I just picked up a used Nomad 100 1X12. When I got it, it had a mix of Groove Tubes and Marshall power tubes that appeared to be from the Nixon administration era. I re-tubed with Mesa 6L6s (yellow) and it sounds great. However, I would like to experiment a little with the tone. I have a set of Electro Harmonics 6CA7s in my Hughes and Kettner and I love the tone I get from them. I'm not a tube guy but I read that these tubes are described as EL34s on steroids, which describes my experience with them in my H & K. Are the EH 6CA7s compatible with the Nomad in the EL34 bias mode and if so, how do I know which ones to select that are compatible with the MB fixed bias? I know for example that with Groove Tubes' proprietary bias rating system, the 4,5,or 6 GT ratings are compatible with MB fixed bias. But how do I know what "non-Mesa" or "non-Groove Tubes" tubes will be compatible with the MB fixed bias?
Tube replacement with other than Mesa or Groove Tubes.
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shimmilou
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Hi davolk,
If you ask many vendors, they can supply tubes that will be rated for MB amps, just specify the amp and ask them. :idea:
Otherwise, you can use a bias probe to check the current for the tubes that you have and see if they are compatible.
If you ask many vendors, they can supply tubes that will be rated for MB amps, just specify the amp and ask them. :idea:
Otherwise, you can use a bias probe to check the current for the tubes that you have and see if they are compatible.
Thanks. This is the first MB I've owned. What's your experience with MB tubes versus other brands? The MB 6L6s I put in sound fine, but I don't get single note definition and clarity that I get out of my H & K. Is that a tube thing or an amp thing?
shimmilou
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It depends on which Mesa tubes that you have. Mesa uses, and has used many types, including various Russian brands, some Chinese, and even JJ. In my TA-15, the output tubes are Russian (EH I think) and the preamp and PI are JJ, and I actually prefer them over the other types that I've tried. I tried Mullard reissue and GT Sovteks in the output, and I tried Tung Sol reissue and Chinese GTs in the preamp and PI. I thought that the initial tones from the amp were terrific, and none of the tubes that I tried improved the sound. I liked it so much, that I bought two complete replacement sets of the same Mesa tubes for my amp. But, it's all according to taste. The sounds that I like might not be the same for someone else, and the other tubes might be perfect for the tones someone else wants. Probably the best way to know is to try for yourself, and rolling tubes can be expensive, depending on how many types that you want to try.
davolk said:
Did you get the manual with your amp? if not check Mesa website, they have downloads for almost all models current and out of production. The manual should have a tube assignment chart or image indicating what preamp tube does what... Also there should be recommendations for power tubes.
Power tubes of various brands do have a tone as well as different gain characteristics (harmonic content). Some of the distortion you get is from the power tubes and some is created by the cascading preamp tubes.
Good power tubes that I have tried in both my Mark V and Mark IV.
6L6 type
TAD6L6GC-STR ( a bit dark and sinister when overdriven, really nice on the clean side)
SED 6L6GC: this tube has performed the best and served me very well. Reflektor/Sovtek brands: Svetlana 6L6GC, not bad, almost close to SED tube but not quite. TungSol 7581, cross between the TAD and SED in tone and harmonic content. A bit brighter than the Svetlana.
EL-34 type:
EH EL34. Sounded thin at first but really blossomed into the TAD6L6/SED6L6 territory. (note TAD are Chinese made for Tube Amp Doctor, SED is made in St Petersburg Russia. The Best tone I have heard yet was from a quad of JJ6CA7 but they were short lived (2wks) then poof, so I will not recommend them.
With power tubes, indicate manufacture and model of amp. Also you should also indicate it is for Combo if your amp is a combo. Note about EH EL34 tubes, they rattle. Some of the high end audiophile shops stopped carrying them for that issue.
As for the preamp tubes, use match triode tubes for the PI position (usually last tube in chain, v5). I have liked the Sovtek LPS for the PI, same as Mullard reissue. Both are long plate designs. A bit lower gain than the medium or short plate tubes. I have also tried Tung Sol with good results. (based on the tube task chard for the nomad, you only have one driver circuit, so sticking with medium to short plate preamp tubes would be best performance. Tung Sol works great in V1, but for the remaining stages, higher gain tubes will have a dramatic effect. High Gain JJ work best in the latter gain stages. If you use a high gain preamp tube in V1, your clean tone for normal mode in ch1 may have more breakup than you desire. Just get a few of the high gain tubes available the try them out. It is mostly trial and error. preamp tubes will fine tune your tone as well as effect power tube tone.
Good luck with what you decide to do.
DangerMoney
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shimmilou said:
I've bought several MB 6L6s in the past few years and while the tone was fine, one in several matched pairs went microphonic within six months. Consequently I no longer buy MB tubes. I now use Tung Sol exclusively for both power and pre-amp sections. The Tung Sol power tubes have been in for over a year and none have gone microphonic.
The vendor I but them from always asks what amp the tubes are going in for all power tubes. I tell them what MB amp I'm putting them in, they select the appropriate tubes and send me matched quads or pairs. Each individual tube box has the Ip and gm values written on it for the tube inside.
I noticed one of my amps was losing high-end response. I pulled all the Mesa 12AX7s out of it and replaced them with brand new Tung Sols. The high-end immediately came back.
YMMV.
shimmilou
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Too bad about the microphonic tubes, that sucks, but glad that you found some that work for you.
It's just what I mentioned in my previous post, different tastes, different suppliers, different brands and different amps. The possibilities are near endless. I typically prefer GTs, and just about every tube made in the Russian Reflektor factory, like Tung Sol and EH, and certain amps sound best with certain tubes (according to taste). I have quit using all pedals/effects and prefer just guitar and amp. Two channels, one clean, one distortion, the right combination of tubes and I'm good. 8)
It's just what I mentioned in my previous post, different tastes, different suppliers, different brands and different amps. The possibilities are near endless. I typically prefer GTs, and just about every tube made in the Russian Reflektor factory, like Tung Sol and EH, and certain amps sound best with certain tubes (according to taste). I have quit using all pedals/effects and prefer just guitar and amp. Two channels, one clean, one distortion, the right combination of tubes and I'm good. 8)
topcat0399
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shimmilou said:
Ahh tubes - a world all its own. Solid State guys are so ignorant!
Good for you on ditching the pedals; I did a dozen years ago - I'm a better player for it.
Thanks for all of the advice. I read some articles published by Myles at guitaramplifierbluprinting.com and was able to get some personal feedback from him too. Myles suggested I also reach out to Mike at KCA and based on a lot of answers by people who know way too much about tubes, I will start with a couple of Rubys and Electro Harmonix, with a balanced Sovtek LPS in the PI slot (which seems to be the rare consensus from multiple sources as the best PI tube). I will ad some Tung-sols in the mix and just start exploring. I'll also try some EH 6CA7s in the power section since I have them in my Hughes and Kettner and they sound great. I'll report back on my progress...
Length of plate has zero to do with gain. For example, JJ tubes are all short plate, but some are tested and chosen for higher gain.
Plate length will, however, have an effect on microphonics caused by mechanical vibration, such as use in a combo, where the speaker shakes everything up. Almost every modern production 12AX7 is a short plate for this reason.
Balanced phase inverters are a hold-over from the tube hi-fi amp era, and are meaningless in guitar amps with do not come close to hi-fi amp specs.
If you hear a difference, that sound is your wallet whispering in your ear.
Plate length will, however, have an effect on microphonics caused by mechanical vibration, such as use in a combo, where the speaker shakes everything up. Almost every modern production 12AX7 is a short plate for this reason.
Balanced phase inverters are a hold-over from the tube hi-fi amp era, and are meaningless in guitar amps with do not come close to hi-fi amp specs.
If you hear a difference, that sound is your wallet whispering in your ear.
davolk said:
It could be either or a bit of both.
Try running the Mesa through the speaker in the H&K.
Using a speaker that works for your preferred tones is paramount. It can make far more difference than swapping output tubes IME.
The first preamp tube is where the rubber meets the road for tone. V1 is usually located nearest the output jack. Try swapping the V1 tube from the H&K into the Mesa and see what difference that makes (if any).
Speaker change and V1 preamp tube are your best bang for the buck when you are tweaking the tone of your amp, get those the way you want and everything else is incremental by comparison.
DangerMoney
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SixVeeSix said:
...and to add to the story:
I've got 3 different MB amps and 3 different cabinets. The big difference comes from the amps. They all sound very different.
The cabs (different speakers in each) make a small difference.
DangerMoney said:
It would be fun to hang out and rip a few licks through your rigs. I agree that the amps make a big difference in sound. My Blue Angel sounded very different than my Subway Rocket or my Mark IIIC.
You would have fun hanging out at my place and listening to the difference when I swapped the stock Black Shadow V90 for a JBL G125-8 in my DC-5. The bass was round and clear, the mids smoother and the highs had more sparkle, it was a profound improvement.
The OP is using a single 12" combo, the speaker is critical. More important is the pick (or fingers), the guitar, the pickup selection but once those are hashed out you start tweaking. We have Jazz players on here and Ultra High Gain players as well. I am somewhere in the middle, I need a good clean but love a sweet, singing Medium High Gain sound for lead work. Going brutal is fun at home but would not work with the band I am in (Roots Rock Originals).
My experience is the cleaner the tone you are seeking the more difference things like swapping speakers and V1 tubes make. If you are shredding the Ultra Gain then differences become much more subtle.
Curious as to your style(s) of playing and the different amps/speakers in you run? I told you what I have.
DangerMoney
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SixVeeSix said:Curious as to your style(s) of playing and the different amps/speakers in you run? I told you what I have.
Six,
Here's the run-down...
Style: Classic Rock
I want amps that can go from super clean to classic rock distortion and anything in-between with the single press of a footswitch:
Amps:
Mark V
Road King, version II
Triaxis through a Strategy 500
Cabs:
4x12 w/ 4 Celestion V30
4x12 w/ 2 Celestion/Black Shadow MC-90 & 2 Eminence/Black Shadow MS-12
4x12 w/ 4 EVM-12L
DangerMoney said:SixVeeSix said:Curious as to your style(s) of playing and the different amps/speakers in you run? I told you what I have.
Six,
Here's the run-down...
Style: Classic Rock
I want amps that can go from super clean to classic rock distortion and anything in-between with the single press of a footswitch:
Amps:
Mark V
Road King, version II
Triaxis through a Strategy 500
Cabs:
4x12 w/ 4 Celestion V30
4x12 w/ 2 Celestion/Black Shadow MC-90 & 2 Eminence/Black Shadow MS-12
4x12 w/ 4 EVM-12L
Nice rigs!! I could see there not being much difference with 4-12 cabs, especially the two that are loaded with Celestions. Each individual speaker is not being asked to yield as much performance potential and you have plenty of bottom end when you can move that much air.
By the time you get up to the level that the Celestions have smoked and died it will be so loud that it is hard to tell a difference anyway. The EVMs will handle massive wattage and put out some serious bottom end long after most speakers have fried but that is "go deaf in 30 seconds" volume in most of the venues I would be playing.
If you tried just one of each speaker in an open back combo you would hear more difference between them, especially if you turned it up a bit.
So, horses for courses.
I was cured of owning 4-12 cabs after I put one under my Mark III for a while. Vox cab with 2 EVM and 2 JBL D-120s in it. I did not like moving it and I could not get my output tubes cooking at any sensible level, even in Class A mode. So I built a Theile cab for one EVM and that was still crazy loud but at least I could put it in my car easily. More power to those who have the muscle!
davolk said:
After various combinations, here is what I'm going with in the Nomad:
V1 Electro Harmonix
V2 Ruby
V3 Tung Sol
V4 Ruby
V5 Sovtek LPS
Channel 1 is crystal clear with a slight edginess. Channel 2 has a crispy crunch with tight low end and very good note definition. Channel 3 is thick with a great low end and great note definition. I appreciate the suggestions.
If you have an EL34 bias switch on the Nomad, KT77 (Gold Lion) are really sweet tubes. I had them in the Mark V for a while and I never wanted to take them out, but since my SED EL34 were too noisy to enjoy in the RA100 when using the clean channel so I transplanted the KT77 into that amp. They are a night and day difference in the Mark V, in the RA100 the difference between EL34 and KT77 is not as dramatic. I would have gone the JJ route but since the 6CA7 tubes blue up within 2 weeks of use, I just did not want to go though all of that again. Gold lion KT77 are expensive but found a good source on EBAY that were matched for my use. Right now I am using the SED 6L6GC in the Mark V. I change power tubes often just for difference in tone. Most of the time I can settle on a tube and it stays in the amp until it dies.
bandit2013 said:
Interesting about the 6ca7s blowing up. I've had a set of those in my H&k for years and they've been great. The peeps at MB said they haven't tested them so they couldn't advise about them. I do have a bias switch for el34s so I'll give the Gold Lions a try too. Thanks for the tip.
I have a 2x12 Maverick and a 2x10 Blue Angel. Over the years, I have tried other brands of tubes and have been consistently disappointed. JJs have been particularly disappointing because they seem to get a lot of hype, and they just don't cut it in these two amps. At one point I thought I read that Mesa was using JJs, but I compared my last set side by side and they were definitely different. I have read different reviews about the Maverick having an ice pick tone, and I'm convinced they're referring to units that have been retubed with non-Mesa tubes.
I'm sticking with the Mesa-branded tubes from now on; they've never let me down. Try other tubes is an interesting experiment, but I've found it to be very expensive.
I'm sticking with the Mesa-branded tubes from now on; they've never let me down. Try other tubes is an interesting experiment, but I've found it to be very expensive.
green_henry said:
The MB preamp tubes I replaced were JJs and the source of my muddy tone. After replacing them with the combination I mentioned above, the tone has greatly improved. In the power sectiion, I put MB "yellow" 6L6s. One tech told me that even though they are Mesa tubes, the yellows are too cold for the Nomad and will sound grainy. The problem I've had is if you ask 5 people you'll get 5 different opinions. Some have told me the EH 6CA7s will be fine as an EL34 substitute and others have said only use MB labeled tubes. So I've taken consistent input from this board and other sources and used it as a starting point for experimenting, which I agree gets expensive.
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