JAN-GE 5751 in MarkV Head

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The new tubes are GT6L6-R2. Groove tubes selected SED winged=C=. They are quite similar to the Mesa 6L6GC STR420 with the exception that the internal orientation is inverted on the STR420's. I thought the 7581 (30W versions) were great before they went flat, the GT6L6-R2 are much better. Nice rich harmonics, great saturation, more bass response than the 7581, more mids, just better tubes in all respects. The next best tone I have discoverd was an integral quad of 6L6GCSTR440 in center and 6L6GCTR420 on the outer positions. (only spares I had available that were not in use). I have found that I needed to drop the bass a bit, not too much but enough to keep the wall onrnaments on the wall. I have also rediscovered that the effects loop alters the tone so I am no longer using it. I can vibrate the house in all modes, that reminds me to remove the casters from the cabinet. The SED's are Awsome ! Groove Tube rating is a 4 on all tubes. As before, I requested tubes for the MARKV from Doug.

The high frequencies are not as harsh as they were. I had a few EH tubes left over when I retubed the Mark IV. All tubes are EH12ax7 and final drive is a quad of Svetlana (new sensor) tubes. Tung Sols are also manufactured by New Sensor. I have been very pleased with the Svetlana 6L6GC in the Mark IV so I thought the Tung Sol 7581 may be a good choice. Hopefully the SED' last a bit longer. I hope they last as long as the original Mesa 6L6GC STR420's I had in my Mark IV (while they were in the IV that is. After 13 years of use in the IV, they did not last very long in the V. I have some NOS STR420's on hand since I bought them as spares when I purchased the MKIV, also a pair of the Original STR440's that were in the outer most sockets that remain undamaged after redplating the inner two. Still unclear on the redplate problem, it has not happend since I rebuilt the 412 cab. More than likely a bad tube.
 
the effects loop definately changes the tone but i find when the solo switch is activated it seems to put back the boost if you will to the circuit....to give back what seemed to be taken out..definately a volume jump for sure.....
if youre not using the loop anymore are you running any effects in the front side of the amp......im not too crazy for the loop either but i wanted to use
my gmajor......it doesnt sound good at all hooking it up to the front of the amp,,,,so i may opt for a strymon timeline to use in front of the amp......delay is really the only effect i like to use when it comes to effects,,sometimes chorus as well........good luck with the winged c tubes......i have a set in my 50/50 so im going to put em in the V.....i really like the low end they produce......i hope i can find a similar brand tube with the same characteristics as the winged c if they are not up to par lately as some say they are!!!
 
I knew I was going to get back to the 5751. Had to play for a while with a differnt tube in V1. The Jan5751 just has gives the amp a bit more definition in the high gain CH3. As soon as the amp cools down, it is going in.

Doug's Tubes still has a few sets of Quad GT6L6-R2. Cost is $180 for the set. My ears are still ringing. They are bright but not harsh, definately more full bodied sound than the 7581's. Holy Hanna, the tubes really rock. Talk about Chuga tubes. I was going to buy these in the first place, but thought get the 7581 and an extra rectifier tube. I ordered the SED's but Doug only had matched pairs, he said they are not quite up to par for a Mesa amp. He did recommend the GT R2's which are old stock SED's.

I have many effects, just do not use them anymore. I like the tone of the amp without anything added. I used to favor my Alesis midiverb 4, but every time I hook it up I spend more time messing with settings than I actually do playing anything. Then there is the Digitech RDS4000 time machine is great too. I can get a chourus sound from that. Both of which I normally used in the effects loop of the Mark IV. The Alesis is having issues and not worth fixing. I also have a Boss ME-70. Sounds great with headphones. Not so great in the effects loop or on the front end of the amp. I use that in the event there is no power and I want to play the electric, makes for a great practice amp. I recently purchased a Line 6 DL4 delay moldeler. That is a very nice effect. It even has a short looper but 15 seconds is not long enough to be useful. I can get a great modulated delay from that. It is much better than the Alesis or the Digitech since they are more than a decade old. When I use the effects I use the loop. All of the pedals I gave away many years ago at the time I never thought I would pick up the guitar again. I screwed up my left hand and a tendon in my elbow a few years ago. I just could not tolerate the pain. It was not until recently that I got back into playing the guitar. I needed to say goodbye to my MKIII properly before I sold it. My wife had also requested that I stay with playing again. Since it has been a release of emotion for me, she knew it would be inportant. She passed away mid November last year as a result of liver and kindey failure. Sometimes life just sucks, she was way to young to die. It was not all of a sudden, She was perfectly healthy when I met her. She was in a car accident 3 days before we got married in 2009. The medications that were administerd for over a year caused irriversable liver damage. While she was in the hospital she wanted me to promis I woudl buy myself something. I bought a new Carvin in her memory. The amp on the other hand I bought because I took out too much money to pay all of the medical bills.
 
first im verry sorry to hear of your wifes passing..and through the music we love and play makes life a little easier...also playing is good therapy for that wrist
i can relate to hand injury as well,,,,would take too long to explain.....any way i was just on dougs website and he has one set of the GT6L6-R2 rated at #7
that my be too hot for the mkv.....
im starting to like the amp without any effects too,,,,boy i wish i could get back all the pedals and gear i sold or gave away,,,i could start my own store...live and learn!!!so i just have the g major and a behringer ultrafex pro..wich i havent used in awhile...
let me know how the 5751 sounds with the sed tubes....
 
I miss my wife greatly, thank you for your sympathy. We had many great times together. I guess I let it slip since I was at a funeral this past Saturday. Best not to focus on that subject.

As for the Jan 5751 with the SED's, well it tamed a little off of the top end which was an improvment, but took more from the bottom than I expected. In the clean channel it has the best effect, Ch 3 not noticable except a drop in Bass. and there was a notable difference in CH2 that I did not notice with the 7581 pushing out the vibes. The SED's opened up a new world of tones, overtones and character from each of my guitars. Either the Winged = C= are heaven sent or risen from hell they just have the sound I was looking for (that is assuming I can still hear). I can understand why many like them. I could live with the 5751 in V1 but the EH12ax7A proveded the deep lows and only capped off the brittle highs just enough that it is tolerable. I was surprised that the EH with 110/115 gain per circuit would be as nice as the 5751. Both tubes do and excellent job in V1.

Not sure about #7's. You would probably have to push the amp to saturate the tube. I guess I got lucky when I ordered them.
 
After leaving the last post I decided once again to pull the chasis and put the 5751 back in. Not really sure what the gain is on the 5751 that I have. It may be higher than the spec (70). It sounds so close to the EH12ax7. The only deviation from Doug's cocktail is V1 (5751), V4 and V5 Tung Sol, V6 EH. The SED's maskarading with GT logo can enhance the preamp tube mix very well. (I would not recommend all Tung Sol's unless you like your flavors on the bland side but they work great in the driver circuits).

Same as before, 5751 adds a different character to overall sound, more defined is a better term. Nice thing, I can get some controllable feedback, play softly into CH3 with moderate gain settings in extreme mode and get a nice glistening clean sound with just a little bite, hit the strings a bit harder and wake up the beast all without having to adjust the volume control on the guitar.
 
I was at it again. I had to hear the difference with the 5751 in the PI location. Perhaps this would be better suited in a different amp as a phase inverter, it worked but I did not care much for the results. In the Mark V, the V1 position is the only option. While I had the chassis out, I pulled all of the preamp tubes and reinstalled the original mesa 12ax7's since they serve as the benchmark for the overall tone. I collected all of the tubes that came with Doug's tone kit. I wanted to hear the difference with different tubes starting with V1. The Penta lab tube sounded okay in V1, same goes for the Tung Sol, but they were lacking something. Having all stock preamp tubes in all positions and rolling V1 the 5751 and the EH12ax7 sounded about the same (final output GT6L6-R2 [SED winged =c=]). THe EH just had a slight edge on gain. The JJ sounded the best in V3 for all channels. The Ruby labeled HG tube is similar to the JJ tube, In the V2 helps to enhance CH2. I left the mesa brand in V4 and V5. V6 was rolled and the EH seemed to offer a good character. Not much noticable difference in the PI spot between sovetek LPS, tung sol, or mesa. I opted to keep the LPS since it is the only tube that has matched triodes. As I mentioned before, the 5751 is better suited in V1 than V7. Perhaps if I had different power tubes, the preamp mix may be different. Everybody will have different likes or dislikes, so what may be appealing to me may not be desirable to others. Three things that make a difference, speakers, power tubes, and last but not least are the guitars I use.

5751 offers clarity and sweet tones in CH1, very nice signing character for CH3 without loss of distortion with a slight reduction in bass and upper frequencies. The EH on the otherhand brings out more edge on CH1, a bit less definition in CH3 with more bass and high frequencies. They are close in tone, and overall sound. If you like playing heavy metal, perhaps the 5751 is not a good match for you. I play many different styles so I find the tube to be suitable. Now I am undecided on 5751 or the EH12ax7 for the V1 tube. Too bad I cannot use both at the same time.
 
very interesting bandit.....i hope this weekend i can get some rolling in to see how the 5751 works in my V.....
my 5751 is rated at 95/95gm balanced.i was curious about the v3 tube i have yet to get a jj in there...
 
If you still have mesa tubes, I believe they are the same as the JJ, either that or they are perfect copies. The HG verisions are not much different in construction. Oddly enough there was a notable tone difference between the two. The Ruby labeled tube is also identical to the mesa tubes. I could probably go throug my boxes to old mesa preamp tubes and compare them to other brands and look for similarities of the internals.
 
i have the stock mesa tubes yet from the V and they are all JJs....yesterday i went through all my older mesa tubes and some are russian 2( EH i think),,and the older mesa tubes that were in my 2:90 are actually mesa branded EI yugoslavia tubes..the spax7astr are also JJs,,i had to pull the rubber sleve off to see what they were,,,,,i also just got a mesa branded NOS chinese tube from ebay,,for some reason two exact same tubes with the same gain readings will sound slightly different,,,,,,i had found that out while tube rolling the triaxis....im getting quite a decent collection of preamp tubes..
did you get a ruby chinese tube in the doug's kit...
 
Both of the HG tubes were from Ruby, one marked as JJ and the other Ruby HG. I believe the internal construction appeared to be the same. The old preamp tubes I pulled from the Mark IV are JJ tubes. I also have several tubes that I pulled from the Mark III that look nothing like any of the other tubes. The plates are not as short as the JJ , not as long as Penta Labs or Sovetek, Spacers are completely round with some round square fermica supports, and to top if off, it has a square getter. All of the pins are connected with wide straps. I would like to get a tube tester to evaluate all of my old tubes.

This is the first amp I have experimented with tube rolling. I know I will never be able to duplicate the Mark IV sound, not really sure that I would want too. I am debating on either keeping the IV or selling it and opt for a select wood V combo. I would not mind having 3 amps. Maybe a roadster combo. I would definately have to re-evaluate the roadster again. I did not like the one I tried out probably because I could not dial in a sound I cared for, the tech was not much help in that regard since he was not familiar with Mesa's (I could not get the mesa guru to help me decide).
 
can you post a pic of the tube from the mk3..they might be chinese tubes..
im thinking of getting a tester for myself but the one i want(maxi preamp tube tester)
is almost a 1000bucks...but i want a tester that shows all the requred data and not if the tube is just good or not
the tester that orange makes is about 500bucks but i dont see it being sold anywhere yet..
i saw a few really nice select wood combos on ebay
 
I've had every type of tube tester under the sun over the years and I can tell you the best tube tester is the amp you will use the tube in,once you are sure there are no shorts.That is about the only reliable test any tube tester can do.I do use a Triplett 3444 these days,but only because I've been amassing old stock tubes for over 25 years and needed to cull some before even putting them in an amp.One example is a pair of RCA 6V6's that were done,low output ,excessive hum but they tested well on all three testers I had at the time,no shorts,excellent gm good emissions and did well on the "life test",if not for the gas test I would still be scratching my head.It failed the gas test.I have over 100 NOS preamp tubes,all test well including gas and shorts,some sound better in some amps and not so good in others.I had a VTV preamp tube tester for a while,one of the top of the line for testing AX7 and such types,my ears were better.Just find a decent gm tester that will show shorts and gas and dont waste the big bucks for Maxi preamp tube tester or such,it will still come down to what sounds and performs in the circuit you use it in.
 
I still have all of the preamp tubes from both MkIII and MKIV. $500 for the GT1000, I was hoping for it to cost a bit less.

I started by Need for more Carvins shortly after I bought my first one. I have my eye on many listed on Ebay, I am considering an LP copy and one or two of the CT models. I have plenty for now, but still have the CGBS bug. I never really suffered from Chronic Amplifier Buying Syndrome. I have only ever owned 6 amps do date. All of the Mesa's outlasted and of course outperformed the others. Fender, Marshall, and some unknown brand. The Mesa MKIII was the only affordable amp that would keep up with the band. That was worth every penny. I lost cound on actual number of guitars I have bought, had some bad ones and really good ones over the years, I do miss my LP. Perhaps I will scan the old pictures I have of it and post them on photobucket.
 
I udated the pictures in the bucket. Go up to the link for the tube.

Limited edition Gibson Custom shop LP 1984 and serial number 009. They are in Black and White. The white guitar next to the LP was a modified Robin with Kahler 2300. The amp in the background is a Fender Deluxe Reverb.
 
5751 update:::first here is the config i put in,,, note;;the eq setting was at the usual V shape!! all channels@90w
V1-jan phillips(95/95)balanced
V2-electro harmonics(110/110b)
V3-JJ(115/116)
V4&V5--tung sol(110/110b)
V6-JJ(115/115)
V7-sovtek lps(115/115b)
my first impression is that the amp had a slight raise in overall volume and brightness i didnt expect.(i did not adjust any settings before this tube roll)


CHANNEL 1 tweed mode sounded really good and clear,,i had dialed back treb,mid,bass to 12 to get a really nice sound,very crisp,,,not much white noise hiss
on that channel...or low level hum.....

CHANNEL 2(crunch+thick)::i do not like the EH tube in channel 2,,took away some bottom end and added a trebly sound i didnt care for,,,,also dialed back on the treble added some mid and bass...couldnt quite dial in a good sound with or without the eq engaged....this channel needs a higher gain tube imo..just lacked definition and that balls to the wall i like in that channel i had with the previous tube setup...

CHANNEL 3(mk4+bright+pentode)the 5751 added a jump in volume despite the lower gain and is a bright tube overall...
i will also say that overall tone in all channels was very clear sounding...no mushy notes...good pick attack.
but just lacked some bottom end that im used to,,,,,however i will say that i reduced the gain knob to 1 oclock and got a decent and better tone.(also reduced the white noise hiss a little)..all the notes are in your face...i do like somewhat the tone i get from the 5751 but i need to find that sweet dial in to get the most out of it.....also the lead tone changed as well (with the eq off)sorta lacked that "petrucci" like sweet tone if you know what i mean!!
the EH in channel 2 will be changed to a JJ high gain......we will see if that changes the overall sound at all...
if i missed something i will add later..
something is making the sound a little too bright so i have to see what i need to switch around...
any suggestions are most certainly welcome :)
bandit your assessment above is right on the money,,,,,i could hear everything you described... :wink:
i like the clarity but also like the brutal tone this amp can achieve.....
 
just put a JJ(117/118)in V2 and sounds great....going to give the 5751 a fair chance to get used too..
so far its ok :!:
 

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