JAN-GE 5751 in MarkV Head

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a couple of days ago i got a 1961 JHS sylvania 12ax7wa
sounds fantastic in V2...very quiet tube..with excellent bass response..not as "crunchy" as the JJ (117/118)i had in there....
but still get a good heavy tone without the piercing highs..just a great sounding tube overall.
so now im on the search to get a few more sylvania NOS or used tubes.....to try in V1
 
There are so many choices, what is great about the Mark V is that you can tailor the tone with the preamp tubes. When compared to the Mark IV, there are not many options since most of the gain circuits share the same tube as the reverb and other driver circuits. I have not been successful in rolling the IV. What sounds great for the clean channel hurts the lead and channel 2. I am considering another tube roll for the V. This time I will start with all TS V1-V7, and roll in V1, V2, V3. Since the GT6L6-R2's are settling in, it is time to adjust the preamp once again. This time I will pull the reverb tank with the amp chassis. I usually just pull the chassis out and set it on top of the cab (upside down). That way I do not have to wait for the power tubes to cool down to change preamp tubes. I do not mind removing the chassis, however, the cut-out mod on the front panel seems like an option that may be something to consider.
 
if i had the head unit i would probably do the front cutout...
looking to get more NOS tubes soon.....im liking that we can tailor the tone with the preamp section..so im looking at amperex and old mullards
they supposedly have a warmer tone than the sylvanias,,,,,but so far i like the JHS sylvania in V2
i was watching a 6L6 shootout on youtube yesterday and the guy had sed-c- and JJ6L6 and the tone between them was very similar..
the JJs might even had a very slight more bottom end than the sed......ill try to find that link and put in an edit on this post...
the guy also does 12ax7 shootouts too and they are very cool to listen to....
if i get a set of the JJs im going to get a set of rubys from doug...have fun with your new roll and definately let me know what you come up with
 
I was going to begin, but started playing through the amp and decided to hold off on rolling tubes. I like what I have in there now. One interesting thing I noticed is that the Mark V chassis appears to be the same size as the Mark IV. Very similar dimensions, mounting screw locations are the same. The only difference is the transformer support is absent in the IV shell. I will not attempt to transplant the amps, although it is tempting to see if it fits.

I am considering another half stack but may opt for a different brand, perhaps a Carvin V3 which is half the cost of the Mark V head by itself. Hands down, the Mark V has become my favorite amp. I thought about a Mark V combo, if I go that route I will sell the Mark IV.

My last tube roll resulted in the following:
V1 EH
V2 JJ HG
V3 Ruby HG
V4 EH
V5 EH
V6 EH
V7 ST LPS

The Tung Sol in V1 was nice, but was not quite what I wanted. It enhanced the bass response a bit more than I needed.
I may open up the Mark IV and use it as a preamp tube tester to weed out the spent tubes. I would rather get something else such as the VT1000 but so far not for sale yet.
 
the VT1000 looks like a nice unit for the price...i guess all we need to see anyway is if a tube is good or not...
i been looking at hickok 539 testers but right now there are only 2 on ebay and way tooo expensive...
speaking of expensive th aplitrex 1000 is 2600.00 but it does everything and then some,,but i cant justify spending that kind of money
unless i get into selling tubes....by the way i just scored a jhs sylvania 12ax7 and a jan ge 12ax7wa..going to try each of these in V1 and see how these old tubes compare to the new stuff..i also have my eye on a couple of raytheon black plate tubes,,that should be interesting......
i think im getting addicted to NOS :?
if money is not an issue id go for another MKV combo with a totally different speaker....
also looking at other cabs that do not have v30s in it...
your tube roll looks interesting and bet it sounds great.....i like the tung sol in V1..but that 5751 is still in there!!
 
I can think of a better tube tester for $2600, I could get another Mark V and more tubes. :mrgreen: That way you will get more use out of it....

Last night, at it again. This time I wanted to give the "ALL TS" another try. I used that as the starting point. This time I adjusted tone, gain, and everything else in between to get a good overall assessment a fully loaded TS preamp. My first analogy was a room full of old ladies at a PTA conference, that was not accurate. Overall character was not that bad. I played for a while sans reverb in all power modes including variac and full power. If I did not have any other tubes to jam into the holes I would be okay with that arrangement. However, not the case here. Having all TS as a point of reference, I proceeded to roll in the small bottles one at a time. This time I started with V7. Sovtech LPS was the winner. Next came V1 and this time I pulled the old box of spent Mesa 12ax7 tubes with the mortar board getter (old surplus from the Mark III). Holy S**T, they still work, I tried all the other flavors of bobbins in each of the holes and found the Square getter 12ax7 Chinese tubes to be the winner. I actually liked them better than the JJ and Ruby in V2 and V3. So now I am enjoying the following:
V1-V6 Mesa 7025 / 12AX7 (EEC83). Gain of each tube unknown.
V7 Sovtech LPS

The amp sounded even better with the reverb ! CH2 crunch moved up a notch similar to the Mark IV setting on CH3. It still has its character tone as a Marshall clone. The Mark1 setting never sounded better in my opinion. CH3 was also improved to some degree. Similar in character with a 5751 at the front end but not as bright but still has enough grit to put a smile on your face. CH1 was a bit more fluid just the way I like it. At least I am getting use out of the tubes for the time being. I have plenty more of these and may try them out in the Mark IV.
 
bandit2013 said:
I can think of a better tube tester for $2600, I could get another Mark V and more tubes. :mrgreen: That way you will get more use out of it....

Last night, at it again. This time I wanted to give the "ALL TS" another try. I used that as the starting point. This time I adjusted tone, gain, and everything else in between to get a good overall assessment a fully loaded TS preamp. My first analogy was a room full of old ladies at a PTA conference, that was not accurate. Overall character was not that bad. I played for a while sans reverb in all power modes including variac and full power. If I did not have any other tubes to jam into the holes I would be okay with that arrangement. However, not the case here. Having all TS as a point of reference, I proceeded to roll in the small bottles one at a time. This time I started with V7. Sovtech LPS was the winner. Next came V1 and this time I pulled the old box of spent Mesa 12ax7 tubes with the mortar board getter (old surplus from the Mark III). Holy S**T, they still work, I tried all the other flavors of bobbins in each of the holes and found the Square getter 12ax7 Chinese tubes to be the winner. I actually liked them better than the JJ and Ruby in V2 and V3. So now I am enjoying the following:
V1-V6 Mesa 7025 / 12AX7 (EEC83). Gain of each tube unknown.
V7 Sovtech LPS

The amp sounded even better with the reverb ! CH2 crunch moved up a notch similar to the Mark IV setting on CH3. It still has its character tone as a Marshall clone. The Mark1 setting never sounded better in my opinion. CH3 was also improved to some degree. Similar in character with a 5751 at the front end but not as bright but still has enough grit to put a smile on your face. CH1 was a bit more fluid just the way I like it. At least I am getting use out of the tubes for the time being. I have plenty more of these and may try them out in the Mark IV.
wow bandit...go figure that the porly reviewed chinese tubes sound really good,,i was one not to dismiss them in the first place...as a matter of fact i bought two of them a couple of weeks ago...both were in mesa boxes and one was unbranded...the guy i got them from used to know someone at mesa...
he also sent me a unbranded 12AT7(chinese) and a tungsram 12AX7.....plus i still have the tubes that came in my triaxis (all chinese...
pretty funny though that after all the rolls we are doing that LPS stays in V7........glad you found a great tone....
for now im keeping my current setup(with the JHS sylvania 1965 in v2)untill i get different power tubes.....ruby JJs or sed c.....the rubys soun similar to the sed in the low end area.... :)
and your absolutely right if i would spend that kind of money on a tester it would be another MKV :wink:
 
I only had three of the Chinese Mesa tubes left. I wanted to try them out in the Mark IV. Took the one TS that had matched triodes for V5, V1 took on the JJ HG 12ax7 from Doug's cocktail, and I pushed in mesa tubes into V2-V4. Sweet Mole-*****, the amp never sounded better. I had the original Mesa tubes from the Mark V and the Chinese tubes sounded killer. Of course the JJ tube is Russian. I took a closer look at the current Mesa tubes, they look similar to JJ but are not the same tube, I had thought that the old Mesa tubes with the square getter were spent. Some of them were the originals that came in the Mark III.

After rolling the Mark IV, I just could not stop playing. I was amazed that there was new life in CH2 (which in most cases was not all that desirable in the Mark series with exception to the Mark V).

I am glad that I kept the old preamp tubes. I knew most of them would be in good shape since I replaced them every time I changed power tube during the old band days. The Mark III was a kick-ass little amp.

I was actually considering pulling the C90 out of the IV and installing one of the V30's. For those who like their V30's,... never mind. I do not want to start a speaker war. I cannot say there was a change in tone between the EVM12L and the V30's, but there was a considerable difference in performance. I have found it very hard to break the EVM, where as the V30's began to drop out early. In 10W mode they sounded good, but in 45W or 90W the sounded like crap unless you played at bedroom levels. That is probably why I did not use the cab all that much. Even the C90 has its limits, but it sounded better than the EV in the open back small box at low to moderate volumes.
 
thats funny you mentioned that the chinese tubes sounded fuzzy,,,,,,i put a couple in my triaxis and it sounded like crap...
glad i didnt put them in the V.......yesterday i put a jhs sylvania in V1 and a jan ge in V2 of the triaxis and it sounded totally amazing...
today i got a baldwin labeled rca black plate..so that will go in the tri this weekend to test out...so i turned my triaxis into a tube tester for now...
then i will try the tubes in the V.....i have 7 more nos tubes coming this week 2 baldwin sylvania ,2 jan sylvania,,2jan phillips and a rca jrc black blate..all with matching date codes...
currently i have a jhs sylvania in V2 in the mkv and is really good sounding....these old tubes dont have that blaring high end sound to them...but rather a smoother top end..cant wait to try the others in the v as well.....eventually i would like to have all NOS tubes in the V...should be most interesting... :)
i also am trying the tubes in the ADA mp1,,but that unit is a little noisy,,,so i can at least test the tubes for microphonics giving them a slight wack with my finger... :oops:
 
The NOS tubes are a bit costly for my budget. I took a gamble with the JAN GE 5751 as I was uncertain what the end results was going to be. It was satisfying so it was worth the extra coin. This weekend I am going to roll again. I think the Chinese tubes sounded better than what I currently have now. Perhaps a new twist in the mix may be in order. The SED wngC are at their peak and now I have more bass than desired. This time I will not rush to put the amp back into the shell. Also will be removing the reverb tank so I can keep that in the tube roll. Neat trick for those who have removed the reverb tank and are having difficulty returning where it should be. Use toothpick with the fancy plastic on the one end. Insert the tooth pick (with plastic curls) into the mounting holes of the amp shell. Stack the bushings hard plastic nylon followed by the silicone one onto the tooth picks. Carefully place the reverb tank over the ends of the toothpicks. Remove one of the tooth picks and insert the mounting screw and repeat until all of the screws are inserted. This keeps the bushings in their place during assembly. Another option would be to install longer screws from the bottom of the shell, install bushings and tank, then use wing nuts to secure into place. I am really considering inverting the tank (mount it from the bottom of the shell) but have not found a means to suspend it yet.

There is merit for the NOS tubes. Construction materials and assembly process was properly controlled which would result in a better sounding tube. Change in resources (new ownership, transplanted assembly, etc.. ) has left the tube market relatively thin. They can replicate tubes of yesterday, but to fabricate the tube assembly and to properly vacuum the bottle and burn off contaminants is an art form that is not easily replicated.
 
Should have called this thread tube rolling,,,,

Yesterday at lunch time I rolled yet again, why? It takes a few days or weeks to adjust to the new sounds after changing the tubes... Sometimes I like it, sometimes I don't. I have utilized just about every tube in my inventory without the expense of buying more tubes. So far my favorites have become the EH 12ax7 tubes. The JAN-GE 5751 was a solution to cure high frequency tone and to improve use of gain control and presence control of each of the channels on the Mark V, this was especially needed when the final output stage had power tubes that enhanced the high frequencies such as the stock Mesa 6L6GC STR440. I have experimented with a few power tubes not by choice, Two of the Original power tubes red plated prematurely. This was a brand new, never used Mark V! Followed by the used Mesa 6L6GC STR420, which had 13 years on them. I borrowed them from the Mark IV, since I knew they were functional, never had issues with them and wanted to at least determine if there were issues with the MKV that needed to be addressed. At that point, I still had the original V30's in the cab which were just as old as the STR420's but with not much use on them. Since I had always preferred EVM's, I had longed for an excuse to replace the V30's. Since then, I also moved to a Tung Sol 7581 Quad. I also started with Doug's 7 tube tone cocktail. Too bright even with the EV's, uncontrollable tone controls, gain settings were useless, etc.... Had the same issue with the original Mesa tubes too. At that point I was not very pleased with the Mark V, but I was not going to give up. That is where the JAN-GE 5751 came in which truly made a difference. Also to point out, the amp was not broken in (typical drift on components due to thermal conditioning also known as degradation). The same applies to tubes, tone character will change due to erosion of the cathode coating. (continued)
 
(continued from previous post)

Now with different power tubes, GT6L6GC-R2 (relabeled SED wing =C=), the tone of the Mark V is quite different. My recent roll has resulted with the tried but true Sovetek LPS for PI (v7). V2-V6 are all EH, and V1 is the HG Ruby tube. This combination has provided the best performance in all channels, power modes, and both hard bypass and active Loop. I found the HG JJ tube sounded similar to the old Mesa 12ax7 tubes (fizzy). I really like to use CH2 for classic rock and the JAN-GE 5751 just did not work well. However it was not disappointing for CH1 or CH3. Right now, CH2 crunch with gain at 12o'clock puts the Mark IV lead channel to shame (in reference to MKIV combo lead channel in pentode mode.)

CH3 is just full of sustain to the point you get lost into another dimension. Talking about dimension, the amp in all channels has taken on a 3D soul. I have used other preamp tubes and power tube combinations that just did not have that effect. I believe the relabeled SED's contribute greatly to that effect as well as the EV's. I know what you are missing for those who swear up and down that the V30's can't be beat.
 
bandit2013 said:
...GT6L6GC-R2 (relabeled SED wing =C=), ...

:?

Where do you get that info? New Svetlanas are not Winged Cs, and I don't think that GT has used Winged Cs.
 
tonedragon said:
stokes said:
I've been using one in V1 and V3 on my IIC+ for years,really "thickens" up the overdrive,makes it smoother,creamier.Great tube.


When you say smoother n creamer would you say like a soldano? Im hell bent on getting a SLO tone on my Mark v. Im close but not happy yet. I want to retire the soldano from the punishing world of gigs.

The Groove tubes that I have are NOS relabeled SED's. I purchased them through Doug's Tubes as a matched Quad. He recommended these to me since he had one set of quads that would work well in a Mesa. The correct part number GT6L6R-2. I copied the email he sent me:

"Hi Eric,
You order 2 x matched pairs of the winged =C= 6L6GC's. What amp(s) are these being installed in?
We have no SED quads left and the two pairs we have are not close in idle current.

The only other option if you need a quad is we have two matched quads of old winged =C= relabeled by Groove Tubes, the GT6L6R2.

Please advise,
Doug"


The tubes do match the construction of wing=c= since I checked them after receiving. So far it is the best power tube I have yet to experience.
 
wow we are up to 7 pages in this thread....i see youve been buisy :wink:
well i blame my nos tube infatuation on the 5751 jan phillips and never looked back...
since then ive done soo much research(one of the reasons why i havent been here the past few days)
im seriously considering a tester in the future.......while yes it is costly but there are good bargains out there if you buy them in pairs...
then depending on your ending bid sometimes i get away with only paying 20 bucks per tube...the only thing holding back my tone is the power tubes...
i will opt and take a chance on sed-c- and or ruby branded or groove tube branded JJ 6L6s.......JJs have a similar bottom end to the tone like the sed tubes..

as you said on the merits of the old tubes,,they are made soo much differently than todays tubes,,,and so far they sound really good.in my triaxis....
i will be doing extensive rolls in the mark V very soon......so far i really like the sylvania tubes,,,they dont have the grainy harsh tone as the newer JJ tubes at all...so far im up to 15 tubes i purchased in the last couple of months....there are so many to choose from and they all sound different....
but i will say the LPS is still the winner for v7 at the moment.........i have my eye on a raytheon black plate balanced tube i want to try in v7.....weel see!!!

you are lucky to get the last set of GT6L6R-2s from dougs :)
i may get them from tubedepot or get the JJs,,,,,,and i forgot about the tungsol 6L6GC-STR,,,maybe!!
 
What is that saying? I think Tom Hanks summed it up in one of his movie rolls, but twisted in a different verse sounds something like this " Tubes are like a box of chocolates, you will never know what you have until you put it in your amp"
 
shimmilou said:
I'd like to see a picture of those. :wink:

http://s1272.photobucket.com/user/bandit2013/media/P5170092_zps141b14a7.jpg.html

This is one picture I took while tube rolling. I did not get a close up of the Tubes, the twin getter was at an angle so it is hard to see if at all possible.

The engineers, workers, etc that used to sell under the Svetlana banner formed the company SED after New Sensor bought out the rights to sell under the brand name Svetlana. Before this, 6L6GC wing = C= was manufactured by the company in St. Petersburg that sold under the banner of Svetlana, then they became known as SED. I am not sure when this occurred. The GT tubes I have were made prior to 1990. I had called Doug and talked to him on the phone before buying the tubes. If I remember correctly he said they were from the early to mid 80's. Groove Tubes are like Mesa and others that buy tubes from various vendors, test and sort them based on characteristics and also stamp their logo onto the tube. The r2's are from the gold series. Going to the GT website, does not list these tubes. They are old stock and may be available in distribution.

SED's are still manufactured, however, they lost the ability to sell in the USA. Visit the SED website for more info.
 
Great picture, thank you very much! They sure look like Winged C alright.

Being a GT fan, I noted on their previous site that the R2 was also from the Russian Reflector plant, just like the R1 which is Sovtek. I know that now, R2 indicates the Reflector plant produced tubes. The Reflector plant is my favorite for new production tubes, including Sovtek, EH, Tung Sol, Mullard reissue, Svetlana, and Mil-Spec tubes. It used to be harder to know where GT tubes were made, but now it's pretty straight forward. The -R are from the Reflector factory (Russia), the -C are Chinese (Shuguang I believe), the -S are Slovakian (JJ factory, made specifically for GT, not relabeled), the -M are Mullard reissue, as well as some other exclusive types made specifically for, or by GT. For a short time, from 2008, the GE reissue were made in USA, but I think that they have moved production to China now.

Thanks again for the info, I sure would like to find some of the GT labeled Winged C, they are great tubes. For now I'll have to be happy with my regular Winged C.
 
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