Tube amps have a signature sound

I've been listening to live music as a sound tech/engineer since the late 70's. My experience has paralleled that of the reviewers in Stereophile, The Absolute Sound, FI, and most other "high-end" rags. Tubed equipment just sounds more like live music than SS. Of course there are tubes that impart colorations(microphonics, sugar coating/glaze, tubbiness, British sound, etc.), and tubes that just convey the truth(usually NOS and German or American). That's why so many of us(tube/musical truth lovers) spend so much time "tasting" so many different tubes. I've got a VK-D5 CD player and a pair of Cary SLM-100s. I've lost count of the tubes tested/rejected before settling on six Siemens CCa's(from the 60's) for the BAT, and the TungSol round plate VT-231s(40's), Sylvania 6SN7W tall bottles(40's), and Winged 'C' 6550's(latest iteration) in my Carys. I'm bi-amping with SS for the bottom because it's just easier to get good/fast bass with solid state. I'm using planar speakers for mains, and a subwoofer sytem has to be fast to seamlessly blend with them. You and I will probably have started a major controversy with your question and my response. Don't be confused by all the opinions you'll get in here. Read what the experts have to say(those not swayed by advertising dollars and that are familiar with live music), you'll find that the highest rated equipment is invariably tubed and SS is usually compared to and judged by how close it gets to that standard. BOY- is THAT statement ever inflammatory!!

Odd ordered harmonics have absolutely nothing to do with loudness or SPLs.( http://www.thewhippinpost.co.uk/glossary-H-M.htm) (http://www.hometheaterhifi.com/primers/the-primers/negative-feedback.html) They WILL give you a massive headache however. Both of the above sites contain definitions of odd-order harmonics. The only correlation between them and loudness is that overdriving a solid state amp produces much more, and overdriving a speaker system can cause a lot of intermodulation and/or saturation of the crossover. One of the reasons amps sound more accurate now days is that the components(capacitors, resistors, even wire) used in manufacture have been vastly improved upon. Unfortunatly the TUBE manufacturers have not been keeping up. The tubes made in the 40's through the 60's are still the most lucid/transparent/accurate on the whole. As I stated earlier: Read what the experts that use LIVE MUSIC as a standard(both amplified and acoustic) have to say on the issue. Become very familiar with live music yourself, then judge the accuracy/staging/imaging/sound pressure levels of your system accordingly. Of course: everyone's goal isn't the same. Some folks are happy to have their eyes tickled. If everyone had the same tastes; this would be a very boring world. If I can't close my eyes and pretend I'm at the original recording venue(NOT the band playing in MY room, and not all recordings contain enough encoded info to allow this), it's hard for me to even tap my foot.

My contention here would be that the square wave, being an irritant and obnoxious to the listener, might be PERCEIVED as louder. Same reason most people would get "listener fatigue" sitting in front of a system with a lot of IM distortion. Ah- OK: "loudness cue", not actual loudness?(just re-read your post) Not that the sine wave and square wave would deflect an SPL meter to different levels at the same power, but that the square wave would be perceived to be louder? Are we saying the same thing here? I'm REALLY not intentionally being obtuse....Honest!

That's funny: I always thought of the top and bottom of the waveform being flat as DC(simplest terms), as in while a SS amplifier is clipping. Ya learn something new every day

That's funny- On my system I can discern the silk of Zildjian cymbals from the brassiness of Sabians(for instance). My guess would be that you've never heard a properly tweeked tube system(could have been the cables, the tubes, the source(who knows?). How I wish I could be happy with a SS system. SO MUCH cheaper and easier to live with!!

Bigkidz- I've been doing that for the past 18 years(and bi-amping in general since 1981). Need any tips?

And that's why tube amps seem to play more loudly than SS of the same power rating(without giving the listener a headache)- soft clipping. You're preaching to the choir. One day(if I win the Lotto) perhaps I'll be able to afford to go OTL. Of course my listening room gets quite warm in the summer with no more tubes than I have in the system now. ALAS- champagne taste and a beer budget!!

Bigkidz- If you bi-amp correctly, you'll never go back. For instance, read this: (http://www.avguide.com/products/product-1672/) Click on the review. I'd been using a Dahlquist DQLP-1(slightly modded over the years) since 1981 with great results. The time-alignment that the TacT provided took everything to a whole new level, and still proved as transparent as the Placette Passive Linestage I'd used last with the Dahlquist.