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-   -   Everything you ever wanted to know about TUBES! (http://www.ultimate-guitar.com/forum/showthread.php?t=473149)

Roc8995 11-26-2006 12:19 AM

Everything you ever wanted to know about TUBES! (For gear thread maybe?)
 
As requested, here's a list of various tubes and their various characteristics. I'll stick with what I know, and others can chime in as they feel necessary. I'll add the comments to this master list if they're worthy. If popular consensus goes against my experience, I'll change mine in favor of the masses.


*Keep in mind that these are my opinions and should only serve as a very general guide. Tubes are an art, not a science, and a tube I hate may be something you love. Your results may vary.*

Current Production Tubes:

Preamp Tubes:

12AX7/12AX7A/7025/ECC83/CV4004 (Different names, same tube):

JJECC83-S:
A good preamp tube, a bit dark. They're well made. They are higher gain than most 12AX7s.

Tung-Sol 12AX7:
These are excellent tubes. They sound very balanced and open. They are especially good in the microphonics department. DO NOT use them in a cathode follower stage! They will die. If you don't know if your amp has a cathode follower stage, ask before you put a tung-sol in.

E-H 12AX7:
These are decent tubes that seem to last a while. They're a little smoother than the Tung-sol. They will exhibit a small treble spike in some amps.

Sovtek 12AX7-LPS:
These tubes sound "just ok." They're cheap and durable and are perfect for reverb drivers and phase inverters in high-gain amps. Like the Tung-sols, they should not be used in cathode followers.

5751:
Sovtek: Finally, Sovtek makes a good tube. It's a bit bright, but not harsh. A good choice for taming Fender amps that are too aggressive higher up on the volume control.


12AT7/ECC81:

E-H:
A solid tube, good if you want to get rid of some hiss from your amp or lower the gain by replacing a 12AX7. Very quiet and even. I like these.

JJ:
Suffers from the JJ preamp disease: It's too dark. Construction's ok, but nothing to write home about. Just an all right tube.

Production Power Tubes:

EL-34:

JJ: Far and away the best EL-34 you can get without paying an arm and a leg. Higher gain than most, and a tad dark, but very articulate. Sweet.

Sovtek:
Not a bad tube. They sound weaker than a JJ, and bright. Not a good choice for Marshalls.

E-H:
Very close to the JJ in durability and microphonics, and a good balanced tube as far as tone. Great if a JJ is too dark for you.

Groove Tubes (GT rebrands its preamp tubes but makes its own power tubes):
"very nice tube, long lasting but have a alightly harsh tone to them. great headroom, and add an overdrive..incredible crunch. compared to jj's el34L, they had a tab less headroom, and i prefer the jj's distorted tone better, its more agressive and tones down better." Thanks to godofshred for that review.


6L6:


Tung-Sol: Bright, round and smooth, they get the thumbs-up for bassman style amps.

JJ: Darker than the Tung-sol, these are also very nice tubes with a warmer OD. Twin Reverb and Hot Rod deluxe people like these.

Sovtek:
There are two versions, can't remember which one I tested. They're dead quiet, but the tone suffers badly from it. They sound pretty lifeless.

E-H:
Not as quiet as a Sovtek but the tone is much better. Sounded a tad dark, which is good as they mostly are used in over-bright Fender amps.

6V6:
Tung-Sol:
An excellent tube. Very smooth and buttery. Sounds great in Deluxe reverb-type amps. No problems with microphonics.

JJ:
Both this and the Tung-Sol are great choices for a 6v6. A bit darker and more aggressive than the Tung-Sol. Again, no worries with noise.

E-H:
Not a bad tube, but painfully mediocre in comparison to the JJ and Tung-Sol.

EL84:

JJ:
Sparkly, aggessive, chimy, and awesome. Everything an EL-84 should be. Seems to be better than others as far as hiss goes, but almost all EL-84 amps have some small white noise going on. Very well constructed. Treat your AC30 to four of these!

EH:
They sound decent, but don't have the harmonic content or definition of the JJs. Generally good as far as durability.

Sovtek:
Uninspiring and generally noisy. This is probably what came with your amp. Throw them away.


NOS Tubes:

I have not tried enough NOS Power tubes to give a good comparison. These NOS Preamp tubes range a lot in price, but none of them are cheap. However, expect them to last much, much longer than any current-production preamp tube. They should be good for at least 10 years. They all sound amazing as well.

12AX7:
Telefunken: These tubes will last you 30 years. For real. They sound very hi-fi and are perfect for your clean channel. Great in Voxy amps. They aren't for everyone though. I would not put these in a Fender twin. They will make any amp incredibly articulate, so all you high-gainers take note!

RFT:
Dark and smooth. Perfect for Marshalls that are a touch too trebly. Not a good choice for darker-voiced amps, as they will get muddy.

Mullard: "Agressive but quiet, really livens up the amp. Adds sizzle and 'oomph.'" - Thanks to godofshred for that one.

RCA:
Balanced and warm. No microphonics. All-around good tube. Worth the price.

12AT7:
RCA: Same as their 12AX7, with a bit less gain.

Mullard: Very cool, a 3-D sounding tube that's not real expensive and will last forever. Very warm, tight bass.

Here are some more reviews courtesy of darkarbiter:
Sovtek KT66:
Bright and chimey when clean, but has a weak low end and overdrives harshly.

Philips 5751:
Smooth highs, and solid lows. Good for smoothing out an amp with a harsher top end, and to get less gain from the preamp section.

RCA 12AU7:
Smooth and warm with low noise and microphonics.

Groove Tube 12AX7:
Kind of harsh and brittle, not very musical. Works good as a tremolo tube to get a choppier, more agressive tremolo effect, though. Roc edit: groove tube 12AX7s are usually rebranded Sovteks, so this review is consistent with my previous estimation of that tube.

Groove Tube 12AU7:
Same goes for the 12AX7, but sounds decent as a phase inverter when you want low gain.

THUS ENDS PART ONE. Scroll down for part 2.

friedxrice 11-26-2006 12:21 AM

'scuse me, but what does "microphonic" exactly mean?

And I nominate a sticky for this thread. Or atleast a merge into one of those other stickies.

Roc8995 11-26-2006 12:23 AM

'Microphonic' means that a tube, usually a preamp tube, starts to pick up noise from outside. All tubes are microphonic to a degree, but too much is a bad thing and will make your amp very noisy and unpleasant.

Part II-


*THIS JUST IN*
Gabel posted this in a different thread, and I'm going to reproduce it in its entirety here, because it's something a lot of people don't think about when looking at amps. He also plays an ebony Les Paul, the official instrument of tube-savvy UGers.

Quote:
To start with I'm going to talk about some terms I will use here. The first is distortion, which in this text ALWAYS will mean power amp distortion. The second is headroom, which is how long the amp stays clean.

Alright we will start with a basic thing. A general rule of thumb is that a tube amp is 2,5 as loud as an SS amp of the same wattage. So take a standard 50 watt amp which is equal to a 125 watt SS amp. So far so good. But this is were it gets complicated.

To start with a 50 watt amp is always a 50 watt amp, no matter if it's tube or SS. So how can a tube have more power then? It doesn't. What it does though is that tubes can cover frequencies and pick up harmonics that SS amps just can't. This is why a tube amp sounds louder, because to our ears it appears louder. Secondly a tube amp sounds "fuller" in tone, compared to an SS amp.

But then comes another thing which is measurment of wattage. When you measure wattage you DON'T measure the max output of the amp. The measurment of wattage is in RMS, which means max output of wattage BEFORE distortion. So that means a 50 watt amp (both tube or SS) is pushing out 50 watts before distortion. But it doesn't end there.

The thing is that when an SS amp is pushed into distortion it sounds horrible, awful and muddy. People want high headroom with SS amps, which is the reason we have a 550 Fender Metalhead. With tube amps you generally WANT distortion. Makers knows that and actually constructs the amps to start distorting. But as I said you measure watts in RMS. But what happens when the amp distorts? It pushes out more wattage of course! Take an Orange Rockerverb 50. It's rated at 50 watt RMS, but the max out it 90 WATTS!

Let's take and compare it to an SS amp. An SS amp equal to the amp clean would be rated 125 watts. But when the amp starts to distort, it's pushing out more power and 225 watts is equal to 90 watts of power. That's quite a difference.
The thing with tube amps to is that the more you turn it up the louder it is. With an SS amp you DON'T want to turn it up, but with a tube amp you WANT to turn it up. So what would be the loudest? A 100 watt Marshall MG (SS) or a 30 watt Vox AC30 (tube). The AC30. Why? Well when you turn up the MG it will sound horrible, so you want to keep it low. And when you turn up the Vox it sounds better, meaning it pushes out more power, so its pushing out more than 30 watts.

Let's do a comparisson. The British show Top Gear once did a race with a Lotus Exige S and a Ford Mustang GT. The Lotus had a 220 horsepower, 1.8 liter, 4 cylinder engine. The Mustang had a 500 horsepower, 5,8 liter, V8 engine. So who won? The obvious winner would be the Mustang.

But what car won?

The Lotus by far. Why? The car was lighter and therefore you could brake later, it accelrated a lot faster, because of the low weight and you could get out of the corners quicker. It's kind of the same with tube amps and SS amps. The tube amps might not appear as powerful the naked eye, but can be a lot more powerful than you think.

Tube wattage chart:
1 x EL84≈ 5 watts in Class A
2x EL84s≈ 15 watts in Class A/B
4x EL84s≈ 30 watts in A/B
6x EL84s≈ 45 watts

1x 6V6≈ 10 watts in Class A
2x 6V6s≈ 20 watts in Class A/B
4x 6V6≈ 50 watts in Class A/B

1x EL34/ 6L6≈ 15 watts in Class A
2x EL34s/ 6L6≈ 30 watts in Class A, 50 watts in Class A/B
4x EL34s/ 6L6≈ 100 watts in Class A/B
6x EL34s/ 6L6≈ 150 watts in Class A/B

1x 6550≈ 20 watts in Class A
2x 6550s≈ 50-70 watts in Class A/B
4x 6550s≈ 100-120 watts in Class A/B
6x 6550s≈ 150- 200 watts in Class A/B

When speaking of KT tubes, KT-66s is based of a 6L6, KT-77 of an EL34 and KT-88 of a 6550.

That was all, hope you enjoyed the reading
Gabe



So that's it!
For more information, you can go to any of these sites:
www.kcanostubes.com <Check out the 'Reference' Section, tons of stuff in there.
www.thetubestore.com
www.tubedepot.com


FOR INFORMATION ABOUT BIASING, TUBE COMPATABILITY, AND SUCH, VISIT A SITE ABOVE.
There are so many different types of amps and tubes that it would be impossible to cover all of that here. Plus, it's been done already on those sites.

jj1565 11-26-2006 12:31 AM

nice post. worth adding to the amp sticky. :cheers:

Gutch220 11-26-2006 12:35 AM

that must have taken a while to do, but its too cut and dry. I think a lot of people will take that information as "written in concrete" and assume anything else is blasphemous. Many things dealing with tubes are subjective

Roc8995 11-26-2006 12:37 AM

I'll add a disclaimer. Thanks for the input.

bluespunkmetal 11-26-2006 12:41 AM

Ruby ?? Svetlana ?? MEsa ??

Erock503 11-26-2006 12:47 AM

Cool post. I haven't had the same experience with JJ preamp tubes though. Microphonic to me is a bad tube. I actually thought the EH were a little noisier preamp tubes, at least the sets I've owned.

Roc8995 11-26-2006 12:47 AM

Quote:
Originally Posted by bluespunkmetal
Ruby ?? Svetlana ?? MEsa ??


Ruby and Mesa are just rebranded tubes, so I didn't list them here because they don't make their own tubes and it would be reduntant.

I have not had much experience with Svets, other than their EF86, which is a great tube, but so few amps use it I didn't think it would be worth putting up. I have heard their 12AX7 is incredible but haven't got my hands on one yet.

Rock Savior 11-26-2006 12:48 AM

Sticky!!

good work Roc!!

Roc8995 11-26-2006 12:50 AM

Quote:
Originally Posted by Erock503
Cool post. I haven't had the same experience with JJ preamp tubes though. Microphonic to me is a bad tube. I actually thought the EH were a little noisier preamp tubes, at least the sets I've owned.


There are two kinds of noise that come from tubes, microphonics and 'mechanical' noise. I didn't do a good job of discerning between the two. The EHs have a bit more mechanical noise (noisier in general), while the JJs go microphonic- that is, they are pretty quiet until they go bad. What I should have said is that the JJs are quiet mechanically but fail every once in a while.

bluespunkmetal 11-26-2006 12:56 AM

Nice... Thanks for the response....

Erock503 11-26-2006 01:11 AM

Quote:
Originally Posted by Roc8995
There are two kinds of noise that come from tubes, microphonics and 'mechanical' noise. I didn't do a good job of discerning between the two. The EHs have a bit more mechanical noise (noisier in general), while the JJs go microphonic- that is, they are pretty quiet until they go bad. What I should have said is that the JJs are quiet mechanically but fail every once in a while.

IC, I'll have to keep that in mind, I didn't realize they were known to have a higher failure rate than other preamp tubes. That's not good, because I actually like their tone lot in my amp. I've been lucky with mine so far I guess, the only ones I've had actually fail on me are Mesa's and GT, however both were already in amps when I got them so they weren't new. I've only been using JJ preamp tubes for about 8 months though.

aznrockerdude 11-26-2006 01:33 AM

This should definitely be stickied.

forsaknazrael 11-26-2006 01:35 AM

This is exactly the kind of information I've been looking for. You rule, Roc.

aznrockerdude 11-26-2006 01:48 AM

Wait, what about Groove tubes?

Roc8995 11-26-2006 02:31 AM

Quote:
Originally Posted by aznrockerdude
Wait, what about Groove tubes?


Groove tubes are just rebranded tubes. The problem is, they rebrand every kind of tube (JJ, Sovtek, Chinese crap, etc) so there's no way of knowing what you're going to get.

bluespunkmetal 11-26-2006 03:49 AM

Wait......... how do they rebrand a tube ??

Just peel the paint off ??

Wiro 11-26-2006 10:39 AM

Very nice Thread, very usefull!

Dave_Mc 11-26-2006 11:25 AM

nice post. I have no idea on the accuracy of it, lol, but assuming everyone else thinks it's good, i'd definitely second it for a merging into the stickies.


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