Time to re tune the pre’s (DR MW)

[Dreamin90s]

Picked up a used 2018 mesa dual recrifer multiwatt. I think v1 might be going microphonic.
I already swapped out the 6L6 str 440’s (blu 10) that were still factory. At the time Mesa was out of el34’s so I got a quad from Eurotubes. I ran el34’s in my rev g back in the 90s. Helped with the mid scop. I pulled v1, guy at Eurotubes said yes, that appears to me a Mesa branded JJ, not Chinese that some got.
I’m not displeased with the tone, I do feel this thing doesn’t have as much gain as my old rev g but whatever… I was going to start with just v1 & v2… I’ve read somewhere that the Mesa branded JJ’s have a little less gain than straight up labeled JJ’s, true?

I’m not really a lead player, more rhythm stuff. Tones I like are soundgarden, aic (I know Jerry used Marshalls, but I use el34’s lol) pretty much moderate to high gain 90’s heavy rock..I’ll hit the modern channel sometimes for stuff like the Melvin’s, deftones white pony era etc… I play Les Paul’s with 498ts, 57+ and burst buckers… I don’t boost the amp. I run it on spongy with the recto tubes…


Thoughts on a tube for v1 or 2? Oddly I decided to ask ai lol, it suggested a electroharmix in v1 the Mesa spax7 in v2 keep the stock mesa jj branded in 3-5…. Pretty crazy it spit that out when I told it the head I have and the tones I like…

Anyway, i think this amp is plenty bright, I like more a darker, wall of sound tone, but I do like note clarity as I play a lot of full chords and distant dropped tuning chords. I prefer to live on “vintage” (the old orange) on channel 2.

Suggestions on pre amp tubes to give a try in at least v1? EH, Mesa branded JJ’s (is that still what they are using?), regular JJ’s, Mesa spax7?

Thanks!

Ps - any trick to doing the pre’s ? I got lucky pulling v1 out and putting it back in. You can not see anything, just feel and pray.

 

[DrKev]

I’ve read somewhere that the Mesa branded JJ’s have a little less gain than straight up labeled JJ’s, true?

I've not aware of actual measurements anywhere to suggest that is truly the case.

Suggestions on pre amp tubes to give a try in at least v1? EH, Mesa branded JJ’s (is that still what they are using?), regular JJ’s, Mesa spax7?

JJs are good tubes. I've had no issue with them for 20+ years. The bonus (in my opinion) is that they are a European Union company and factory and thus bound by better employee protection, health and safety, and environmental laws than any other country making vacuum tubes. And they're not Russia. In my book, that's a very easy choice.

In my amp V1 seems to be the most sensitive to noise and microphonics so I use that as my test bed. I use a looper, or plug my iphone into the front of the amp with a test tone or white noise, clean channel run clean, run a mic or effects send to my DAW, put different tubes in and pick the ones that give the best output and lowest noise. Yeah, it's a lot of work but I enjoy that (and 'thanks' to Long Covid, I have the time to do it, if I have the energy). In doing that I've never noticed a particular brand or tube come out ahead of any others.

 

[bandit2013]

I have a 2018 MWDR. All preamp tubes were Mesa branded JJ tubes ECC83s. Rectifier tubes 5U4GB are EHX and the Power tubes were the STR440 (Grey) Chinese Shuguang tube that Mesa forced on us for a few decades. Actually, I sort of prefer the STR440 tubes in the MWDR and I have plenty of backups of that tube. I did try the STR445 but did not care much for the end result.

Tung Sol or EH 12AX7 tubes will be on the bright side. The Mullard CV4004 has similar gain but not as bright with a slight midrange scoop. I have not explored that many preamp tubes in the MWDR as I have with the Roadster. Different amps but similar circuits. Roadster is much darker sounding than the MWDR.

 

[Dreamin90s]

Yeah I don’t want brighter… I switched to el34’s. That’s what I ran in my rev g. Guess jj’s are the best play here for me idk…

 

[afu]

The aforementioned CV4004 is dark. If the brightness is a problem, that could be your fix.

The AI probably told you EHX in V1, because it's good at stopping noise. I put those in a Supersonic 22 and it went from unusable to dead quiet.

If you're looking for high gain tubes, the Ruby 12AX7ACZ is a JJ which has tested above the normal gain of 100. I get mine from Doug's tubes. He tests his preamp tubes and writes the gain on them if it's critical to the description.

The Ruby 12AX7AC5 HG is meant for V1 or other positions where you don't want thermal noise from the valve. I've used these in V1 for my old Rectifier.

Doug's Tubes 12ax7s

 

[bandit2013]

The tone stack driver, it is best to keep the Mesa branded JJ tube in that spot. V3 is a dc coupled cathode follower which is hard on most tubes. JJ ECC83s or a Chinese 12AX7/7025 will be best. V4 is also a cathode follower, not as hard on tubes but again, JJ #ECC83s (Mesa 12AX7) or Chinese 12AX7/7025. All of the other tube positions are fair game to use what you want. CV4004 for example. As for the phase inverter, Mullard long plate 12AX7 is good too, a bit more robust than the LPS.

I would remove the amp from the head shell, that way you do not have to keep removing the power tubes to swap in preamp tubes. Turn off power when changing the preamp tubes. That is how I do the tube rolling. Note that the JAN/GE 12AX7WA will work fine in the cathode follower locations V3 and V4 but may be a bit on the bright side. They helped the Roadster which is a much darker amp that needed to be brighter. I eventually ended up loading the Roadster with all old Mesa 1990 Bejing 6N4-J military tubes that mesa used back then. That was the first time the 7-string was compatible with the Roadster.

I even experimented with JAN 5751 tubes as well. The image is just and example and is not the MWDR. Roadster has the same V3 tone stack driver but moves the FX tube to V5 as V4 is used for the reverb. For this example I had the Mullard long plate in V2 and V6 (phase inverter). I should revisit this with the Mullard CV4004 just for fun. I think doing the tube roll in the MWDR would be interesting. Been a while since I ran with the Dual Recs. I sort of wonder if the RFT in V2 would make a change. That tube is one of the most dark/aggressive tubes I have used. However, it was recommended not to use it in V1 of the Roadster as it would have a short life in that position for some odd reason. Tung Sol is a bit brighter than the Mesa branded JJ ECC83s, The EHx is about the same, just a different gain characteristic. CV4004 has the same plate structure but may be different control grid and cathode design. They look identical but sound different.

This is a graphical representation of the tube task chart for the MWDR. It identifies where the Cathode follower circuits are (in purple). I only wish I had the schematic for this amp to see what components are different from the earlier versions as that would be helpful in tube selection.

 

[Dreamin90s]

@bandit2013 thanks for long awesome reply… one’s so for find the schematic for the mw dr and the old rev g… I have a buddy that’s an electrical engineer, he’s like get me schematics, I’ll find out what’s they changed lol but being an engineer I’m sure he doesn’t understand tone stacks etc…

So prob best to stick with mesa branded 12ax7s across the entire thing? Maybe plau around with with v1? Channel 2 on vintage (it’s like the old orange on the rev g) is where I prefer to live but the el34’s removed some of that hard mid scoop on Chan 3 modern….

Back in the day pre amps tubes just worked out didn’t… still the same theory? I just feel like I’m down a bit of gain… I have a pic of the old rev g in the studio in the late 90s, the gain for red and orange as running around 1 o’clock… I’ve got this mw dr at 2:30 ish (can’t push it anymore) and it feels more like a noon setting on the rev g.

 

[bandit2013]

It is the same theory, but now the amps are being deigned a bit tighter to work with specific tubes. Sort of tuning the amp for the tube. I found the MWDR a bit more difficult to work with different tubes. Felt the stock Mesa branded JJ ECC83s tubes were a good fit. They may be JJ ECC83s tubes but they are selected for specific characteristics. I have had other JJ ECC83s tubes from a different tube amp that sounded harsh.

Sticking with the stock preamp tubes is a safe bet. As for the power tubes, too bad the STR440 are no longer produced. I like those the best. Have not tried to find alternatives to that tube for the MWDR that is in current production.

 

[tbonesullivan]

Just reminder that rectifiers and Russian Preamp tubes with spiral filaments do not work well together. Aside from sometimes blowing up in Cathode Follower positions, which on a MWDR are V3 AND V4, if you use "spongy" mode, they may not get hot enough for the tube to emit properly resulting in very low volume. I have had this problem with both a Tremoverb and a Stiletto when using EHX preamp tubes. I believe this also applies to the Mullard reissues, LPS tubes, and others.

 

[Dreamin90s]

Just reminder that rectifiers and Russian Preamp tubes with spiral filaments do not work well together. Aside from sometimes blowing up in Cathode Follower positions, which on a MWDR are V3 AND V4, if you use "spongy" mode, they may not get hot enough for the tube to emit properly resulting in very low volume. I have had this problem with both a Tremoverb and a Stiletto when using EHX preamp tubes. I believe this also applies to the Mullard reissues, LPS tubes, and others.

Thanks, I’ll probably just change out v1 with a normal Mesa branded (jj?) 12ax7, that’s currently what’s in there… since v1 is the most important? When it comes to gain, I’ll just stick to what appears to already be in it. I’m not getting any microphonic stuff, etc… tuned out the squeal might be a bad ground on one of my Les Paul’s… when I let me hands you can hear the ground lift. Touch one string and the no goes silent.

 

[Dreamin90s]

@bandit2013 (not pre related) hey bud, you seem to really know your 6l6’s, what do think? I was under the impression the stock str 440 (blu) that came in this thing were considered harsh in the high end… they are way darker and easier to tame than the jj el34’s… I just swapped the old str 440’back in.. now that i have had some time to learn the amp, the amp sounds way better than the jj el34s… there seems to be about 3/4 different str’s available between sweetwater abs gc. 443, 445, 447 & 448…. Guess the mw dr doesn’t like el34’s like the old rev g did… or its just my application (home playing) has changd what i am looking for.

 

[bandit2013]

The buzz from removing you hands from the strings may not be a ground issue exactly. If the jack does not have a shielded cable to the controls, that usually is the issue. I had that with a Charvel that just used twisted wires, replaced it with a shielded cable and that took care of it.

V1 is somewhat critical. So is V2 this is where all of the distortion is created before it gets forced into the tone stack driver. The MWDR does have a very sensitive input. Probably why I like it as it adds to the dynamic range.

 

[Dreamin90s]

The buzz from removing you hands from the strings may not be a ground issue exactly. If the jack does not have a shielded cable to the controls, that usually is the issue. I had that with a Charvel that just used twisted wires, replaced it with a shielded cable and that took care of it.

V1 is somewhat critical. So is V2 this is where all of the distortion is created before it gets forced into the tone stack driver. The MWDR does have a very sensitive input. Probably why I like it as it adds to the dynamic range.

So just roll with the current regular mesa 12ax7 rebranded jj’s in v1 & 2? That’s supposedly what is currently in there.

What’s your thoughts on the power tubes? Like I said str 440, I’ve read are a bit bright and harsh In the highs, after running those jj el34’s for the past month I went back to them today when the amp was just giving me bad tones today… I was like it was miserable lol… I loved el34’s in my old rev g, but not in the mw, unless it’s these jj’s from Eurotubes - just pushing to much high mid that the v30s are already pushing… I fear being 8 years old and used, who k owe what these power tubes have left… they are are 440 (blu)… but currently I’m mostly happy with the tone I’m getting out of the stock factory tunes now, a lot of it has to do I finally learned this amp and quit trying to dial it in like my old rev g. On channel 3 modern, I have the presence at like 8 o’clock… rev g I ran around noon-1… I think it’s a lot to do with the application now too - I’m not figging or recording, so I’m not opening the anp up hard… I’m running 50 watt mode, spongy and recto tubes… the tone is getting better.

 

[bandit2013]

@bandit2013 (not pre related) hey bud, you seem to really know your 6l6’s, what do think? I was under the impression the stock str 440 (blu) that came in this thing were considered harsh in the high end… they are way darker and easier to tame than the jj el34’s… I just swapped the old str 440’back in.. now that i have had some time to learn the amp, the amp sounds way better than the jj el34s… there seems to be about 3/4 different str’s available between sweetwater abs gc. 443, 445, 447 & 448…. Guess the mw dr doesn’t like el34’s like the old rev g did… or its just my application (home playing) has changd what i am looking for.

For me the STR440 grey match codes were the best in the MWDR. I tried STR445 (green) and they were too much early distortion for the MWDR. Not so sure on the STR443 (those are what Mesa is using with the JP2C). I did not care for those either (in the JP2C but do not recall about the MWDR). The thing about the STR440, they sound like a nest of angry bees. That just added to the character of the amp. STR445 is made by JJ tubes. STR443 is Russian. STR441 is also Russian as well, better served in the Mark V90. the STR447 (EL34, same as EHx EL34). STR446, another EL34 tube but made for TAD (red base EL34 manufactured specifically for TAD by PSVANE- Chinese tube). These are decent but in the MWDR, not so sure. STR448 (6L6) Another TAD tube (red base 6L6 also made by PSVANE). They do have some common traits as the plates look identical but they sound completely different. The set I tried were grey as I wanted to stay within the same match code (actually the colors indicate onset of early distortion, highest head room is Red, then yellow, Green, Grey, Blue, White. Grey and Blue will have less headroom and more early distortion. Sometimes it is good, sometimes it works against you and makes things muddy. Going from one power tube to the next, those color codes do not seem to be equivalent. A grey may have way more early distortion in one tube than the other model. Most EL34 run in the green, grey, blue. I have yet to see any blue in the 6L6. Hard to comment what alternate tube will do the job with the MWDR. Probably a red STR445 or STR448 may be ok. Yellows, green, grey or blue in those tubes will be a mud-fest. I did try STR445 yellow as well. Too much gain for the power tube. Just did not sit well with me. Total loss of the grind I was familiar with. It could end up being lame too. I have the STR448 in reds so I will try them in the MWDR when I can get a chance to dig out the amp from storage. Maybe this weekend. I have not run many different tubes in the MWDR as I do not use it that much.

If you could find some STR440 in grey, those were awesome in the MWDR. That is what I am using. They are now considered NOS if you can find them and will cost more. Not much I can do to help on that for the MWDR.

 

[Dreamin90s]

For me the STR440 grey match codes were the best in the MWDR. I tried STR445 (green) and they were too much early distortion for the MWDR. Not so sure on the STR443 (those are what Mesa is using with the JP2C). I did not care for those either (in the JP2C but do not recall about the MWDR). The thing about the STR440, they sound like a nest of angry bees. That just added to the character of the amp. STR445 is made by JJ tubes. STR443 is Russian. STR441 is also Russian as well, better served in the Mark V90. the STR447 (EL34, same as EHx EL34). STR446, another EL34 tube but made for TAD (red base EL34 manufactured specifically for TAD by PSVANE- Chinese tube). These are decent but in the MWDR, not so sure. STR448 (6L6) Another TAD tube (red base 6L6 also made by PSVANE). They do have some common traits as the plates look identical but they sound completely different. The set I tried were grey as I wanted to stay within the same match code (actually the colors indicate onset of early distortion, highest head room is Red, then yellow, Green, Grey, Blue, White. Grey and Blue will have less headroom and more early distortion. Sometimes it is good, sometimes it works against you and makes things muddy. Going from one power tube to the next, those color codes do not seem to be equivalent. A grey may have way more early distortion in one tube than the other model. Most EL34 run in the green, grey, blue. I have yet to see any blue in the 6L6. Hard to comment what alternate tube will do the job with the MWDR. Probably a red STR445 or STR448 may be ok. Yellows, green, grey or blue in those tubes will be a mud-fest. I did try STR445 yellow as well. Too much gain for the power tube. Just did not sit well with me. Total loss of the grind I was familiar with. It could end up being lame too. I have the STR448 in reds so I will try them in the MWDR when I can get a chance to dig out the amp from storage. Maybe this weekend. I have not run many different tubes in the MWDR as I do not use it that much.

If you could find some STR440 in grey, those were awesome in the MWDR. That is what I am using. They are now considered NOS if you can find them and will cost more. Not much I can do to help on that for the MWDR.

lol I was typing while you were, here is what I put above…

What’s your thoughts on the power tubes? Like I said str 440, I’ve read are a bit bright and harsh In the highs, after running those jj el34’s for the past month I went back to them today when the amp was just giving me bad tones today… I was like it was miserable lol… I loved el34’s in my old rev g, but not in the mw, unless it’s these jj’s from Eurotubes - just pushing to much high mid that the v30s are already pushing… I fear being 8 years old and used, who k owe what these power tubes have left… they are are 440 (blu)… but currently I’m mostly happy with the tone I’m getting out of the stock factory tunes now, a lot of it has to do I finally learned this amp and quit trying to dial it in like my old rev g. On channel 3 modern, I have the presence at like 8 o’clock… rev g I ran around noon-1… I think it’s a lot to do with the application now too - I’m not figging or recording, so I’m not opening the anp up hard… I’m running 50 watt mode, spongy and recto tubes… the tone is getting better.


Oddly, back to what you were saying, AI tells me blu has the most headroom since white doesn’t exist anymore lol… the stock current are 440 ther came with it are all blu

 

[bandit2013]

Ah, yes, STR440 is described as being fizzy. STR443 will have a slight tuck in the midrange and will not sound fizzy like the STR440. A green or grey code STR443 may be ok. I have not tried that tube in the MWDR so I cannot recommend them or back them up with any praise. I do have the grey STR443 I tried in the JP2C, not bad. Never used them in any other amp so I have no clue how they would sound in the MWDR. I would ask in the forums for power tube suggestion. If you opt for the STR445 (what is used in the current production MWDR). Red or yellow would be your best bet. Anything beyond that will just get muddier than the yellow. The STR445 tube is a bit rich on the early distortion factor.

 

[bandit2013]

AI is completely wrong. I doubt it can tell the difference or play the guitar. I have the STR440 in every color. STR448 in red and grey. Red has more headroom grey has more early distortion. Plus, I can hear it and tell the difference. An artificial intelligence algorithm only seeks data and may use incorrect information. I would not trust AI for anything at this level of its development. If it can evolve and pick up a guitar, plug it in and power up a tube amp with the tubes in question and play and listen to the difference and then change the tubes and repeat. Then I may accept some of that information may be credible. Sorry, letting AI make your decisions is not a good idea. The last time I checked, I am human.

 

[Dreamin90s]

Ah, yes, STR440 is described as being fizzy. STR443 will have a slight tuck in the midrange and will not sound fizzy like the STR440. A green or grey code STR443 may be ok. I have not tried that tube in the MWDR so I cannot recommend them or back them up with any praise. I do have the grey STR443 I tried in the JP2C, not bad. Never used them in any other amp so I have no clue how they would sound in the MWDR. I would ask in the forums for power tube suggestion. If you opt for the STR445 (what is used in the current production MWDR). Red or yellow would be your best bet. Anything beyond that will just get muddier than the yellow. The STR445 tube is a bit rich on the early distortion factor.

I’ll wait to hear what you think of the 448, the fact I’m always trying to tame the brightness between the head and the v30s… from descriptions, reading and chatting with ai seems like 443 or 448 would be best suited for me… 445’s are jj, I really didn’t like the jj el34’s I tried at all, what I’ve read the 445 6l6 jj can be harsh too like these el34s I got from Eurotubes.

 

[Dreamin90s]

AI is completely wrong. I doubt it can tell the difference or play the guitar. I have the STR440 in every color. STR448 in red and grey. Red has more headroom grey has more early distortion. Plus, I can hear it and tell the difference. An artificial intelligence algorithm only seeks data and may use incorrect information. I would not trust AI for anything at this level of its development. If it can evolve and pick up a guitar, plug it in and power up a tube amp with the tubes in question and play and listen to the difference and then change the tubes and repeat. Then I may accept some of that information may be credible. Sorry, letting AI make your decisions is not a good idea. The last time I checked, I am human.

Oh I am not letting AI make any decesions, it just seems to be a huge Google database at this point.kinda fun to see what it spits out. That’s why I am here on these forums, looking for folks that have experience.

 

[bandit2013]

I see.
The 443 tubes will not have the same fizz and the 448 will be a bit more flat. If you can wait until Saturday, I can run the 443 (grey) and then 448 (red) to see what I think with the MWDR. Normally when I get new tubes I usually run them in several of the amps to see how I like or dislike them. As of late I have been focused on the Reissue IIC+, JP2C and the Mark VII.

First hand experience with the STR448, I got them in grey to match what I had with the JP2C which originally came with the STR440 (grey) tubes. The JP rips with the STR440 but developed some static pops. Shortly after that I got the MWDR. That too had the STR440 (grey). MWDR is a bit brighter than say the Roadster as that was the only reference of Dual Rectifier I have. Totally different amp and that one sounded best with the STR440 red or STR440 yellow. Any how after finding the STR448 grey to be half decent (almost as good as the NOS STR415 I got at the same time) with the JP2C. I tried them in the Badlander 100W and the grey codes were awesome. Bought a second set so I could run them in the other Badlander 100W as I run that amp as a stereo pair. Well, that second set came in red. I tried them in the Badlander and it went totally lame. No drive or punch gain like I got with the STR448 grey. I tried them in the JP2C and that too was lame. No distortion or reduction of total distortion as both amps rely on power tube distoriton as well as that from the preamp. I do recall running the STR448 grey in the MWDR, it was mud fest. Too much distortion and not quite usable. Same with the Roadster. So why the STR440 grey works better than the STR448, it is more or less the difference in impedance as the tubes do have different sound qualities. Yellows in the STR445 are the highest headroom of that tube I have, too much for the MWDR. I will see how the STR443 tubes in grey compare to the STR448 in red with the MWDR. The STR448 red were a bit over the top with the Roadster. Many claim the 6L6 tubes in the dual rectifier are basically coasting at a cold bias. I beg to differ. Dual Rectifiers will have a higher plate voltage and will use the same output transformer as the Mark V90. Same bias voltage as it seems the -51V is Mesa's universal voltage for bias of 6L6 tubes. Since the tubes are different the STR443 in grey may be equivalent to the STR448 in red. That is just an observation.

I will check the STR443 vs the STR448 and see how it pans out. Will also revisit the STR445 yellow again. The STR445 are the stock tubes in the Mark VII and the Reissue, they sound great in those amps. Tried them in the Mark V90 and they did not work out, they sounded terrible.

Trying to reduce the brightness of the MWDR may not be power tube related. More so, the phase inverter tube. A Mullard 12AX7 long plate reissue will add in some bottom end and shave some of the top end a bit. Sovtek LPS will have a weaker midrange content but is the same tube visually. Those are the common tubes used in phase inverters when most start tube rolling.
Mullard CV4004 is also a dark tube, similar in design to the Tung Sol 12AX7 but different tone. The Mesa branded JJ ECC83s is also a dark tube but not quite the same as the CV4004. CV just means Civilian vs Military and the 4004 is the designation of the 12AX7 much like the 12AX7 is also a 7025.

The key tube locations to keep Mesa tubes is V3 and V4 as I stated previously. I have not done much with the MWDR with different tubes so I can see how things turn out. Usually when changing to a different power tube, I will also tune the preamp with different tubes to see if there is any improvement. I will not use any NOS tubes so they will be current production which is easier when it comes time to replace them.

Another alternative is the Tung Sol 7581A. It is Russian but had some good qualities in the Roadster as well as the Mark V90. I still have them, will give them a try but they are not Mesa branded tubes. I bought them from Canada (the tube store) but Tube Depot is in US and they have most of the same tubes.