tube watts vs solid state watts

Samuelaudio,

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.

db

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 Such presentations typically are not peer reviewed.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

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