Best Power Tubes for Mesa Boogie MK IV ?

[CU2487]

Hi all,

since some time now I´m quite happy with a quartett of STR 425 / 5881 - 6L6 from Mesa in my MK IV combo. A long time before I used the stock Chinese 6L6 STR 420, and I wasn´t so happy with their clean sounds, later also several pairs with different color codes of the Russian STR 6L6 430 from Mesa, which were much better and a good all rounder for my personal taste , further more also the Svetlana 6L6 STR 454, which had the best clean sound in my opinion. Tried also a pair EL 34 in the outer tube sockets, but this wasn´t my cup of tea. I guess, I´m more a 6L6 tube type fan, at least with my MK IV. I really like the 5881 the best at time, very warm, round punchy sound with good defination and not too midrangy. What do you MK IV user think, any further recommendations?

Thanks in advance :)

Regards Arno

[green]

I use the 5881 and the tesla e34ls (groove tubes) in my mark 3.........I was using 5881's in all four, but I really like the e34ls........that and they last alot longer in class a......almost 3x's longer and still going.........on that note, I 've been wanting to check out the str 454 myself

[irwcustom]

I use a MK3 with a quartet of matched Groove tubes 6l6GC's. I'm not saying they are the best. They are definately better than the ones that came with the amp which were 2 6l6's and the El34's. You probably know about the grading system. Well, I have a set of #8's. They sound great to me in my Boogie.

I have a '65 twin and this was bias set up to run a set of GT #7's (performance matching). Obviously, the performance matching does not determine bias setting I have found out. 3 of the four tubes I had in the twin got smasheb in transit. So I thought the #8's would be a good close match to the old set that was in the twin. Just to try them, I borrowed them from the Boogie as my mate wanted to hear the twin. The #8's glowed red in a fairly short space of time .. and we're talking hot - as I was distracted at the time and wasn't keeping an eye on what was going on. They sounded great straight away and I initilally though I might get away without a bias adjustment. I found a more suitable match - perfect for the twin - you don't need a matched quartet in a push-pull amp - in the Fenders case it's the two outer tubes and two inner ones as a pair of matched pairs - not necessarily quartet - though if you can all well and good. Anyway, tested for shorts and anything untoward and put them back in the Boogie. Absolutely perfect still - must say something for them though you could be forgiven for thinking that the #8's would be fairly close to the #7's. (Graded from 1 to 10 - 1 breaks up earliest - in case you don't know.) They've lasted me about 10 years so far. My Philips ones are also great, but I'm saving them. Haven't tried anything else.

[green]

what model 6l6 are they? who actually makes them?

[irwcustom]

Groove tubes 6l6B iswhat's written on the tube - valve. H8 ECB on the sticker. Sylmar California. 6l6 GC is the normal teminology. GC stands for glass container.

[CU2487]

Hi, yes I know the GT Power Tube Ratings and as far as I know, GT recomments the 4-7 (White) range for Mesa Boogie amps. I could read already good reviews about the GT tube in generell, especially about their 6L6-GE. I just found an older interesting threat named "suggest tubes for me" in the Mesa Boogie Forum under the rubric Mark Series Amps, which I joined for a long time, until I became aware, that the administrator unfortunately seems to be also the admin of a nazi forum. Too sad, because actually a very good forum, which I liked a lot.

Nevertheless for your information here the link to the above mentioned threat:

http://pub61.ezboard.com/fmesaboogieampforum77319frm7.showMessage?topicID=5 69.topic

Especially the experiences / opinions of Boogie Babies is ver interesting, IMO!

Until later :)

Arno

[irwcustom]

Thanks for the link Arno; never heard of that site. Sounds like it's a good job they don't have an 'other interests' section!


I have the Aspen Pitman tube amp book but can't at the moment find the 4 to 7 reference. It does seem to ring a bell with me though. I can verify that an 8 will be fine for you if you like Fender sparkly clean with not a harsh lead tone. Go for a straight tube if you can - the stepped ones are Chinese - I'm not sure if this is exclusively true in all case though. I have a pair of Ruby tubes (these are stepped bottle ones and Chinese) and 2 messas in one of my '65 twins. This sounds great I must say - but I was just after something that worked for now.

The Boogies are great work horses. i plugged mine through a '68 red Marshall 4 x 12 red PA cab with 4 Green backs in - measured 10 ohms resistance (not impedance). No problems what so ever and it sounded superb on lead tones. Built to last!

[CU2487]

Hi, you are right, you don´t find the Mesa Boogie reference scale in the Aspen Pittman Tube Amp Book, which I also have. Also at the GT- site, one can´t read something about that. It´s already some time ago, I found the following link, with a lot of interesting technical information about Groove Tubes, also detailed information about their power tube rating system. According to their explainings, the GT- range for Mesa Boogie amps is 4,5,6 as following:

Mesa scale / Groove Tubes scale

Red / 4
Yellow / 4
Green / 5
Gray / 5
Blue / 6
White / 6

Here is the link:

http://www.guitaramplifierblueprinting.com/groovetubes.html

However, the interesting point is, that mesa boogie himself says, that their is no relationship to the idle current draw of their tubes and their color coding. Which means, that for example a red colored power tube don´t run hotter than green or blue colored one´s. According to Mesa Boogie, their color coding is for matching, selecting purposes only.

2 years ago, I bought a bias meter (bias master from ruby tubes ) and did just for interest some measurings of the idle bias current with different colore tube pairs from Mesa and my Mark IV. To make it short, the measured idle bias current values I could read were surprisingly low, much lower as expected, also regarding the oftener mentioned medium bias current draw of Mesa Boogie power tubes, which should be around 30 mA with a 6L6 tube for example. At least I had expected readings around 25 mA for a 6L6.
A further interesting result were greater different idle current values than expected, regarding what Mesa told me about their color coding system. I had pairs of Mesa´s 6L6 STR 430 with green, gray and blue color codes. The funny thing was, that I could read only between 11 to 17 mA, apperently rising from green to blue. that would be just what the GT scale says, but in reverse.
I did all measurings with the inner tube pair of the MK IV, running in class A/B using the Tweed Power modus, which I mostly like to use. I just tested the whole thing also in the Full Power modus and the idle current values were growing around 4 to 6 mA. Still quite low, IMO!
Although with a pair of 6L6 STR 454 ( Svets ) I got around 25 mA with Tweed Power and 33 mA with Full Power, what should be oK.
To avoid misunderstandings, I´m still a great fan of Mesa Boogie amps and also their Fixed Bias concept or philosophi. I had never any problems with their power tubes and got always good sound results, apart from the stock 6L6 STR 420 , my MK IV came with in 1991.
My measuring results do change nothing about that, no flaming against Mesa Boogie. It´s just for technically interest, clearing things and getting more detail information.
A further interesting thing seems to be, that my Mark IV and perhaps also the other Mesa Boogie amps, sounds good also with such fairly low bias idle current values and also not noticable better with higher currents.

Arno

[Layne]

Groove Tubes all the way! That was the first thing I did when I got my triple rectifier - replace the 12AX7's, 6L6's, and 5U4's with Groove Tubes.

Sincerely,

[irwcustom]

Thanks Arno - that confirms it for me that the grading system is independant of the bias setting. Though how they come about the performance matching when all tubes are sets - (or sold as such) and will be biased by one control (naturally) I do not know. I use a mulimeter for my readings, though a bias meter makes life a whole lot easier. but you can't beat your eyes and ears at times for finer adjustments.

[Sherpa]

Hi, you are right, you don´t find the Mesa Boogie reference scale in the Aspen Pittman Tube Amp Book, which I also have. Also at the GT- site, one can´t read something about that. It´s already some time ago, I found the following link, with a lot of interesting technical information about Groove Tubes, also detailed information about their power tube rating system. According to their explainings, the GT- range for Mesa Boogie amps is 4,5,6 as following:

Mesa scale / Groove Tubes scale

Red / 4
Yellow / 4
Green / 5
Gray / 5
Blue / 6
White / 6

Here is the link:

http://www.guitaramplifierblueprinting.com/groovetubes.html

However, the interesting point is, that mesa boogie himself says, that their is no relationship to the idle current draw of their tubes and their color coding. Which means, that for example a red colored power tube don´t run hotter than green or blue colored one´s. According to Mesa Boogie, their color coding is for matching, selecting purposes only.

2 years ago, I bought a bias meter (bias master from ruby tubes ) and did just for interest some measurings of the idle bias current with different colore tube pairs from Mesa and my Mark IV. To make it short, the measured idle bias current values I could read were surprisingly low, much lower as expected, also regarding the oftener mentioned medium bias current draw of Mesa Boogie power tubes, which should be around 30 mA with a 6L6 tube for example. At least I had expected readings around 25 mA for a 6L6.
A further interesting result were greater different idle current values than expected, regarding what Mesa told me about their color coding system. I had pairs of Mesa´s 6L6 STR 430 with green, gray and blue color codes. The funny thing was, that I could read only between 11 to 17 mA, apperently rising from green to blue. that would be just what the GT scale says, but in reverse.
I did all measurings with the inner tube pair of the MK IV, running in class A/B using the Tweed Power modus, which I mostly like to use. I just tested the whole thing also in the Full Power modus and the idle current values were growing around 4 to 6 mA. Still quite low, IMO!
Although with a pair of 6L6 STR 454 ( Svets ) I got around 25 mA with Tweed Power and 33 mA with Full Power, what should be oK.
To avoid misunderstandings, I´m still a great fan of Mesa Boogie amps and also their Fixed Bias concept or philosophi. I had never any problems with their power tubes and got always good sound results, apart from the stock 6L6 STR 420 , my MK IV came with in 1991.
My measuring results do change nothing about that, no flaming against Mesa Boogie. It´s just for technically interest, clearing things and getting more detail information.
A further interesting thing seems to be, that my Mark IV and perhaps also the other Mesa Boogie amps, sounds good also with such fairly low bias idle current values and also not noticable better with higher currents.

ArnoArno, great post - between you and Jim Collins who needs an amp and guitar tech? ;) I've found that the KOCH 1-9 rating system tends to "drift" a bit as well, and find that having the MT re-biased every time I change power tubes is well worth it.

BTW - did you make it over to the Frankfurt MusikMesse this year? If so, how are Dolf and Ullrich Teuffel doing? The last time I went, Ullrich gave me a 45 minute long runthough with a couple of his Birdfish guitars - I've never played an instrument with such incredible attack.

I'll send you an email to avoid hijacking the thread - it's good to see you back.

JP

[CU2487]

Hi JP,

nice to meet you here again. Hope all is well with you and your family. Are you still living in Madrid?

Unfortunately I couldn´t go to the Frankfurt Musik Messe this year. What a bummer, because Paul Reed Smith was there as far as I know, but I had to work this weekend.

I guess, you are still satisfied with your MT. Great tube amp, IMHO ! The only downside with tube amps,.... so many different tube brands available, so many sound nuances, but also the pain of the election. :D
That´s why I startet this thread.
Good to have Tube rating systems which are rather helpfully.
To have a bias control trimmer is surely no disadvantage, very comfortable for every service tech or musicians, who are familiar with the technology of tube amps.
Mesa Boogie has another philosophy, with their Fixed Bias Concept. About this one can argue infinitely. IMO, Mesa´s concept also works as long as one can trust their statements about their tube testing prozedure over all the important tube parameters, not only the idle current draw . At least it´s very comfortable for the user, no bias needed, as long as the used power tubes are in the range of the Mesa amp specs. Low tolerances are fairly normal, no matter which rating system. The stated measurement values are reproducible only under the same measurement and test conditions, the tube seller uses for example. And the operating conditions of our tube amps are so different, beginning with the normal fluctuations of the 230 V AC outlet voltage, which can be - 10 / + 6 % in Germany at time.
And it goes on with all the technically details of our tube amps, the kind of the power tube stage, toleranzes or unbalances of the output tranny or even the phase inverter tube, different modes of the power stage, as it is with the Mark IV ( Simul Class / Class A / Full Power / Tweed Power / Pentode or Triode ) and so on.
But the drifting should be low, as far as the power tubes are sufficient burned in also.

Best regards
Arno