tube watts vs solid state watts

(newbie here)...Does a 60 tube watt amplifier produce the same perceived "loudness" as a 60 watt solid state amplifier with the same speaker/preamp level?
No, the tube sounds much louder in my experience. A a general rule tube amps sound about 30-50% louder then SS amps of the same spec output. This is a general rule. Some amps are speced lower than the actual output like Aloia SS amps and others. However, in general tubes amps play louder than SS amps with the same written watts spec.

There is no answer to your question, instead of worrying about specs. try and find an amplifier that will mate to you speakers well, synergize with your preamp/source and most importantly suits your listening preferences. The tube vs. ss watts debate has been argued adnauseam and there still is no conclusive answer. Some people prefer tubes(like myself) some prefer SS, I think the subconscious influences the perceived power of an amp more then if its tube or ss.
In agree with Tireguy in terms of how to buy an amp. But as a general answer to your direct question - tubes do play louder.

It's not that tubes play louder. They just present the midrange more upfront. 90DB through a tube amp and 90DB through a good solid state(everything else being the same) will sound totally different. In a SS system, the bass will be more fleshed out so, bass will move more air than mids so, it moves the SPL level up earlier and quicker than a tube amp will. The tube amp will be moving the air with more mids and less bass which in turn sounds louder cause it more midrange and less bass. I hope you get what I mean! Get a SPL meter and two amps( 1 ss,1 tube) and test it.
Tube watts sounding louder is an urban legend.
Loudness relates to Gain (Volts out per volt in), not to power rating which is simply the maximum that can be output without unacceptable distortion. A low power amp, perhaps a tube amp, with a high gain will play louder, for a given setting of the volume control, than a much more powerful amp with lower gain so long as the maximum power of the smaller amp is not exceeded.

A watt is voltage times current, regardless of whether the juice is generated by a tube amp, a solid state amp, a magnetic amp, or any other type you can think of.
Distortion sounds approximately 10 times (6-8dB) louder to the human ear than an undistorted signal at the same output, so the perceived "loudness" of an amplifier will be directly related to the amount of TH-distortion in the signal. Just look at Stereophile measurments for your answer. If the amplifier generates more signal (THD) then it is outputing more signal at the "same" wattage output.

Its really quite simple. The Halcro is the "quietest" amplifier of them all.

Speakers will do the same thing adding even more volume to the sound especially when the signal is already distorted, more THD the louder its perceived sound, its really quite logical if you think about it.
i think it all depend's on what amp's your comparing,some manufacturer's intentionally under rate their amp's wattage while other's rate their's right on the money.

there is no correct answer to your question.

It is true that the amp itself considering all its components has more to do with perceived power. A Tube amp rated at less than 30 watts for instance may have enormous trannies that will power your speakers to a high volume. That being said I find that many tube amps clip more easily when pushed versus high powered SS. I have not used low powered SS but have tubes (low watts can't be pushed without distortion) and 400 wpc ss amps which have tons of headroom. The real difference is the quality of sound not just the volume. The tube amp is more musical.
Perceived loudness aside, take care not to impose a loudspeaker/volume load on to a relatively underpowered tube amp such that it often is driven into clipping. Tube or ss, you still should properly match an amp to its load.
I think tube amps have 3 to 6db more headroom then ss amps at any given pwoer rating before serious levels of distortion become evident.


Your question is complicated by the term perceived loudness. Loudness is the preception of sound level. Had you asked do they vary in produced sound presssure level (SPL), that depends on the gain. One 60 watt amp might reach full level with a .5 volt input, another 1.5 volt, a case in point being the old Mac 60 and Dynaco 60. Obviously the Mac 60 had much higher gain. It also depends on how well the amp matches the impedance characteristics of the speaker. Some speakers are notorious for dipping down to very low impedances at certain frequencies.

Loudness, OTH, has many characteristics. Distortion is a main component, so even a moderate SPL can seem loud, just visit the "HIFI" room of most Circuit City stores. In so far as tube amps might be more prone to introduce distortions, e.g. tube microphonics, they can indeed sound louder for a given input.

I'd agree that tubes seem to put out more power than SS given the same output rating. But I think this has something to do with the way tubes clip and distort vs. the way SS clips and distorts. I think the latter is much more difficult to endure, whereas tubes tend to clip much 'softer' if you will. On a scope the difference is that between a gradual sloping curve and a dramatic, Wiley Coyote cliff, dropping off into an abyss of ear-piercing distortion. (Can you tell I prefer tubes?). The bottom line is that for the same power amp you may be able to push the tubes louder without perceiving (being bothered by) the distrotion/clipping that is actually ocurring.

I am not so concerned with the location of the volume knob or which amp gives more volume on a given setting. That of coarse is dependent on the gain of the amp and the matching between the two components.

I have experienced over and over that tubes amps just simply play louder per watt of rating. I am not a tech guy but know what I have experienced playing with perhaps 15-20 SS and tube amps in my home.

One other thing I have noticed. I love both SS and tube amps and will always have one of each on hand. My ears find that SS amps fire the sound out of the speakers more than tube amps. They attack the listening position more. Tube amps seem to float the sound out of the speakers more. Again, this is something I have found to be generally true. The one exception was my Mac MC402 amp which did not fire out the sound like most SS amps but floated it out. Just like the reviewer said " it was the best tube amp I have ever heard".
It seems to me that there are low, or lower, watt tube amps paired with speakers that one generally would never dream of doing with the same watt ss amp.
Watts is watts! But since you can drive most tube amps well past clipping (into serious distortion) without hurting your speakers, many tube users routinely clip their amps to high distortion levels to get a little extra volume.

If you do that with a solid-state amp, the odd-order harmonic distortion will grate on your ears, and you'll likely burn out your speaker's tweeters. This is why solid-state users prefer to use amps with more than enough power to get the job done, while tube users take advantage of the tube's soft clipping nature and many times use an amp that is way underpowered to drive their speakers. I guess they don't mind/notice the compression, and they welcome the extra fuzziness of the distortion.

And I don't know of any tube amps that have 3 to 6dB of headroom. Actually, not too many amps of any type have that much headroom.
My tube amp goes to "11"!!!

marco,i shudder to think what the 11" reference is about.
Of all the amps I've owned tube and solid state, multiple of each, I've yet to hear that a tube amp sounds louder than solid state. I've concluded that if you like your music dynamic like in real life, it takes some power to do that.
11"? = 11 o'clock What do YOU have your mind, big guy? lol....
When comparing solid state or tube amps, be aware that the rated output is based on impedance. Speakers vary greatly in both impedance and efficiency, making this a difficult decision to make if looking at specifications without every fact revealed.

What follows is a perfect example of how output power ratings can be confusing to the buyer after auditioning and not getting the results they expected.

Compare a large solid state amp rated at 1000 watts compared to a 200 watt Atma-Sphere OTL. For the speaker, an early (1990) pair of A-1 Sound-Lab.

The 1000 watt solid state amp drops to about 75 watts at the most difficult to drive bass frequencies (80 HZ and below) as the impedance rises to 56 ohms (+). The Atma-Sphere MA-2 OTL will produce more than 200 watts into that same difficult load.

The Atma-Sphere will have problems with that same speaker at 22K because the load is now 2 Ohms, but since there is so little music at 22K it becomes irrelevant. The outcome is the 1000 watt amp is clipping much of the time and the Atma-Sphere will drive the paint off the wall.

The listener is confused, why more volume with 200 watts than 1000? The problem begins with most speakers impedance being listed as "nominal." The actual full bandwidth impedance is seldom revealed.

Some speaker designs are extremely low impedance (below 2 ohms) and other vary at different points in the frequency spectrum. Yet another reason to choose an amp design that's sound appeals (transistor or tube) and try it in YOUR system with YOUR speakers to see if the combo flies.
In my opinion Tube amps appear to so a better job of driving a load than most average solid state amps and thus may appear "louder". In addition most tube amps like my Audio Research VT60SE are so beautifully made and include such heavy metal power supplies etc, that they tend to sound more powerful.
You boys are filthy, filthy, filthy! Minds in the gutter at all times eh? The reference was to the movie "Spinal Tap"...I guess no one's seen it!? Y'all should be ashamed. This is a public forum after all!

This is a public forum after all!
Marco, I hate to red pen you, but did you intend to include the L in "public"? After all, if yours goes to 11...
Actually, most tube amps run into difficulty driving low impedance loads and put out less power at 4 and 2 ohms than most equivalent solid-state designs (many of which double power into 4 ohms and then double again into 2 ohms). So if you have a well designed ss amp rated at 50Wpc into 8 ohms it could put out 100Wpc into 4ohms and up to 200Wpc into 2ohms. A typical tube amp rated at 50Wpc will put out nearly the same 50Wpc at 4ohms and much less power (maybe 25 watts) at 2 ohms. That said, a few tube amps are specifically designed to drive low-impedance loads more efficiently. I believe that VTL has a few models optimized to drive 4-ohm loads.

Additionally, tube amps traditionally have terrible damping factors which is why their bass is loose and indistinct compared to decent solid-state.
The clipping characteristics of tube and ss amps do differ, and tubes do sound less harsh and do less harm to tweeters. However, except in Pro sound applications, anyone who, on a regular basis, drives their amps into clipping is simply using the wrong amp. Solid state amps can have circuitry that detects when clipping is on the verge of happening, and prevents it by a gain reduction. Of course this is compression, but at extreme volume level it is scarcely noticeable, and sure is better than clipping. Pro sound amps are most likely to have this feature, because these amps are often used right up to their power ratings, and with live sources that can not be preauditioned to set gain. I am using CarverPro digital amps, 600 wpc at 4 ohms, that have clip detection, and I have this feature switched on. Much to my surprise I discovered that my Maggie 1.6 speakers, 4 ohms, can trip the clip limiter feature if I play certain music at too high a volume level.

"d" minor - saddest of all keys.

interesting paper about tubes vs transistors here

The "paper" by Russel Hamm appears to be a presentation at a session of the AES nearly 13 years ago. Such presentations typically are not peer reviewed. The questions following a presentation can be a form of peer review. The presenter appears to have connections with a manufacturer of tube amplifiers. Were it a peer reviewed article, I suspect the premise of the study, driving equipment beyond its operating range, might have been questioned and caveates added to the generalizations. Furthermore the confusion of the "loudness" of a trumpet with its SPL should have been corrected. Finally, why study the attacks of synthesized instruments rather than the instruments themselves?

Bottom line: This is not a peer reviewed article, but a presentation in front of a session of a technical society by someone with commercial connections that give the appearnce of a conflict of interest. I have seen presentations where there were only a few people in the audience, other presentations where the questions were embarassing and/or contentious -- I chaired a session that had one such presentation. As chairman, you're faced with a dilemma: Do you hold to schedule for the convenience of those who jump from session to session or do you permit extended discussion that is the reason for live presentations? You'll make enemies in either case.


"The "paper" by Russel Hamm appears to be a presentation at a session of the AES nearly 13 years ago. Such presentations typically are not peer reviewed."

I don't think you know that for a fact. I've presented papers before various orginizations and they were all peer reviewed before I was allowed to present them.

I doubt your presentations were really peer reviewed, Larry. Abstracts usually are submitted to a program chairman who chooses among the submissions for inclusion in the various sessions in the chairman's area of expertise, but this is not the same as peer review, except in so far if the chairman thinks the presentation is likely to be without merit it can be rejected. Presentions are less formal, and count for much less in a resume, than peer reviewed articles. After all, presentations are usually in the nature of breaking results or progress reports. I'm not expert in most of the areas addressed by the Hamm presentation, but I'm skeptical of considering it as authoritative. One bother is the appearance of a conflict of interest; another is the careless terminology.

Finally, and I realize this seems elitist, I don't expect presentations by a person with such modest academic credentials, although I admit that graduate students often present their first paper at such a conference. My initiation was as a graduate student at the formidable Rackham Auditorium at U. Michigan in Ann Arbor.

Hello all. My god we've got a professor type in our midst. Happy xmas professor don. be "authorative". For my part I'm sitting in a 12'x12' room with low ceilings, listening to 7W of SET tube power driving my Quad ESL 57's to excellent levels of volume without distortion that i can hear. I have had Leak tl12+s (12W tubes) doing the same in a 20'x20' room. My experience of larger 50W of ss is that it doesnt necessarily do any better. more of that ss attack and power, but at the expense of the 'magic'. I've also owned a lentek 100w ss amp that was a bit limp in all respects despite its reputation as a Naim-beater. I am suitably confused, and agree totally with Albert that one can only put it in your system in your room and see what happens.
Watt's are Watt's period. As for tube vs ss with concern for dynamic headroom, heh, the guy that said tubes have 3 to 6 dB more head room is quite incorrect.

Tubes DO NOT scale on the power curve as SS amps do, why? Because they are non-linear, that is they only reproduce a particular scale of harmonics, hence the "tube sound".

Tubes are only as good as two factors, the tubes in use and the PSU (given a good circut design). But then the same similarities can be said about SS gear.

Ask yourself what the holy grail of tube gear is? BASS responce- now again ask yourself why this is? Now, unless your running some very efficient speaker system, SS does a much better job of reproducing the SOURCE when one considers the speaker system, which is far more important then the amplifer (any design) by any means (given equal quality to amplification).

Try running tubes on four or two ohms at full power for a full cd or record with heavey meatal music, lol g/l, I hope you have spare tubes handy when time consumes and degradates your tubes into useless glass speakeasy's.

Point is this, the sound- good tubes sound good with efficient speakers, but they are terrible at driving low impedence loads (a highly "dynamic" loudspeaker of good design). But there is one very important thing many tube heads ignore- TRUE dynamic range, I wonder does any speaker consistantly remain at 4, 8, or 16 Ohms- EVER?


An empty tube equates to what?

Oh and BTW, one of the premire tube gear makers told me this on the phone this very night.

Think on that.
Sounds like Alpha 03 is in the SS camp.
People go on and on about one brand of tube vs another, but I think that it is the audio output transformer which largely determines the sonic quality of a tube amp. It's not easy to "roll" transformers so there is little discussion of this subject.

The early success of Dyna Kit (later known as Dynaco) was due to the fact that before they designed and sold amplifier kits they were a manufacturer of top notch transformers.
Alpha 03, while tube amps may not be able to increase power into lower impedances, solid state amps will decrease power into higher impedances. Some speakers actually do maintain a relatively stable load. Try running a 16 Ohm speaker with most solid state amps. I think the previous posters got it right. Tubes usually clip more gracefully. Solid state usually can offer more power less expensively. Your choice of speakers and to some extent up line components may have a large influence on amp choices. BTW, I'm more of a ss amp kinda guy.