tube watts vs solid state watts

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 Such presentations typically are not peer reviewed.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.

db

hi,

"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 Such presentations typically are not peer reviewed."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.

Larry

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.

db

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?

NOT!

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.