What preamp tubes to get for Marshall JMP-1?

[johnjm22]

I have a Marshall JMP-1 guitar preamp and I'm about to replace the tubes. I've been told that I need 12AX7 tubes, but I was wondering if there is any quality differences among the companies that make 12AX7 tubes (electro-harmonix, tesla, groove tubes ect.)

Also I'll be using the JMP-1 for mainly heavy distortion. Should that effect my decsision on what tubes to get? Are certain tubes better for that purpose?


***WARNING DUMB QUESTION***

Okay I've never bought tubes before, so my question is are these 12AX7 tubes something that you can just buy at guitar center? Or do you have to order them?

[karl]

I have a JMP-1 and have replaced the valves a couple of times. I did not notice a big difference. Maybe the Marshall valves sounded a little better than the cheap Eastern European ones. You do not need to replace them very often though.

[LumenStudio]

I got 4 of these for my TSL 602 combo:

http://www.groovetubes.com/NAMM2004_04.cfm

from

http://www.kcanostubes.com

I really dig the tone of these tubes, smooth and just great tone (hard to explain). I also put in a celestion greenback 25 in one of my mesa 1 x 12's and that was a good touch too. I'm able to record at relatively low volumes with this setup and get a great tone.

Cheers,
Lumen

[twilt]

i second the groove tubes notion.
depending on how much use your unit has seen (and how hard you drive it) i would have a TECH look at it at least every 4 years.
twilt.

[NIGHT'SCHILD]

The groove tubes idea isn't bad. They make a Mullard 12ax7 re-issue which is great in Marshall amps. The vintage Marshall amps made in the 60's and 70's used Mullard tubes made in Great Britain. Those tubes are awesome! You can buy tubes at GC but they will rip you off. There is this really cool place in my hometown called Antique Electronic Supply and they carry high-end New Old Stock tubes like the 12ax7 Mullard. Pricey but well worth it for the tone you get. Check out www.tubesandmore.com

[Jack Pettit]

Think of vintage tubes like fine wine.
OK I'm a tube nut, anyway back to the question.
If everything is working in your amp, good power tubes
with the bias set correctly then pre amp tubes can make a
subtle but noticeable difference.

New 12AX7's I like
JJ Tesla
Groove Tube Mullard clone ( doesn't sound like vintage mullard)
Chinese tubes marked TNT (lots of bite)

Vintage
Real Mullards
Brimars ( cleaner )
RCA's

For my tastes
I think the Mullard CV4004 is the best pre amp
tube ever made for guitar amps that use 12AX7's
Fender or Marshall or most others.

Just my 2 cents

[karl]

Do you think the groove tubes mullard reissue pre-amp tubes would make that much difference in a JMP1? I really couldn't tell that much difference between the cheap valves and Marshall branded. It is hard to tell because when I have changed valves there would always be an improvement of some kind because they are new.

[johnjm22]

Well I'm mainly worried about heavy nu-metal deftones type distortion. So what do you guys think the best tubes for that would be?

[LumenStudio]

Originally posted by karl
Do you think the groove tubes mullard reissue pre-amp tubes would make that much difference in a JMP1? I really couldn't tell that much difference between the cheap valves and Marshall branded. It is hard to tell because when I have changed valves there would always be an improvement of some kind because they are new.

Yes they do make a difference. I swapped out stock marshall tubes and there's a difference, it's really hard to describe it though

Cheers,
Lumen

[LumenStudio]

Originally posted by johnjm22
Well I'm mainly worried about heavy nu-metal deftones type distortion. So what do you guys think the best tubes for that would be?

Tubes will help but this will help a lot more (not the ltd-version): http://espguitars.com/sig_stephen.htm

I've had one for the last (?) five years and I put all my gibsons to rest. I'm a huge deftones fan as well.

Cheers,
Lumen

[NIGHT'SCHILD]

For the heavier distorted sound with a lot of gain but low noise I would use the 12ax7 Groove Tubes Mullard re-issue. As somebody said before it doesn't sound like the vintage Mullard but has the characteristics you are looking for.

[jbuntz]

Most marshall stuff works better with ECC83's (british 12ax7's). They are fuzzier and darker.

[NCNDude]

Here you go dude. All the tubes you could ask for. I've ordered there a few times. I got good service.

http://www.thetubestore.com/

In case you don't spot it they have a nice review section of various tubes.

http://www.thetubestore.com/12ax7review.html

[karl]

I'll definitely give the Mullards a try. However, when you look at the Tubestore they say that Goove tubes are just rebranding at a higher price. Which 12ax7 is the mullard you talk about?

[karl]

Also, anyone know which tube Marshall brand? It seems there are only about 3 companies who make them. Sovtek, Svetlana and Tesla.

[Jay Kahrs]

There are about six factories that make tubes, mostly in Russia and China. Groove Tubes, EH, Ruby, Sovtek etc. all get their tubes from the same places and grade them differently by testing and sorting them. In something like a JMP-1 I highly doubt that you'll hear much a difference between different tubes like you would with a point to point amp like a vintage Plexi or a Matchless. Keep in mind too that a lot of newer amps are designed around the tubes you can buy today and putting in NOS Mullards would be a total waste of money and good tubes.

[karl]

Originally posted by LumenStudio
Yes they do make a difference. I swapped out stock marshall tubes and there's a difference, it's really hard to describe it though

Cheers,
Lumen

Lumen. Are you talking about a JMP1 here?

[LumenStudio]

Originally posted by karl
Lumen. Are you talking about a JMP1 here?

Karl, good call. I have not heard the groove tubes in the JMP1, which is what the original poster asked. I hope I did not mislead anyone. I have only tried them in my Marshall TSL 602 combo. I liked them better than the stock tubes, better than mesas that I tried, and better than Electro Harmonics. This is so subjective though (possibly more so than most topics discussed here). It seems to be a smoother distortion where notes articulate slightly better.

Harmony-Central has a guitar players forum, maybe you might want to check over there for some opinions. I don't think the groove tubes will make the JMP-1 sound worse than with stock tubes, but yeah never know.

Remember this is only a small percentage of the chain. The guitar, amp, and cab are way more important. As far as the recording chain itself is concerned I use the 121 -> TG-2 -> Vintech X73i EQ and I think it sounds great. It has that major label vibe.

Cheers,
Lumen.

[karl]

Thanks. This is exactly what I was thinking. I'm not sure that pre-amp tubes have as much affect as power-amp valves. Also I think that they have even less to show in rack units than amp heads or combos for some reason. I really did not see a huge difference from the Marshall valves to the unknown brand which were pretty cheap. In fact the cheap ones sounded better because they were replacing old tubes. The only way you could really tell would be to get several sets of new tubes to compare. As I understand it even two sets of the same make can sound different. The biggest improvement in my guitar sound recently was some Apogee gear for recording!

[johnjm22]

Well I went ahead and bought the Groove Tubes Mallard reissue. I'm expecting them to come in sometime this week. I let you guys know if I notice any difference.

[karl]

Definitely let us know what happens. I'll be interested. Thanks!

[karl]

Any news John?

[johnjm22]

Sorry for the late reply.

I can honestly say that I didn't notice any difference with the new tubes.

[Onan]

Doh! The tubes are fully 1/2 the sound of a guitar amp! (I'm a little obsessive about this subject.) Every brand and model of tube has a different sound. For the preamp stage, my favorites are Telefunken and black-plate RCA. For el84 and el34 power tubes, Mullard is king.

This is just as delicate and subtle as choosing a mic/pre combination for the lead vocal track. Make no mistake, fiddling for a whole day with a wide selection of vintage tubes will open your ears to a world you never imagined existed.

If you have a budget, buy Telefunken 12at7, 12au7, and 12ax7 (aka ECC81, ECC82, and ECC83, the European codes). Also buy the same models of black-plate RCA's. Ditto Mullard (although Mullards are the most "neutral" of the bunch, and I don't use many of them). The "at" and "au" are lower output, so if you know you need heavy overdrive, you can skip those. But I use them, crank the gain up higher, and forego the option of heavy overdrive. NOS teles are maybe $40 each; good used maybe $30 each. RCA is a little cheaper. The RCA's MUST be black-plate. Some people think Tele ribbed are better than Tele smooth, but I like them both.

I'm not familiar with your amp, but a typical amp might have 2 to 5 preamp tubes. One is first gain stage, a second is volume stage to the power section. One may drive the eq. Another pair may drive the in and out of the reverb loop. I find that it doesn't matter too much what tubes (even cheap Chines tubes) drive the reverb loop, since it's sorta just noise (not the direct tone of the guitar) going through the reverb anyway. But for the gain and volume stages, I'll spend hours swapping different tubes in different orders and different outputs (ax, at, au). If you want to get a taste without diving headlong into the pool, just start with 12ax7 (ECC 83). I have experimented with GE, Sovtek, Svetlana, no-name Chinese, grey RCA, Sylvania, Mesa, Groove Tubes, etc. Some improvement can be found from GE and Sylvania, but it is well worth the extra $ for Tele and black RCA.

The ONLY power tubes I use are Mullards (except in my 6L6 amps, for which no Mullards appear to be available, so I use Ruby and Mesa). A NOS pair of Mullard power tubes can cost $200 or more, but NOS isn't necessary. I buy all my tubes on ebay from guys who have long histories of selling tubes, and I've never been burned. Learn to identify good quality used tubes, and you can save a bunch. Also, Mullard made tubes for a lot of other companies, who rebranded them. Reputable dealers will tell you "These are Mullard-made Valvo-branded xf4 EL34, 95% output, no gas, no shorts." That sort of thing. Good used Mullard power tubes are about $100/pr. or more. They should be "matched" pretty closely; a good dealer will sell you reasonably matched pairs. Matching makes no difference in the preamp (unless you're trying to do exactly-matched stereo), because the preamp tubes are linear to each other, not summing the same signal simultaneously.

Vintage rectifier tubes can be very expensive, but I have not detected an audible difference between cheap and expensive rectifiers.

Note that I don't think these tubes sound better because they ARE "better" in any objective sense. My guess is that they are less perfect from a technical standpoint, but that their imperfections are the reason for their quality IN GUITAR AMPS. I don't put vintage tubes in my mic pres or anything (though I've never tried it, so who knows...)

Beware, tube addiction is a serious financial health hazard. But if you're a serious guitar player, the tubes you choose are just as important as the amp itself.

Have fun!
Lee

[Blast9]

Well the JMP1 is a MIDI preamp, not an amp (Analog signal path/digital controllers)

Its quite possible the tubes are not responsible for much of the tone generated... Marshall did use diodes/LEDs for the overdrive in some of their products...

So maybe its not strictly a "tube pre"... I remember the clean sounds on my JMP1 were very hard and Solid State feeling/sounding... Not a patch ( :-) ) on the Mesa Boogie Triaxis, which IS all tube

Apparently you can remove the tube from the Valvestate, and you'll still get your overdrive channel! Indeed, I remember opening mine up once, and when I hit a power chord these 2 LEDS would light up!

[Onan]

Well don't I look silly!

[Blast9]

Actually there IS a JMP or JPM amp (can't remember)... its one of the early master vol amps from the 70s I think... Dave Sardy uses modded ones!

So there's your get-out clause!

[LumenStudio]

Originally posted by johnjm22
Sorry for the late reply.

I can honestly say that I didn't notice any difference with the new tubes.

I just thought about this thread as I am testing out a bunch of amps that I'm selling (and not really like selling any of them, but a house down payment is friggen expensive).

Anyway, sorry to hear about it not making much difference in your sound! It did make a difference in mine for sure. I guess that tells us a little about how the JMP-1 works. Anyway, deftones have an incredible guitar sound with that preamp being part of it, so definitely check out the signature ESP. I have one and it is awesome. Scrounge up what you can and get one!

Cheers,
Lumen