RFTs in Mark III

[Facelift]

I changed out the stock Mesa tubes in V1 and V3 of my Mark III blue stripe and the tone change I noticed was immediate. While the stock tubes made it sound great, the amp sounded real bright no matter what way I eq'd it. When I put the RFTs in I didnt realize that the knobs I normally have pulled (pull shift) and (Pull Deep) were pushed in, and it sounded even better. When I noticed I didnt have em pulled I of course pulled them and WOW, what a difference Pull Deep makes now. My first reaction when i did the palm muted E chord that a plane flew by and created a sonic boom. :lol:

The RFTs took the bright character of the amp and smoothed it out while of course making it darker. It seems to have ALOT more low end, more bite, and overall a more 3-D sound with much more clear notes being heard in chords. It was suggested by a member here that i try the RFTs (thanks Neptical) becasue of the style of music I play (heavy thrash). Anyway, I couldnt be more happy to have spent the money on the RFTs. They gave me EXACTLY the sound i was looking for which can only be described as "the broOtals" or 'fire breathing dragon". Surprisingly enough, the clean channel still sounds good, actually better, rounder, fuller, creamy and rich. What more could you possibly ask for?

Only thing I can say is if "metal" is your forte then the RFT ecc83s are the tube to put in the Mark III.

Currently the tubes i have in the sockets are as follows.

V1 - RFT ecc83
V2 - stock mesa 12ax7
V3 - RFT ecc83
V4 - stock mesa 12ax7
V5 - JJ 12ax7

Im debating on changing out the three remaining sockets with all RFTs. Not sure if thats what I want to do though. I dont use reverb so Im thinking the extra money spent on replacing V4 with an RFT may be pointless. Sometimes I like to blend R2 and hte lead channel for some real heavy distortion and considering what the RFT did for the lead channel, this may be the way to go. I dont normally use R2 by itself so a different flavor isnt really something I require. As for the PI tube, Im really not sure about what should be in there but the guy i bought it from suggested I keep the JJ in the PI. What do you guys think?

 

[94Tremoverb]

I think RFTs are some of the best and most under-rated 12AX7s ever made, they will fatten up any amp that's a little too bright and edgy (like a 70s Marshall) perfectly - I totally agree they seem to have more bottom end, more harmonic distortion, and a really nice biting (but not harsh) top end. I also love the rich, warm cleans they give. For such a great-sounding tube, they're not even expensive - I would put another in V2 anyway, also probably in V5, but I would put a 12AT7 in V4, they work better as reverb drivers... a JAN/Philips is about the best of the bunch for tone and reliability and also not expensive or difficult to get.

For what it's worth, RFTs were stock in Marshalls during the mid 70s, and I wonder if the increasing brightness of the amps was partly deliberate to compensate, or just the way they were going anyway and the combination is just a happy accident - either way, those amps still sound best with them in my opinion. I really must get around to trying a full set in my Tremoverb...

 

[212Mavguy]

I really like the RFT as well for all the aforementioned reasons, love the warm cleans as well. One thing not yet mentioned is that they are among the most resistant 12ax7's to microphonics. A tube cocktail of RFT, Siemens shortplate, and Amperex shortplate arranged to personal taste will take that Tremoverb to places it has not yet been in a very good way.

 

[Facelift]

Anyone have any experience with the RFT EL34? Would they be comparable to the Mesa EL34s amd would it be any benefit to swap them? Seems alot like the str-415 6l6s but I dont see much about the el34 preference. Looks like the RFT el34 is pretty expensive as well so just wondering if it would be worth it and what to expect from it.

 

[212Mavguy]

RFT power tubes are really, really great sounding. Their el84's are bad to the bone. RFT made some el34's for the Siemens label. Siemens el34's that had the mesa label were some of the the best sounding el34's Mesa ever had. You might run into bias issues with el34's that don't have Mesa labeling. All the more reason to put in an adjustable bias system. I think that some of the most rabid Winged C el34 fans would be pleasantly surprised by the richness in the sound of some RFT el34's biased right into their sweet spot. The RFT's will last longer as a rule, too.

 

[boogietone]

In regards to the RFT/Siemens EL34's, I'm looking to replace my power tubes with either those or JJ KT77's.
Would there be a very noticeable difference in bottom end between the KT77's and the NOS EL34's? I'd
like more bottom end, especially for the cleans but would really rather go NOS power tubes. Any thoughts?
Sorry for the hijack.

 

[212Mavguy]

You probably won't like my answer, but here goes anyway for my $.02...

No compromises for your tones!

I'd Stick the RFT's in there, pick up a couple other vintage el34 pairs/brands like Amperex, Mullard, Tesla, or some Sylvania fatboy 6ca7's and get an adjustable bias mod put in. There's more to like about your new tones as a result than going the more conservative route of using new production tubes, even though the JJ kt77's have a good tone rep in many applications. Then if you want you can voice the amp for a specific guitar or venue should you feel like getting that picky.

 

[Facelift]

Thing is is I dont know what to check on tubes thier sockets or whatever to know what the bias should be set at if I were to get the bias mod, and I wouldnt want to take it in each time I change tubes. Definitely something I want to know how to do on my own.

I am also looking for just a bit more bottom end. I already have a pq4 and a flanger/doubler hooked up to the mark III. I can say it "almost" matches what the Warhead X2 puts out for bottom end chunk. Considering what hte ecc83s did, surely the RFT el34s would help. The nos RFT tubes really have a smoother sound to em. I had heard that hte JJ e34ls are great for this too but still, I think I wantto try out the nos but yet again, I know nothing of bias mods. Guess I could have it sent to Mike B. at Mesa but I just dont want it to make it a pain in the *** down the road.

 

[212Mavguy]

Another way to go about this is if you know a Mesa Certified tech and have him do the job, tell him what you need to know about doing up the bias thang. Best situation is if he is local or close enough by so you don't have to ship the amp, and you can sit next to the bench and have things explained to you in person, that's what I did. Several of my non mesa amps are adjustable for bias and even bias balance between the pair of power tubes. Where necessary, I keep a piece of paper with notes handy within the headshell or cabinet for each amp. Once you get the knowledge, you will be far better off tonewise...I just had a bias mod installed in my Maverick and it has never sounded better. Easy as pie to adjust in the way mine was done up, ingenious tech I have! See "Sick Maverick ;(" in modern amps here.

A mesa factory guy like Bendinelli might be more than a bit reluctant to install a bias mod in one of their amps, mesa as a philosophy designs amps to not be user adjustable in the bias department. good luck!