved them. Best to use the Mesa certified tubes in my opinion.

I have tried other STR440 tubes in the Roadster, namely the gray color coded ones, they were too much for me. I sort of prefer the yellow color code in the Roadster. Grays are good in the MWDR. Since I retubed the Roadster with some NOS tubes in the preamp section, my results may vary from yours if I get around to trying them out in the other amps. May want to hear them in the Badlander as well. I am waiting on another set of tubes from Mesa so when I get them I may explore them with the other amps in question.

Perhaps after I get some weekend errands done, I can try them in the Roadster if there is any time left since I have to move the JP2C rig away from the door. Not sure what to expect. May as well try the MWDR and Badlander while I am at it. Since I still have the 412 cab out, I will see what I can manage.

 

[bandit2013]

Just in case I break them, I placed another order for a quad. Always good to have backups. Not sure when I will see them as I got word through Mesa Customer Service they are taking some time getting batches in. Typically 6 months. I was surprised I got my first set so quick. However, I talked to someone in Nashville and not Petaluma so things may be different when you actually communicate with Mesa people vs Gibson people.

 

[bandit2013]

Well, that was unexpected. Never thought the Roadster could be so bright.
CH3 and CH4 in modern did not matter if I ***** diode or tube tracking. Bright enough to run a 7 string without getting muddy.

Two things could have been at play: NOS tubes in the preamp or the cabinets.
Decided to pull the chassis out as I do not like fishing around to get the tubes in around the one transformer. Loaded up with the Stock Mesa tubes and tried again. I just did not feel like moving the RA100 of the 412 cab, I am lasy.

Any how. Change in the preamp tubes did not make any difference. There was some low end but had to actually push the bass and midrange all the way and back off on the treble and presence. Good enough for the 7 string even when pushing the sound barrier or my hearing threshold of pain. Bright.

Loaded the STR440 yellows back in, Not as bright but much brighter than it normally would be. Must be the two vertical 212 cabs running in parallel. First time I ran the Roaster on two vertical 212 cabs. I would not doubt it is the speaker load more than the tubes. Or that the amp has lost a cathode bypass cap or has a stuck relay. It was back to being muddy with the 7 string. If you do opt to get the STR448, you will not need any boost pedals to brighten it up and shore off some low end.

Perhaps the Rectifier is coasting too much with the 6L6GC tube. Not the effect I was expecting. It did not sound bad, just bright as hell but not to the level of being an ice pick. Really different experience with the Roadster. I doubt I will try these tubes in the MWDR or Badlander as both of those amps are much brighter normally than the Roadster. I hope it was just the cabinets. However, I ran the same cabs with the JP2C and STR448, plenty of low end grunt and had some punch to go with it. Not sure the STR448 is a good candidate for a Roadster. Just my take on how things sounded.

 

[bandit2013]

I believe I see what is going on here. It was not the cabinets at all. It is more about plate voltage/current. Typically I had issue with the JP2C at reduced volume levels such that the low end was in a dominant state and shred voice was the only way to compensate for that. The STR448 does not swamp the amp in the low end when you run at bedroom levels, I do not need the shred voice as the bass, mids and treble remain in good balance. Still it does not rule out any issue I may have found with the Roadster. I had the same issue when going back to the STR440. Low end was there, just not a swamp like it used to be. I will see how the MWDR behaves at some other time. I did order another set just to have them on hand. Getting them in and out of the JP2C is tight, feel I may break them if I keep pulling them out of the amp. However, my curiosity has grown and I want to find out...

 

[bandit2013]

Time to figure out what is up with the Roadster. Very odd I do not have much low end. I can hear it and the tone stack responds properly. Just lacking the bottom end in the power section. Since this issue of brightness affected all channels, it could only mean the phase inverter tube or something is up with the OT. Since all channels use feedback of sorts from the output, is it related to the power tube swap? Unknown. Bummer. I will respond back once I figure out the issue and retest it with the STR448. May try the MWDR but want to confirm it is not power tube related first.

 

[bandit2013]

Update on the Roadster with the STR448.
For some odd reason the stock STR440 tubes I had in the amp also were super bright in tone. Something was up with the 4 ohm jacks as I suspected. Ran the amp on the Mesa Standard 412 cab and all was back to normal. Must have been a spider in one of the 4 ohm jacks, they do not conduct very well. Had that happen before. Need to get some of those spider plugs Mesa places on the extra jacks on speaker cabinets. That should help to keep the buggers out. Anyway now that it was back to its normal tone and characteristic, I changed power tubes from the STR440 to the STR448 (I waited for them to cool down first). Ran all of the modes on each channel. Clean/bold sounded normal. Tweed and Brit had more hair. (Brighter). Been a while since I ran those voices. I did not bother to dial them in as I wanted to get to CH3 and CH4.

Raw/Vintage I thought sounded much better than they ever did. Modern on both channels, one with diode tracking (CH4) and the other with tube tracking (CH3). Overall, it was nothing like the STR440. Much tighter in response. Plenty of low end when palm muting but did not seem to flood the sound too much. Pick attack is also more defined. Instead of using the word bright, Crisp is more like it. I did mess with the bass, midrange, treble, presence just to get a feel for these tubes in the Roadster. It would probably take a few days before I would say they are better than the STR440. In some respects they are, and in other respects they are not better. Still as aggressive so that did not change much. Amp is not as loose. I even pushed the boundary of my hearing tolerance just to see how things change with more global volume vs channel volume. The STR448 tubes make the Roadster sound more like the MWDR. Almost a different amp. Note that the color codes on the STR448 are gray. I much prefer the yellows in the STR440. I have tried the gray STR440 and thought they were too much. On a brief play through with the STR448, it is good but not stellar like I found them to be in the JP2C. I also tried the spongy power mode just for kicks. First time I took notice to the change in loudness. Perhaps I just did not notice it much with the STR440. It has been a while since this amp has been used as a main rig.

As for getting them, they are on backorder and may take 6 weeks to 8 weeks before they hit dock and get through customs to Mesa. Then testing and sorting, packaging.... I can see it could take 3 months to make it into distribution. I am sure there is much for than that involved.

I sort of wonder what the STR445 tubes sound like in the Roadster. Those are the JJ 6L6GC tubes.

 

[Dude52]

Thank you very much for your very detailed answers, you rock !!! In conclusion, would you say that STR448 are sort of STR440 with a tighter character ?
I was also interested by your remark about grey vs yellow (STR440). What do you mean by they were too much ? I have some Yellow as a a spare but also Blu (that I never tested).

I also wonder how behave STR445 vs 448 in a Roadster (I found a YouTube video and they look tighter, with less low end). I love my STR440 but it seems no "new" tubes are really similar.

 

[D-Lish]

I neeed 4 E 84 for my DC 3 . Are they getting or are they hard to find? Also seems i need the 12 AX7 anda power tube for this amp.

 

[bandit2013]

Thank you very much for your very detailed answers, you rock !!! In conclusion, would you say that STR448 are sort of STR440 with a tighter character ?
I was also interested by your remark about grey vs yellow (STR440). What do you mean by they were too much ? I have some Yellow as a a spare but also Blu (that I never tested).

I also wonder how behave STR445 vs 448 in a Roadster (I found a YouTube video and they look tighter, with less low end). I love my STR440 but it seems no "new" tubes are really similar.

This is a convoluted concept so it may be a long post:

If I understand the color codes correctly, Red has the least early gain characteristics. White has the most early gain characteristics. Considering a fixed bias amp, The reds will not get into clipping as easily as the whites. In other words, you will have more headroom with Reds vs Whites. The color codes I think run Red, Yellow, Green, Gray, Blue, White. The green and gray codes sort of fall into the middle. Not sure how much of a difference there is within the narrow band of tube gain for the fixed bias design. Another key to understand is how the tube responds to frequency. I would assume the gain response is different at lower frequencies vs higher frequencies. The STR440, STR443 are similar such that the low frequency response is much stronger than say the STR448. So when a tube with early onset of gain or tendency to clip for a given signal level is used an a bass dominant amp, it can get muddy until the signal strength of the upper frequencies gets higher in magnitude. Example, the STR440 or STR443 having the same color code would be bass dominant in the JP2C at a reduced volume. The only way to compensate for this was to use shred mode in order to get more influence on the upper frequencies. Even at gig level, it became a burden to some extent. The STR440 had an advantage over the STR443 as it seemed to reveal more upper frequencies and harmonics at gig level. Comparing that to the STR441 in the JP2C they seemed too relaxed. Not best for this amp. The STR448 on the other hand, did not follow the same frequency gain characteristic. It was more balanced. So at reduced volume the low end and upper end was at the same volume and note definition was retained. At gig level the low end bloomed as well as the rest of the frequency range such that it was an epic experience. WOW, I cannot believe what I am hearing sort of deal. Note that a Mark amp sounds best when it can get into power tube saturation and clipping. Ideal when the power tube does not have a low frequency dominance. There is plenty of low end, probably more than I expected but it is quite different than the STR440. Just a tad looser but yet just as tight. Hard to describe.

For the Roadster, that is a different amp in its entirety. More of a low end sub-harmonic generator due to the cold clipper and the following tone stack lends itself to difficult to manage when the power tubes tend to be more low-end dominant. STR440 yellow would have more headroom than the gray. Not sure how much of a difference but you can hear it. What I mean by too much, too much bottom end and the early clip effect did not provide enjoyment. More of a muddier tone and lack of definition. I did not want to push the amp with stupidly loud settings in hopes the top end would eventually be noticeable. It does not take much plate current to make a difference in characteristics. In some respects, it could be related to being more familiar with one given color code in the amp vs the other. If there was not much of a difference between the color codes, why have them in the first place? When you feel you need to dial out specific settings on the parametric tone controls (Bass, Midrange, Treble) it may be the power tube is too dominant in one particular frequency that lends itself to be undesirable. Sometimes you can compensate but sometimes you cannot. The early onset of clipping of the Grays was one of those cases for me. Yellow in the Roadster had more content without the mud. Never tried the reds though.