Tube review thread

Soulcrusher_X

New member
Well, there's an amp review thread, and there seems to be a lot of tube related threads going on, so maybe a tube review thread would be useful. Any tube fits here, so let's go! And remember, this is still based off of experience, so let's keep this fight clean!

Just a few 12AX7s that I have tried:

EHX 12AX7: bright and fairly articulate. Might be a little thin in some amps, but has really nice upper-mid grind. Low noise good gain and good harmonics.

TungSol RI 12AX7: similar to the EHX, but fatter. Nice solid low end, detailed top end. Warm mids. Seems to emphasize highs and lows. Good gain and harmonics. Lots of headroom. Only tube that stayed clean in my 3 pre Splawn. I use this tube in V1 of most of my amps.

Chinese 12AX7: Very average in terms of TMB. Doesn't seem to accentuate any one tonal area. Good gain, articulation and harmonics. Nice crunch. One of my personal favorites. I usually use one or two after a TungSol in my amps. I like the Penta branded Chinese tubes. Maybe a touch warmer and more articulate than the unmarked or Ruby Chinese tubes.

JJ ECC83s: Very warm, but a rounded top end. Tight bottom end. Works great in amps that are very bright and have lots of bottom end. They worked great in my PV XXX for example. Doesn't seem to have the harmonic detail of a lot of other AX7s, but they compress easily and have good articulation. The graded HIGH GAIN JJs from a few distributors seem to have more top end crunch and sparkle.

JJ ECC803s: 10% less gain than the JJ ECC83s, but a fuller tone, more top end detail and harmonics. A little 'squishier' than the '83s. Great for vintagey tones. I like these in the PI spot. They seem to make the power section more articulate and open.

Sovtek 12AX7LPS: Warm and average in terms of TMB but a bit rounder on top than say the chinese AX7. Good solid low end and big mids. Great for PI spot. Nice articulation.

Mullard RI 12AX7: Very big and warm tube. HUGE mids and low mids. Slightly looser bottom end than the LPS. Slightly squishy feel but lots of power and midrange grind. Another good one for brighter amps and another good PI tube.

Power tubes:

EL34s

EHX EL34: Pretty good for such an inexpensive EL34. Good articulation, cutting upper mids. Nice crunch and harmonics. Decent highs and lows, a bit lacking in the low-mids. Overall, a fairly musical-sounding, budget-consious EL34.

Ruby/Shuguang/Sino EL34B: I like this tube. BIG and full. Nice harmonic 'swirl' and crunch. Fat mids, solid lows, thick highs. This is one of my favorite EL34s.

JJ KT77: Big and solid like the Ruby, but a little stiffer. Not quite the harmonics and mids as the Ruby, but it has a bigger low end and more top end 'sizzle'. Not as crunchy as other EL34s, it has more of a 'thump'. It's bit like a cross between an EL34 and 6L6 in that way.

SED EL34: CRUNCH coes to mind. These have a lot of harmonics, really fat mids and fat, solid lows. Not a whole lot of high end as compared to the other EL34s, but they seem to have more low end than most EL34s.

6L6s

Ruby 6L6: BIG, open tone. 3D kind of grind. Lots of power and harmonics. SOLID and fat low end, a little loose in some amps. Pretty good mids and highs. Pretty cutting and articulate for a 6L6, can be a bit stiff in some amps.

JJ 6L6: Probably the deepest, but tightest low end from any 6L6 Ive tried. Warm mids, but a little bit subdued. Nice harmonics and top end 'chime' or sizzle. Maybe 'glassy' is the word, but not brittle sounding.

SED 6L6: WARM. Seems to like higher idle current for increased harmonics. Nice, fat mids. Tight, warm bottom end. Warm, defined high end. Overall, a very warm, but big sound. Not too stiff, nice bit of vintage 'sag'.

EHX 6L6: Big low end and low mids, decent mids and a warm, but rolled off high end. Some might call them 'dark'. They are pretty rugged and powerful, but IMO, there are better choices out there.

6550s

TungSol reissue 6550: Bright and articulate. Decently crunchy. Tight low end, big mids and a bright, glassy high end. Like a lot of 6550s, they can come off as stiff.
 
Re: Tube review thread

I agree with the vast majority of what Soulcrusher_X said above, but I'll give my two cents because I need attention and because I think this thread deserves to stay on the front page for a little longer. I'll also limit my responses to preamp tubes since rolling power tubes is much more expensive, and because I've done very little of it.

Tung-Sol RI 12AX7: Big and beautiful. I think this is the crown jewel of the New Sensor factory. The mids don't play a starring role in this tube's EQ curve, but the bass and treble presence lend to maintaining the clarity of the input tone through as much gain as you'd like to send its way. If clarity is the criterion you're after, go for this tube. I like it in V1, and a lot of players agree that this tube is among the best of the new production available.

ElectroHarmonix 12AX7: This is clearly a close cousin to the Tung-Sol. The top end is not quite as defined or clear, and it's a bit thinner because there is more of an upper-mid emphasis. It does add some sizzle, though, so if you're after that, it may be a better choice than the TungSol. If the amp it's in doesn't provide enough gain, the upper-mids of this tube may give the appearance of a higher-gain crunch. I get a higher-gain feel from the Tung-Sol, however, in the way it drives tubes further down the line.

Sovtek 12AX7LPS: A fairly unremarkable tube in the tone-generating stages. However, in driver stages, it works wonders due to its flat EQ. I don't hear anything particularly outstanding about its EQ response, but it perfectly maintains whatever precedes it in the amp. I think this characteristic is why many players use it as a PI tube. In V1 or V2, though, I just don't hear anything to get excited about.

Mullard 12AX7 RI: The black sheep of the Russian factory's lineup. When it comes to this tube, smooth is the operative term. Absolutely huge in terms of drive and mids, it will definitely kill off some top end. The most remarkable thing about it, though, is the way it changes the response of the amp. I've used it in a few amps, and every time, I feel myself playing slightly differently. I don't pick the strings quite as hard, and I don't worry as much about string noise because the drive and high-end response do that work for me. That being said, I find the Tung-Sol clearer and brighter, so I like it better. I do think it's something everyone should try just to give a better feel for what the other tubes do.

JJ ECC83s: Let me get this out of the way. This is the worst of the new production tubes. If the tone doesn't kill your willingness to play, the dull nature of the tube will make your audience think it has. I try this tube every once in a while because people say they like them. Then I promptly open up my amp and throw the tube against the wall as hard as I can. The fact that it's survived this trip multiple times speaks for its durability and against my prospects in the majors. Part of this story was made up.

JJ ECC803s: The saving grace of the Slovakian factory. This is the long-plate version of the 12AX7 coming out of this factory, and it's head and shoulders above the short-plate version. If the short-plate is Khloe Kardashian, this one is Kim. That's a nice way of saying it's still not bright. I put one in my PI recently, and it brought out a bit of clean sparkle that was missing before. I'm a fan of low-gain PI tubes because they don't compress the power section as much, but the sparkle and presence this tube gave my cleans means it may stay there for the foreseeable future. I don't find the added compression on overdriven tones as limiting in dynamics as I got with the Mullard, and I found the top end more musical than with the Sovtek LPS.

Chinese Ninth Gen: My experience with this tube has been the Ruby 12AX7AC5 HG+. It's a giant-sounding tube. It drives the mids authoritatively, and the top end reminds me of the long-plate JJ. When I put it in, I was surprised at how much a preamp tube could bring out the response of the bass and lower mids. I think that this does a better job of taming highs without killing clarity than any JJ is capable of doing. I think this is the best tube of the current crop to give the Tung-Sol a run for its money. The treble response of the Tung-Sol is just enough to outdo it because of how clear it makes the tone.

I like the combination of Tung-Sol in V1 and Chinese in V2. It tames the highs just slightly and provides plenty of gain for a two-tube configuration. At the moment, I have the long-plate JJ in my PI, but I may drop this back to a 12AU7 depending on how my inability to leave things alone acts. JJ also seems to be able to manufacture a good 12AU7, because switching between that and a NOS Amperex is basically indistinguishable.

Anyways, I realized after writing this that I spent a lot of time on a subject I have spent a lot of time and money chasing. I don't think I covered it as well as you did, Jay, but I gave it a shot. I guess it should also be noted that most of my experimentation has been done from late 2010 to early 2012, so things may change as different batches of tubes are generated. Hopefully readers can save some money and time avoiding the mistakes I've made and keep JJ ECC83s's out of their amps.

Great thread idea, by the way. I would sticky the OP only if I could. I'm not nearly narcissistic enough to think my opinions carry the same weight.
 
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Re: Tube review thread

I don't notice enough difference between preamp tube brands or power amp tube brands. In a band mix, I can't notice any difference. However, JJ 83s have been good to me, quiet, and reliable, plus I like the feel....so all my amps get JJ preamp tubes. I use my amp's EQ if I want to adjust tone. Luckily all my amps are very well designed and have very responsive EQs.
 
Re: Tube review thread

I absolutely love the nos RFT ecc83's for heavy metal tone. Very dark with early breakup. I put them in my Peavey jsx in v1, mesa str 12ax7(sovtek) v2, Rft ecc83 v3, and Sovtek lps 12ax7 in the PI. I changed the power tubes from el34's to 6l6's (shuguang's) and biased them a little hot. Raytheon black plate 12ax7's are another favorite of mine, early breakup with great dynamics. Great in v3, because to my ears this slot controls the eq of this amp. I tube rolled a ton of nos ge's, rca's,mullards,telefunken's,amperex hollands,sylvania,tung sol's,etc. Ei is also another great pi tube, very open like the sovtek lps. But they are prone to microphonics. I just bought a Krank rev+1 off of ebay that needs a retube. I will write up on how these tubes effect the proformance. My wife gets sick and tired of me trying to explain it to her, so I'm glad I have people to share with. I've been a lurker here for awhile so, I guess its my turn to give alittle back.
 
Re: Tube review thread

^ the V3 spot in the JSX is actually for tone recovery and the loop driver, so it's no wonder that you noticed a real difference in tone there. Makes me wish I had paid more attention to that. Oops.

My wife actually likes to hear about these things until I get too far off of the basics. Then I get the "you know I won't remember this" after a few minutes. Yep. I love you too honey.

Soon, this thread will be like an AA meeting for tube rollers.
 
Re: Tube review thread

I don't notice enough difference between preamp tube brands or power amp tube brands. In a band mix, I can't notice any difference. However, JJ 83s have been good to me, quiet, and reliable, plus I like the feel....so all my amps get JJ preamp tubes. I use my amp's EQ if I want to adjust tone. Luckily all my amps are very well designed and have very responsive EQs.

I might just be really F-ed up or picky as hell because I wont play certain guitar cables because of the way it changes the tone and feel of my amps. Sure, I know you can change EQ and whatnot, but I think they way a lot of tubes interact with the entire amp architecture is what makes the difference.


Even though Im not such a big fan of the tone of those JJ ECC83s preamps, I WILL say that they are very reliable and rugged. I have never had an issue when I was using them gigging a few nights a week.
 
Re: Tube review thread

One thing to remember...

Some amps respond to different brand tubes and some don't; if you have an experience with a particular tube in a particular amp, a different amp (or a different guitar or different player) may not have similar results.

I guess what I'm trying to say is that any review needs to include some background information as well to be relevant to others.
 
Re: Tube review thread

Mullard RI 12AX7: Very big and warm tube. HUGE mids and low mids. Slightly looser bottom end than the LPS. Slightly squishy feel but lots of power and midrange grind. Another good one for brighter amps and another good PI tube.

Spot-on Mullard review. IS yours actually a 12AX7 or an ECC83 though? I realize they're equal, just ECC83 is what the European version usually is called. Anyhow, I use one in the V4 spot of my Mesa Triaxis. As you said, big and warm with HUGE mids & low mids. GREAT distortion without sounding harsh.

Telefunken ECC83: Very clear and defined, smooth and balanced... I use <> imprinted, Fisher branded, German made Telefunken ECC83s for the V1 and V2 inputs of my Triaxis. Compared to the stock Russian Mesa branded input tubes, the Telefunkens are just so much clearer! These lack a sharp upper mid spike that the Russian tubes have and really smooth out the overall sound. The tubes are very balanced with no specific boosted or cut frequencies. They are just tight enough, but still have a tiny bit of give.
 
Re: Tube review thread

One thing to remember...

Some amps respond to different brand tubes and some don't; if you have an experience with a particular tube in a particular amp, a different amp (or a different guitar or different player) may not have similar results.

I guess what I'm trying to say is that any review needs to include some background information as well to be relevant to others.

I definitely see what you are saying. One tube, the JJ 83s, though I may not be a fan of it in most regards, I stated that it works really well in the old PV XXX I had. That was a very bright amp, and it helped tame a lot of the brightness in that particular amp. Otherwise, in my Mesas, Splawns, Laney, JSX, it wasn't all that stellar.

Otherwise, for the most part, this is just a collection of experiences that were 99% the way these little guys souded in all the amps I have owned. Or at least it's a basic view on how they sounded to me.

You're right though. Everyone's MMV.
 
Re: Tube review thread

Spot-on Mullard review. IS yours actually a 12AX7 or an ECC83 though? I realize they're equal, just ECC83 is what the European version usually is called. Anyhow, I use one in the V4 spot of my Mesa Triaxis. As you said, big and warm with HUGE mids & low mids. GREAT distortion without sounding harsh.

Telefunken ECC83: Very clear and defined, smooth and balanced... I use <> imprinted, Fisher branded, German made Telefunken ECC83s for the V1 and V2 inputs of my Triaxis. Compared to the stock Russian Mesa branded input tubes, the Telefunkens are just so much clearer! These lack a sharp upper mid spike that the Russian tubes have and really smooth out the overall sound. The tubes are very balanced with no specific boosted or cut frequencies. They are just tight enough, but still have a tiny bit of give.

I have one Mullard that isthe New Sensor RI labelled a 12AX7. I also have an OLD Mullard with the ECC83 on it. I haven't used it too often, but I'll get around to put it and a few RCAs and GEs through some playing.
 
Re: Tube review thread

Really good stuff so far.

My only recommendation is to include the amps you used while tube rolling. This way it'll give a better idea of how a certain brand/model/kind of amp responds to certain tubes.
 
Re: Tube review thread

Really good stuff so far.

My only recommendation is to include the amps you used while tube rolling. This way it'll give a better idea of how a certain brand/model/kind of amp responds to certain tubes.

That could take a while. Ive owned a few. ;)

Good idea, though. I was going for a general review of what Ive tried and used, but some detailed amp/tube combos would definitely be helpful too.
 
Re: Tube review thread

Could you please share the benefits of:
1. Utilizing an attenuator over changing tubes so that distortion kicks in around 3-4 instead of 6-7 volume level?
2. Continuing to use tubes that seem to distort around 6-7 (Fender Vibro-King) and instead rely upon effects pedal/box?
3. Other?

I also have a Fender Super-Sonic that includes two gain options that allow great break up at lower volumes. Our band has a Fender EC Twinolux that seems to be right in the middle (breaks up at maybe 4-5 on volume...nice!). My favorite is my Super-Sonic...........but with all the great reviews and comments regarding the Vibro-King I'd really appreciate tube advice and recommendations including adjusting the bias? Thanks!
 
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