JAN-GE 5751 in MarkV Head

[bandit2013]

For those who suffer the high frequency response being overkill in your amp, in other words; the treble knob on your amp is useless which was the case for my Mark 5, try a JAN-GE or JAN-Phillips 5751 in the V1 socket (the JAN-Phillips was rated a better tube but I could not fine one). You will not loose very much gain since you will only be reducing the input stage and others by 30%. Typical 12ax7 has a gain of 100, 5751 has a gain of 70. In fact the 5751 is a military spec 7025 tube. After rolling the 5751 in other locations I found it performed best in V1. Now I can dial up the gain in CH3 and get some great tones, distortion with definition. Just for kicks, I returned the tube back into V1 to compare, sure enough the 5751 cured my dislike of the Marrk 5. There is only a slight tone change. In fact it is better. Now I can make use of the parametric EQ (treble, mid, bass) and actually hear the difference when adjusting the treble control. I did have other tubes, originally had Dougs Tone kit installed. That woke up CH2 Mark1 mode. I actually liked that more than any of the CH3 modes until now. The lower gain 5751 prevents the high frequency amplification in the first two stages and provides more headroom. Before I made the swap, I did not care much for the gain on CH3 above 9:00 (caused loss of definition and high treble that could not be tamed with the presence or parametric EQ). Now I can crank up the treble control to get the same effect if I wish or tone it down (yep the treble control now works, before it did not make any difference wither the knob was set). CH2 is much better as well (especially the Mark I mode). CH1 has also been improved. I can get a higher output with the gain setting without early clipping.

Per Dougs tone kit but slightly different (one of the pentas when microphonic so I changed it with and EH, removed the other two and replaced them with the stock mesa tubes)
v1 JJ ECC83 (110/110)
v2 Ruby 12ax7ac7 HG (115/120)
v3 Tung Sol 12ax7 (115/115)
V4 EH12AX7A (?/?)
v5 Mesa 12ax7A (?/?)
V6 Mesa 12ax7A (?/?)
V7 Sovtek 12ax7LPS (110/110)

What I have now:
V1 JAN-GE 5751 (?/? in the 70's)
v2 Ruby 12ax7ac7 HG (115/120)
v3 JJ ECC83 (110/110)
V4 Tung sol 12ax7 (115/115)
v5 Tung Sol 12ax7 (unmatched)
V6 Tung Sol 12ax7 (unmatched)
V7 Sovtek 12ax7LPS (110/110)

They are a bit pricey at $39.00 each. I found them at "thetubestore". Dougs tubes did not have what I was looking for.

 

[stokes]

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.

 

[bandit2013]

I have had two other Marks (III and IV) and never had any issues with tone using all the same preamp tubes.
I have rolled the tube in other sockets just to experience the difference. It did not do so well in other locations. V1 had the best results. Now I can finally say that the Mark V provides the best sound that I have experienced through any amp. After getting some hours of burn in on the tube, the tone quality of the amp is now amazing in all Channels. If the 5751 was not the cure for the over the top treble issue, I was prepared to trade in the amp for the Roadster head.

I would definately recommend the 5751 tube as a fix to cut back the brightness of the MKV.

 

[stokes]

V1 gives the most drastic overall improvement,V3,at least in my IIC+ is the drive channel adds some more "smoothness".I have one in V1 of all my other amps,Fender type circuits and Ampeg.

 

[lyman]

I'm using a JAN Phillips 5751 in my maverick head now. I feel like there's plenty of detail in the top end and nice shimmer. I like to set it for an almost-clean sound, where it's just on the edge of breakup. Nice tube! With new stock 12ax7's I usually liked it on the 'bright' setting and felt that 'fat' was somewhat boxy sounding, but now I'm enjoying the fat setting.

 

[mesa metal]

@bandit2013 I noticed you have three tung sols In V4,5,6.
after playing them for a few days how is the amp sounding....im thinking of going with the 5751
to try it out......... I have my tube setup in another post.....

 

[bandit2013]

@bandit2013 I noticed you have three tung sols In V4,5,6.
after playing them for a few days how is the amp sounding....im thinking of going with the 5751
to try it out......... I have my tube setup in another post.....

I originally had the complete Dougs cocktail with Penta 12ax7 in V4, V5, V6. However, they went microphonic on me. I got the Tung Sol's as replacements. Since I did not have them matched, V4 - V6 seemed okay for their use (circuits for these tubes are essentially drivers.) As for tone, I like the preamp tube arrangment that I am currently using. The most important tube locations are v1-v3, and v7 (PI).

As for the sound, It is getting better every day. I think the magic was definately the 5751. There were no ill effects on any of the channels. Just a slight reduction in gain but that can be adjusted by the gain setting for each channel. Before the 5751, I could not adjust the gain or treble above 9:00 and tolerate the ear piercing highs. It helped to cut back some of the treble.

If you can find the JAN-Phillips 5751 it is supposed to have a better sound quality than the JAN-GE 5751. Either way both the military JAN tubes are better than the newer versions as I found in research.

 

[mesa metal]

with the exception of the ruby tube I already have all the others...
im ordering a jan Phillips from tubedepot...tonite....
I never had any problems with the treble or gain adjustments in my V but the lower gain tube
will most likely help with the piercing highs..
are you running the head or combo..and are you playing stuff on the heavier side??
I did contact the tubedepot and they recommended this tube very highly....it will be 35 bucks plus shipping
im using the lps in the PI slot as well ,,,,,,,,,,,,,,not to crazy about Chinese tubes for some reason.....
thanks for that info
what are the gain reading for the tungsols in the v5 and 6
http://tubedepot.com/5751.html

 

[bandit2013]

I play just about anything, depending on mood. I enjoy playing classic rock, hard rock, blues, and of course anything on the heavy side. I love the clean channel on this amp. It is the Mark 5 head played through a Mesa Rectro cab stuffed with EVM12L black labels. There is plenty of gain available without raising the bar on the treble which was a bit over the top and could not be controlled with the 12ax7 in V1. The lower gain provided more definition in all channels. No mud slinging either. I decided to use Tung Sol 12ax7 in V4-v6 since they seem a bit more robust than the Penta's I got from Dougs Tubes. Tung Sol tubes I believe are military grade 7025. The plates are welded together not crimped like most 12ax7. I have not noticed if they add any darkness to the overall tone. I could try a high gain in V6 since that is the last gain stage for CH3. So far I am pleased with the preamp tube arrangement. As for the final tone I have a matched quad of 7581 power tubes (tried to get winged = C= from Doug by ordering 2 matched paris, however he suggested the Ruby relabeled GT tubes for my AMP, I settled on the Tung Sol, a JAN 5U4G and EH12AX7 [for the MKIV]). Those are also Tung Sol tubes. I am pleased with them because they have not yet red plated like the mesa stock tubes.

Now If I compare the MKV to the MKIV, hands down the MKV is a better amp. My opinion was the other way before using the 5751. Single note soloing on CH3 in extreme mode with all the parametrics set to 11:30, the gain and presence set to 1:00 running either 45W or 90W at full power is awsome. Nice definition on soloing and hit a chord it becomes an instant axe grinder. Now for the important part, the instrument. Currently I have 3 Carvin DC400's (two of which are walnut), one DC200 Koa, and one DC100 hard rock maple. They all have thier own sound character. The Clarow Walnut DC400's are may favorite since they produce great sustain, bright highs and growling lows. Pickups used are the metal covered S22's which are low to moderate output which I found work best on a walnut guitar. Heavy metal to the max in tone, but yet awsome with other styles of music. I will have to convince my friend from work to bring over his Strat, I would love to hear it though a Mesa.

As for China tubes, do not undermine them. They can produce high quality components as long as they maintain the same manufacturing procedures and process. I used to think the same when the Sovtek tubes became available in the late 80's.
All of the tubes I had in my MKIV were chinese. I bought that in 2000. I just recently replaced all of the tubes in beginning of November last year. As with any tube, does not matter who makes them, it can be hit or miss since there are many factors that effect performance and longevity. Most of the problems arrise from shipping. Mesa, Dougs Tubes, and other distributors will screen the tubes. Question is how many do they find as defects or out of spec? Even the JAN (military - USA) parts can be defective, I ordered a replacement JAN 5U4G which was supposed to be bulletproof, found one of the diodes was shorted (tested the rectifier after blowing several fuses - fuses on hand were not the correct type, left overs from the MKIII). Sent that back under an RMA to Doug. I hope I get a replacment.

 

[mesa metal]

well my jan Phillips 5751 is on the fedex truck and will be here Monday..and as for the winged c tubes doug had stated he is not going to be carrying the 6L6 any more because they changed the materials being used and were not testing well and too much money,,,,,thats a shame cause I have a set in my 50/50 amp and really like the bottom end they produced...so im going to put them in the V and give them a listen.....for the V6 currently im using a high gain JJ 115/115..and for v3 there is a tungsol 110/110 in there,,,but its all going to change when I get the 5751..i love my tone now but there is something that's just not there...the treble sometimes can be a bit over the top but I was adjusting that with the eq......and I want to use channel 3 extreme mode more often......I like the brutal tone im getting from that........it seems as im getting older the heavier the music im listening too
so how are the 7581 in the V are you getting some good bottom end from them.......im starting to be a fan of tung sols but have not tried the power tubes yet..was thinking to get the Tung-Sol 6L6GC-STR when the stock mesas go blammo...and the price is better than that of the SED-C-6L6
id like to hear that koa carvin is it a neckthru version? im playing Jackson neckthru mahogonys and the sustain is fantastic but it weighs a ton..
thanks for your feedback on your tube arrangement there is a few of us on here with similar playing styles and the music we like and not to mention the tone we want from this amazing amp......for me its quite a change from my previous triaxis/2:90 rig.....the V has the best clean channel ive ever heard!!!
ill let you know how the tubes sound later in the week,,,i have to decide wich tube to put in V3.. :? .

 

[bandit2013]

All of the guitars I have are neck through (except the dc100 which is a set neck and blended without any heal).
The DC200 is too light to be mahogany, the grain pattern and suttle flames in some areas of the woood looks more like Koa (plain jane, not the AAA flamed koa that is prized for its appearance). It is the lightest one of the lot. The DC400A has a maple cap over Alder which is about a pund heavier than the DC200. So far, the DC400 Claro Walnut guitars I own seem to have the more pronounced tone with incredible sustain, deep low end and bright top end. The only difference other than tone woods between the DC400's and the DC200 is the neck thickness. The DC200 has the thinnest neck I ever played. The fretboard is just as wide as the other guitars bit it is super thin. I thought my Charvel model 4 had a thin neck, not as thin as the DC200. I had Carvin run the serial number so I could get more info about the guitar, they had no data to report. I found it used, so it does not matter, it is still an awsome guitar.

The CH3 in Extreme mode is my all time favorite on the V. I mix it up when I play. I may spend half an hour with blues on CH1, crank out a new song I am learing (good times- bad times) in CH2 crunch, then replay it in CH3. Just about any ACDC tune sounds great in CH2. I do like the MarkI in bold.

I would have to say the 7581 sound similar to the 6L6 GC STR420 coke bottles that came with my Mark IV. Tubes are quiet and do not sing like the STR420' did at low volume. They seem well ballanced in tone character. Very close to the 6L6 sound. They seem to fall in between 5881 and 6L6.

 

[mesa metal]

some nice guitars man ,,and also the charvel 4,,that is one of my faves,..I also have a model 5fx and a 550XL fusion that im currently rebuilding,,,,,those necks are great to play for sure..but the SL2MAH is my main axe for now...
I got the 5751 today but wont have time to switch things around till the weekend....going to do a similar setup as yours with the exception of the ruby.in V2,(don't have one yet),,i have a high gain tungsol im going to put in V6 and stay with the LPS in V7...
thanks for the input on the power tubes,i will eventually try those out in the near future,,my tube collection is growing pretty fast..
,,cant wait to crank extreme mode with the new tube setup.......its pretty cool how channel2 sounds like the old ac/dc tone i really enjoy it and sometimes I find myself playing on that channel for awhile...
ill post my 'report' soon as I get the tubes in......right now im thinking to put a mullard in V3 and a high gain jj in V2

 

[bandit2013]

Unfortunately, my charvel did not live another day past December of last year. Long ago I removed the active electronics in favor of Seymore Duncans. Too many mods to say the least. I was going to rebuild it, neck screws were shot, frets wear was excessive. I did remove all of the parts in prep to rebuild, estimated the cost to rebuild was higher than it's value. If it was in mint condition I may have considered it. It was well past it's prime and met with the banjo at the bottom of the dumpster along with the accordian. (What is the definition of perfect pitch? It is the sound a banjo makes hitting an accordian at the bottom of a dumpster. A joke I heard a long time ago. ) See what happens whey you buy too many Carvins, nothing else matters.... The only non-carvin guitar I own is a Yamaha 12 string. Carvins may not be for everyone, if you have a style or brand you prefer, stick with it. I got so used to the 25" scale that I found myself lost or alienated when trying out other guitars of different makes, including PRS, Gibson, Ernie Ball, ESP, etc.. OOPS, I am hijacking my own thread..... Lets keep it to the topic.

Did you get the JAN-GE or JAN-Phillips? I was originally after the JAN-Philips but could not find it. So far I am please with the GE version.
Is your amp a combo or head? When I was rolling the preapm tubes, I had the chassis pulled with the reverb tank and placed it on top of the 412 cab. It may have been upside down but that made rolling an easy task until I was satisfied. If you have a combo, that trick would be a bit more difficult. Sooner or later I will have to get some EL34's. They sounded great in the Mark III couples with 5881 on the outer sockets. In power tube selection, stick with the higher wattage tubes. There are many that fall into the 25W category, Most of the 5881 are 25W so I opted for the 7581 which are 30W. I am happy with what is in the amp for now, until something blows out. So far I have not red plated them like the stock tubes which were probably damaged during shipment and then a 500 mile trip from PA to NC in very cold weather.

 

[stokes]

If you are talking about current production 5881's,they are 30watt tubes,like the 6L6GC.I think that Sovtek is making a "Tung-Sol reissue" that they say is rated like the originals at 23watts,but I have my doubts that they are any different than any of the current production 5881"s.More likely your tubes that redplated did so because they didnt fall into the proper bias range for the amp.Do you have a bias adjust pot installed?Very easy and useful mod if you want to use tubes of an unknown current draw or NOS power tubes.As for the 5751's,I have roughly 20 or 25 NOS 5751's of about every brand in my collection,not counting the dozen or so in various amps I have.I wouldnt be too concerned about getting a particular brand,such as the JAN/Phillips,I have found all the old stock tubes sound fantastic,there are some differences but in my opinion,they are minor.The current production 5751's all sound like cheap,weak chinese AX7's,at least the ones I've tried/heard.

 

[tonedragon]

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.

 

[mesa metal]

that's a bummer the charvel didn't make it....
i got the jan-phillips 5751 from http://tubedepot.com/5751.html i got the balanced option in case i want to try it in V7....they are a great place to get tubes along with doug....
i got the combo amp version due to the fact it is easier to change out the tubes ive only had it since December and im on my 6th tube swap...and i just got a recto 2x12 to go with it and sounds awesome...i do have a 4x12 recto but wanted to keep the V separate from my 2:90/triaxis rig.
as for the power tubes im going to try the tungsol 7581 when the mesa str440s go poof...they seem to get good reviews but either way i want tubes that produce a good bottom end to my sound...i wanted to get sed-c- 6L6 but doug is not going to sell them any more due to the fact they cost too much and they changed the materials being used and were not testing very well,,,,
so this weekend ill be putting the 5751 in V1 and changing things around..ill let ya know how it sounds...going to try the tungsols in4,5,6 also
not sure about V2 and 3 yet....ill post what positions i put in......by the way the 5751 came in at 95/95 so it should sound really good..and if i like it i will get a couple more to have on hand..
:wink:

 

[bandit2013]

If you are talking about current production 5881's,they are 30watt tubes,like the 6L6GC.I think that Sovtek is making a "Tung-Sol reissue" that they say is rated like the originals at 23watts,but I have my doubts that they are any different than any of the current production 5881"s.More likely your tubes that redplated did so because they didnt fall into the proper bias range for the amp.Do you have a bias adjust pot installed?Very easy and useful mod if you want to use tubes of an unknown current draw or NOS power tubes.As for the 5751's,I have roughly 20 or 25 NOS 5751's of about every brand in my collection,not counting the dozen or so in various amps I have.I wouldnt be too concerned about getting a particular brand,such as the JAN/Phillips,I have found all the old stock tubes sound fantastic,there are some differences but in my opinion,they are minor.The current production 5751's all sound like cheap,weak chinese AX7's,at least the ones I've tried/heard.

I bought the V head in November of last year. The tubes that red plated were the original Mesa tubes that came with the amp. My rectro cab is 13 years old and spent most of the time in storage. After burning through 6 sets of tube that I had available, All 4 of the stock tubes are now toast. along with two of the STR420. I decided to rebuild the cab completely. So far the 7581 (first of the non-mesa branded tubes that I have used in the V) had no issues. I would not doubt the tubes were bad or that there was something wrong with the amp. So far everything seems stable, the chassis will get warm not does not seem to heat soak anymore (I can actually touch the chassis without getting burned, I can tolerate 180°F which is the UL limit on ballast resistors for a class 2 thermostat, the chasis would soak to a point where I could not touch it, too hot, even the speaker plug along with front of the chasis was heating up). Bias adjust pot? No the amp is practically new and I do not want to alter it at this time. Besides that, you need a meter to measure the current for the bias setting. I have seen the bias meters, looks like something worth while. Yes, many of the reviews on the new build 5751 did not get good ratings like you said cheap and weak. Most of the comments I have seen were biased towards the Phillips over the General Electric.

 

[bandit2013]

that's a bummer the charvel didn't make it....
i got the jan-phillips 5751 from http://tubedepot.com/5751.html i got the balanced option in case i want to try it in V7....they are a great place to get tubes along with doug....
i got the combo amp version due to the fact it is easier to change out the tubes ive only had it since December and im on my 6th tube swap...and i just got a recto 2x12 to go with it and sounds awesome...i do have a 4x12 recto but wanted to keep the V separate from my 2:90/triaxis rig.
as for the power tubes im going to try the tungsol 7581 when the mesa str440s go poof...they seem to get good reviews but either way i want tubes that produce a good bottom end to my sound...i wanted to get sed-c- 6L6 but doug is not going to sell them any more due to the fact they cost too much and they changed the materials being used and were not testing very well,,,,
so this weekend ill be putting the 5751 in V1 and changing things around..ill let ya know how it sounds...going to try the tungsols in4,5,6 also
not sure about V2 and 3 yet....ill post what positions i put in......by the way the 5751 came in at 95/95 so it should sound really good..and if i like it i will get a couple more to have on hand..
:wink:

I did like the Charvel as it was my main axe for a long time (I liked the neck on it better than my LP, I would almost consider bying that back but probably could not afford it now which is probably over $5k by now if it were to go up for sale, wish I never sold it). The Charvel was replaced by the Carvin DC200. Talk about night and day difference. Two more Carvins later, the Charvel was easy to let go, like I said it was not in good shape after may years of use and too many mods.

I bought my 5751 and the tung sol's through tubedepot as well. I was a bit disappointed with Doug's tubes due to the dud I got for the 5U4G. I have yet to see a replacement. Money lost, lesson learned. I sent it back under an RMA, will see if Doug sends a replacment. I chose the Tung Sol's based on their construction and build quality. I may consider building an inventory of the 5751 as well as other tubes, I have boxes filled with mesa 12ax7's, need to test them and weed out the bad ones. Waiting for the Orange VT1000 to become available. I was considering the Combo V but already had the MKIV combo along with Rectro slant 412 (looked like something was missing so opted for the head).

 

[stokes]

Bandit,if your chassis was getting hot as you say,it is likely the power tubes were biased too hot,very uncommon in a stock Mesa with Mesa tubes.They set up their amps to be biased extremely cold.Never seen a Mesa with stock tubes biased any hotter than 25ma's,and usually colder.I have found most are best at about 35ma's and some a little hotter.While the 7581 is a 30 watt max tube,it was replaced with the 7581A which is a 35 watt tube when the 6L6GC came to be.What brand 7581 are you using?

 

[mesa metal]

I bought my 5751 and the tung sol's through tubedepot as well. I was a bit disappointed with Doug's tubes due to the dud I got for the 5U4G. I have yet to see a replacement. Money lost, lesson learned. I sent it back under an RMA, will see if Doug sends a replacment. I chose the Tung Sol's based on their construction and build quality. I may consider building an inventory of the 5751 as well as other tubes, I have boxes filled with mesa 12ax7's, need to test them and weed out the bad ones. Waiting for the Orange VT1000 to become available. I was considering the Combo V but already had the MKIV combo along with Rectro slant 412 (looked like something was missing so opted for the head).

what were the plate current(ma) readings for the tunsol 7581 you got from tubedepot...they are a great store and im sticking with them for awhile...
I would like to get the VT1000 as well and it not a bad price for what it does.but I was looking at a maxipreamp tester http://maximatcher.com/
but it cost quite a lot more so im not sure if I can justify such a purchase,,but then again im getting a lot of tubes that I do not know if they are really that good or not,,,i like to see what the gain readings are for most tubes...
I most likely will get a set in a couple of weeks...of the tungsols..