Sweetwater is showing "new" mesa tubes

[bandit2013]

Now it gets even more complex once you bring in the Simul-Class amps. I am so tempted to try the STR448 in the Mark V 90. For instance, the STR440 reds were the stock tubes. I would assume if this was selected by Mesa for a reason, it would be due to the extended class A portion of the power amp running a hotter bias than the Class A/B section. The extended class A section was more prone to red plating than the class A/B section. The iconic SED =C= 6L6GC provided a full body of tone from low to high end along with this 3D complexity that was unrivaled. Those same tubes used in the JP2C was bright and lacked any low end. Almost sterile in a sense. That is what I felt about the STR443, a bit lacking in musical content. The same can be said about the STR441 but those were sterile compared to the STR443. Just for fun, I ran the STR441 in the Badlander and I was not disappointed. I should try the other tubes in that amp just for kicks as it has a well balanced tone overall compared to the Roadster or MWDR that runs with that sub-harmonic content. BAD, Roaster, and MWDR all have the cold clipper and the cathode follower tone stack driver but the difference is in the cold clipper cathode resistor, Roadster and MWDR share much in common with the older Rectos (including the Stiletto) which is the 39k ohm. Badlander has some changes and it is now a 15k ohm. The gain stages that drive the cold clipper may be different as well as the plate resistor used with the cold clipper stage. It would not be as simple as changing that cathode resistor to a lower value as I did try that with the Roadster, lost most of the desired gain structure. Not why the amp went bright, that is related to the OT and 4 ohm jacks. Sorry, I am going on a tangent here.

When it comes to tubes, it is just as subjective as speakers, guitars, pickups. A rabbit hole I try to stay out of but here I am.

Bottom line, the STR448 in the Roadster had a different character than the STR440. I felt that familiar sound was now gone. It was not bad, just different. I needed to run the amp at a higher volume level to get the same low end sound. It had bass, much tighter response than the STR440. Not sure I liked it or hated it. I do not use the Roadster all that much anymore. I am more hooked on the Badlander or the JP2C (now that I have rediscovered the amps potential with the STR448). Makes me wonder if the Roadster was designed around the use of the STR440 since that was MESA's staple power tube they used with every amp for at least the past 10 years. I have not tried the STR443 or STR441 in that amp. If I feel up to it I could do a run through with the different tubes, namely the STR443 or STR441 but may be pointless as they are difficult to get more so than the STR448. I have seen many good reviews on the TungSol 6L6GC STR tubes on Sweetwater. Those are the same tube as the STR441. Also what I have seen being used in the Mark V90 as the preferred tube (look at Mesa's website, they show the STR441 in the MKV). I will give those a shot this weekend. When it comes to non-mesa branded stuff, not sure how they are sorted or tested. I have bought tubes before that were not Mesa certified, I generally state the amp I intend to use the tubes in. Most places I have purchased from did a good job with the power tubes. (Thetubestore, Tube Depot).

 

[bandit2013]

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.

If I was a tube broker, I would be able to direct you in the right direction. I am not familiar with the EL84 tubes and how they behave in the Dyna-Watt design. There are a few varieties of the EL84s. Some are EL84/N709 with the Genelax (Gold Loin brand), some also listed as EL84/6BQ5 which are more standard. I never owned an EL84 based Mesa amp so I cannot comment what would be best for your application. Perhaps someone more familiar with the DC series could help guide you in the right direction. Try posting in that forum and see what comes of it.

Trying to find the 12AX7 seems to be out of stock everywhere (those sold by Mesa or with the JJ brand which are both JJ ECC83 tubes). I took a quick look at the DC3 schematic (from an online resource) just to confirm this amp does not have any cathode follower circuits. It does not. Safe to use any 12AX7 tube. Mullard CV4004 is a decent tube (it is a 12AX7). For the phase inverter, you could probably use a Mullard 12AX7 (reissue long plate) or Sovtek LPS (basically the same tube). Tung Sol 12AX7 or EH 12AX7 are sort of similar but with different tones to the CV4004. Hard to say how the DC-3 would respond to tube swaps. Since each amp is different, the end result may be great or sound or not to your liking. The closest tube I ever found that sounded like the Mesa 12AX7 ( JJECC83) but better was the RFT12AX7A but those are very scarce and not readily available, plus they are expensive due to limited availability. Other than that, I liked the Mullard CV4004 but only have reference of their use in a Mark V 90W or the Royal Atlantic RA100.

 

[TRENCHLORD]

IMO they have always coded their tubes the opposite of how it should be.
Reds and yellows run the coolest(bias) , but those are "warmer" colors.
Whites and grays run the warmest(bias), but those are "cooler" colors.

Just nitpicking!

I really like the combo of 440 and 420 together in rectifiers.

 

[bandit2013]

IMO they have always coded their tubes the opposite of how it should be.
Reds and yellows run the coolest(bias) , but those are "warmer" colors.
Whites and grays run the warmest(bias), but those are "cooler" colors.

Just nitpicking!

I really like the combo of 440 and 420 together in rectifiers.

I am not sure I understand. If you are saying Reds and Yellows run the coolest bias, on a fixed bias amp, it would have early gain characteristics. Perhaps they run cooler than normal hence more headroom before clipping. If the bias was adjustable, to get the same characteristic as the grays and blues, I would need to adjust the bias for more plate current. The opposite would hold true for the other side of the spectrum.

Red hot is not as hot as white hot. Gray reminds me more of ash, blue is the burnt effect of steel when it gets overheated and green never happens unless you toss it out into the back yard and moss starts to grow on it. (actually here on the east cost of NC it is mostly swamp so everything turns green). Would rather not think about it. What happened to the number system. Oh, that is Groove Tubes (bought by Fender, then shut down for good).

As for the color codes, I have seen it described this way or that. I give up. Greens and grays are in the middle so those would be ones to seek I would assume. Depends on the amp in question. Perhaps with a Simul-Class amp, you can run a cooler tube in the class A sockets and a hotter tube in the class A/B sockets. Odd that the Mark IVb was one I could blend different tubes of the same time to get some really awesome sounds. Tried a similar approach to the Mark V90 and did not get anywhere close. Different design will have a different effect.

Now that I have another set of glass to run with the JP2C (Mesa STR415 arrived yesterday, direct from Petaluma) I have a chance to try the STR448 in some other amps. Badlander, MWDR. May roll out the Mark V90. I like the STR448 in the JP2C I ordered another set for backup. It will take some time to get due to it being a new thing for Mesa and such. Time to explore what the STR448 sounds good or bad in. the Roadster test was not all that bad. I still think there is something amiss with that amp.

 

[bandit2013]

I finally got around to running the STR448 tubes in the MWDR. There was more tube saturation effect with those tubes. I would not say muddy but more content made the amp sound swamped. Almost felt like the amp needed a GEQ in the FX loop to compensate. Odd, The STR448 color codes are the same as the STR440 tubes and did not expect the dumble effect of power tube distortion. I did get something like that when comparing the STR440 yellow to grays in the Roadster.

Did not try the Badlander with those tubes yet. I should try them in the TC100 while I am at it. Forgot that amp can run 6L6 tubes as well.

 

[TRENCHLORD]

I am not sure I understand. If you are saying Reds and Yellows run the coolest bias, on a fixed bias amp, it would have early gain characteristics. Perhaps they run cooler than normal hence more headroom before clipping. If the bias was adjustable, to get the same characteristic as the grays and blues, I would need to adjust the bias for more plate current. The opposite would hold true for the other side of the spectrum.

Red hot is not as hot as white hot. Gray reminds me more of ash, blue is the burnt effect of steel when it gets overheated and green never happens unless you toss it out into the back yard and moss starts to grow on it. (actually here on the east cost of NC it is mostly swamp so everything turns green). Would rather not think about it. What happened to the number system. Oh, that is Groove Tubes (bought by Fender, then shut down for good).

As for the color codes, I have seen it described this way or that. I give up. Greens and grays are in the middle so those would be ones to seek I would assume. Depends on the amp in question. Perhaps with a Simul-Class amp, you can run a cooler tube in the class A sockets and a hotter tube in the class A/B sockets. Odd that the Mark IVb was one I could blend different tubes of the same time to get some really awesome sounds. Tried a similar approach to the Mark V90 and did not get anywhere close. Different design will have a different effect.

Now that I have another set of glass to run with the JP2C (Mesa STR415 arrived yesterday, direct from Petaluma) I have a chance to try the STR448 in some other amps. Badlander, MWDR. May roll out the Mark V90. I like the STR448 in the JP2C I ordered another set for backup. It will take some time to get due to it being a new thing for Mesa and such. Time to explore what the STR448 sounds good or bad in. the Roadster test was not all that bad. I still think there is something amiss with that amp.

When I think of reds and yellows it makes me think "warm", but in the mesa code system they are actually the "coolest" or "latest" breakup.

Whites are a "cooler" color, hence "cool white" bulbs at a lighting store. In the mesa code system whites are the "warmest" bias which is why the breakup the earliest.

They are indeed a fixed-bias amp, but they are not a 100% locked-bias amp. The range they will safely run is encompassed by their code system.

 

[bandit2013]

True, staying within Mesa's specified range will ensure you have some function. Some may sound more different than others within that range. Mesa stated you will not be able to tell the difference from Reds to Whites. I beg to differ when comparing the same STR tube with some amps like the JP2C, Roadster, and MWDR. I can tell the difference. For example STR440 red to Gray which is something that would be easy to find in the 6L6GC category. I have only seen Blue in the EL34 types. All of the 6V6 tubes I have fall in the Gray code. (STR417). I use those in the California Tweed or have used them in the TC-50.

Just for kicks. I ordered a quad of the STR445 as I have not tried those out yet. Sine Mesa is promoting that tube for the MWDR, chance they will sound good in the Roadster is likely. That is how they were described on Mesa's website, but they changed the description to make it more generic and not amp specific. If you look at the current product line, they are showing in good detail what tubes they promote with each amp. STR445 in the MWDR and Mark VII, STR441 in the Mark V90 and the STR443 in the JP2C. It is unfortunate the I felt the STR448 were a bit off with the MWDR. Perhaps I am used to hearing the other tube and did not want to adjust to it.

Also want to see if there is any difference of the tubes listed above in the Mark V90 while I am at it. Have not used that amp in a long while.

 

[Synaptix30]

Would like to hear your opinion of the str448 in the mark v90. Those are the only power tubes I can get for my amp at this moment in my area, but hesitant to commit to a quad set if they're not great.

 

[bandit2013]

Would like to hear your opinion of the str448 in the mark v90. Those are the only power tubes I can get for my amp at this moment in my area, but hesitant to commit to a quad set if they're not great.

I just got done running some tube trials with the Mark V90 as of last night. I took notes how I felt the tubes performed before I forget what I liked or disliked with each channel and associated voices. Note that I have never bonded with the Mark V 90 I have. it has some ice pick tendencies on the desired channels and the clean generates this audible hum that is unavoidable. Since I converted my V to a combo, I chose to install an EVM12L Classic speaker as I could not tolerate the V30 with this amp. Sure the EV can bring out the worst of any amp connected to it. My tests were done with the EV speaker and I compared the SED =C= 6L6GC, Preferred Series 6L6GC STR, Mesa STR440, Mesa STR443, Mesa STR441 and the Mesa STR448. I do have STR415 but will not run them in the Mark V90. So I do not flood the post with every tube I ran with the Mark V, I will keep it simple to the request of the STR448 (topic) and what I felt was the best sounding tube I have tried last night and this morning.

STR448 were just ok. Overall, they had more midrange content, softer low end but yet manageable and much brighter than the STR440. In my opinion, not the best choice for the V90. I thought it would be really good as it is a Simul-Class amp. Nope, not this time. There is another tube that blew me away I will bring it up after I discuss the 448.

CH1 FAT: Wow, the STR448 sounds great with the clean channel. It almost rivaled that of the SED =C=6L6GC which to me is the staple tube for the Mark V90 on all channels and voices. This is where we part ways with perfection. I will refrain from referencing a tube that is out of production and difficult to obtain with the exception of the STR440 that may have been the choice tube since the Mark V came out.

CH2 edge: my least favorite voice, but actually sounded decent. Still thin sounding. Probably best used with a 7 string.
CH2 Crunch: Well now, that was a huge surprise. I was getting tones from the crunch that sounded very similar to the Triple Crown Blue channel (2, low gain). Not as good though as the midrange content was swamping the tone. The 448 were starting to remind me of the Gold Lion KT77. The Voice of the Mark V is really coming out, sounds like a mimic of a Brit amp of sorts. That voice carries on with CH3 as well.
CH2 Mark I Not bad, I could go for this. Thought the STR440 sounded better. Too thick in tone and was not easy to compensate like it is with the STR440 tube.

CH3 IIC+: On the thin side at reduced volume. Has plenty of bite and grit when pushed. It has a loss of definition though. More midrange content than I desire. Sort of Tolerable but bright and swamped.
CH3 IV: Just more of the same from IIC+, could not tell the difference except for more midrange and too much of this and that. Tone controls were usable as was the GEQ but did not like the end result.
CH3 Extreme: Was not blown away. Much brighter and more flooded with undesired overtones.

I did try the STR448 with a vertical 212 cab (V30) and felt it was on the brittle side of tone. Not to my liking. The STR440 were much better with the V30 loaded cabs.

My recommendation:
Out of my stash of power tubes, I decided to try the lame duck. I tried them in the JP2C and they were a total flop, more bland and sterile in the JP. However, Mesa is promoting this tube with the Mark V 90W so why not give them a try: STR441? Well damn, they are not lame in the V90.

Overall: Best I have heard yet in the Mark V 90 considering the tube is still in production. They are in stock at ZZsounds. Not sure where you are but you may find them if you look. Guitar center does not have anything. Sweetwater. I was blown away that these tubes sound really good in the Mark V90. Ran the amp through all power modes (did not try the variac power though). Every voice on all channels. The STR441 delivered the goods. I took it one step further and tried the Vertical 212 loaded with V30. No ice pick.

I still have to get the Mark V90 back into its combo shell.

I will have to admit the STR441 were a game changer for me, I actually like the Mark V90 now. Even edge voice on CH2 sounds great. Still thin but not an ear piercing experience. The thing about the STR441 is they have a well controlled midrange content. It does not overly influence the overall tone. That dominant midrange I struggled to get away from was finally gone. I now see why Mesa has chosen this tube for current Mark V90W production. it is that freaking good. So many times I was tempted to toss the amp, or get rid of it one way or another. Now I am glad I still have it. I may have to get some more of these tubes for my stash.

Top of the tube is clear glass. One side of the tube is also clear. This is one of the Russian tubes that has a dual getter design. They are attached to the plate seams and are bent to face the one side. Not sure if that makes a difference or not. Best of all they cost less than the STR448. Not sure how easy they are to find. Probably like most other tubes, hard to get. STR441 is the TungSol

Between SweetWater, AMS, and zzsounds, there is only one set. zzsounds and AMS may share the same inventory. Hard to say. Musicians Friend and Guitar Center are essentially the same. Well damn, all I see is the STR448 just about every where you look. I would recommend searching for the STR441 tube for the Mark V90.

The MESA STR441 is the Tung Sol 6L6STR tube. TungSol is also printed on the base of the tube but covered in part by the Mesa test sticker. Just as a reference only. I did see that zzsounds will be getting more STR441 in by July 26. They should only cost $75 per pair, at least that is what most that list the tube on their website are selling them for.

https://www.thetubestore.com/tung-sol-6l6gc-str

 

[Synaptix30]

Wow what a detailed post. My Mark V90 came stock with the STR441 but I think they're wearing out and making some weird sounds.

Do you have any experience with the STR445? I believe those are the stock choice for the Mark Vii. I think I am able to get those locally.

 

[Dude52]

@bandit2013, thank you very much for your very detailed answers, appreciate a lot

 

[bandit2013]

Wow what a detailed post. My Mark V90 came stock with the STR441 but I think they're wearing out and making some weird sounds.

Do you have any experience with the STR445? I believe those are the stock choice for the Mark Vii. I think I am able to get those locally.

I ordered a quad of those to try out in the MWDR and Roadster just a few days ago. It will take a few weeks before I see them as they are on backorder like everything else. I was surprised to see the STR445 in the VII. Really??? I know Mesa recommends them for the MWDR. When I get them, I will let you know if good or bad. Just keep this in mind, I sort of have a negative bias towards my Mark V90. Mostly because it is an ice pick and just never bonded with it. TBH, the STR441 changed by view on the V. It was that dramatic of a difference. Most of the ice pick has been resolved but the midrange or voice was just annoying. STR441 was the one filter I never expected that would reduce to remove some of that midrange I found irritating. I guess that is what they mean by tucked midrange.

So let me ask you, what was your impressions on the STR441 tubes in the Mark V90? How long have you had the amp? 2020?

Also what weird sounds are you hearing? It may be power tube or could be preamp tube related.

 

[bandit2013]

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

My apology to you as I have hijacked your post. Sorry about that.

 

[bandit2013]

Hmm, Badlander 100. Is that one amp that fell off of the Rectifier shelf? Matters not to me, one of my favorite Mesa. So I have run the STR440 in that amp and compared it to the STR447 (EL34) in the other Badlander. It is almost hard to tell the difference once you make the adjustments on the amp with the 6L6 tubes. We are talking minor changes to the presence and treble. Also did the same with the STR441 some time ago. Today, why not give the STR448 a try. At least I know where the second set of STR448 will wind up. In the Badlander. It was not that dramatic of a change and got very similar results with the other 6L6 tubes when comparing to the EL34. Not really sure which I prefer. I am so used to the EL34 (STR447) in that amp but the change was great with the 448. A touch of more low end and the rest was about the same except for the EL34 were slightly more brighter than the 6L6. Once I let the tubes cool down, I will try swapping the EL34 in the other bad with 443. May even try the 441 and 440. For sure I will try the STR445 when they arrive. I am not displeased with the STR448 in the BAD. They were good in the JP2C. Surprised they did not perform well in the Mark V. Maybe in a different color code say in yellow or green would be better. Sort of had that issue with the STR440 when pairing up with the Mark V and the Roadster. Seemed that reds, yellows or greens were good, grays too much midrange and swamps out the character I prefer. Then again, it is based on my opinion and that is subjective. Bottom line, the STR448 were too bright in the Rectifier (Roadster and MWDR) such that it was not easy to compensate with the tone controls or presence to regain that Recto sound. There are differences in the phase inverter circuitry and feedback circuits so I would not expect each amp to behave the same with different power tubes. At least Mesa made this a bit easier by pre-loading what they feel is a better power tube choice in each amp. I would say they got it right with the STR441 in the Mark V90W. No clue yet how the STR445 stack up with the Rectifier. As for the JP2C, the STR415 (NOS) would the true benchmark or holy grail (not inexpensive and are very limited in what is available). STR448 is good for the JP2C. Works in the Badlander so that is a win for me. Power tubes should be cool by now. Will have to hear the difference between the STR440 gray to the STR448 gray. If I have time, will try the STR443. Still not going to record anything, sorry for that. Hearing it is what really matters. At the moment, I have all of my amps out and have not physical room to get any recording gear setup.

 

[bandit2013]

2BAD on 6L6GC was f-ing amazing. Still have lots of love for the STR447 EL34 but I was getting plenty of floor vibration out of the two amps on the 6L6 power, more so than expected. Both amps were running the Mesa Vertical 212 cab. STR448 in one and STR440 in the other. I was using the Mesa Switch track to switch between both amps or run them at the same time. Had all of the controls at noon (except for the channel masters). STR448 does have way more midrange and low end content than the STR440. The STR440 tubes sound like they are scooped in the midrange. Low end was strong but not as pushy as the STR448. Top end was brighter with the STR440. Now for the STR443 vs STR448. The 443 seemed to have less low end not quite as bright as the STR440. More low mids to high upper mids and a bit more thinner sounding top end. Sounded like taking the bell shaped frequency response and shifting it up a few hunderd Hz and changing the slope at the upper frequency to a steeper curve. The 443 sounded on the fizzy side in the Badlander. I did not get that effect with the JP2C and STR443. STR448 sounds much darker relative to the STR443 and STR440. That low end grind does sound great. I think I found a home for the STR448 (Badlander 100). Not that it really matters as they are not identical tubes, the STR448, STR440 and the STR443 have the same color code of gray. I believe the STR441 were green. I have nearly run out of amps. Different amps will have a different characteristic. For now, I am done with chasing the grail tone. I can wait until the STR445 arrive to start up again. I doubt I will try them in all of my amps. MWDR is a given as well as the Badlander and Roadster. Not sure I will run them in the Mark V but I am sure the temptation will be there.

 

[bandit2013]

Just for kicks, I will try the STR448 in the TC100. My curiosity is eating at me. It will be that amp or the TC50. Never cared much for the TC with the 6L6 tube so this may be interesting. If I did not have a new set of NOS STR415, the STR448 would still be in the JP2C. I would not be able to decide which I like better, 448 in the BAD or in the JP2C. The TC100 or TC50 will be the last stop for the STR448 before they reach their final resting place in the Badlander.

 

[bandit2013]

STR448 in TC seems to have a power reduction. Any 6L6 tube seems to have that issue. I tried it, EL34 much better.

 

[bandit2013]

Just keep this in mind, don't base your decision on my comments alone. Since I only have one set of the STR448 with the gray color code, that just may be part of why I felt they did not do well with some amps as I found similar effect with the different color codes of the STR440 in the same amps in question. I do have another set on order. When they come if and if they are not gray codes I may explore the other amps again. Not sure much will change though. Sorry if I did not give you what you wanted to read on the subject. I am sure others have bought this tube, what is your opinion and what amp are you using them in?

 

[cgscotto]

I just received two quads of the Mesa STR 448 Red base from Sweetwater. I also have three quads of the TAD Red Base 6L6. While everybody has noted they look identical, they are, in fact, identical. I have not seen this detail mentioned in the thread. On the Mesa quads I received from Sweetwater, if you turn the tube upside down and read what is says on the base, you will see TAD GERMANY, which is, obviously, what is on the bottom the TAD quads.

Three of the duets I received from Sweetwater were GRN and the other duet was rated YLW. I tested all four quads on my Orange VT tube tester (I know not the best, but it does give me useful information, such as matching numbers). Of course, all of them tested good, but the matching numbers were interesting. Two duets of GRN gave me matching numbers of 8 (the matching numbers also indicate how hot the tube are), the third duet was rated 7, and the YLW was rated 7. For comparison, the two TAD quads all consistently gave me matching numbers of 8.

I bought the two quads of TADs from Amplified Parts, and told them in which amp I would be using them, JP-2C. I'd say, based on the matching numbers returned by the tube tester, they did a pretty good job of selecting the tubes.

I had a third quad that I put in the JP-2C about a year ago. I liked the tone. It was a bit better than the Mesa 440 Grays that came with the amp and also a bit better than the TAD Black Plate 6L6s that replaced the Mesas. I felt the frequency range was more balanced, power was great, and the sound more detailed. Unfortunately, one of those TAD Red Base tubes red plated. I got a replacement from Amplified parts and bought a quad of Tung-Sol 7581As, which is what is in the JP-2C now. I like these tubes as well, but when they wear out, I will probably put the TAD Red Base back in the JP-2C.

As far as price goes, Amplified Parts sells a single TAD Red Base for $35, a matched duet for $70, and a matched quad for $140. The Tube Store sells a matched duet for $90, and of course Mesa sells a matched duet for $99. I think the extra $9 dollars is worth the cost over The Tube Store to preserve the warranty on my new Mark VII while still getting the benefit of using a TAD Red Base tube (my JP-2C is out of warranty). Amplified Parts has the cheapest price at $140 a quad, but one of their tubes did red plate. I have had Mesa tubes red plate, so I am not inclined to put too much weight on that metric. The V1 tube in my new Mark VII went microphonic about a week after I received the amp. Moreover, the tubes Amplified Parts sent seem to be rated just where Mesa rates their tubes.

The next step will be to break out the bias probe and measure the actually mA the tubes draw in the amp. For that, I will have to pull the chassis, and I think I would rather practice then spend time on that at the moment. I may, however, pull the Mesa tubes that shipped with the Mark VII, which are JJ's, which I do not like in any amp expect my Triple Rectifier. Of course, I will put in one of the Mesa quads in the Mark VII. If I do I will report back on how they sound.

 

[mace]

Any thoughts on the VII? How are you liking or disliking it?