How close to the real thing?

Fas42, assuming the goal for all equipment is as much accuracy as possible, I do lay the entire blame on speakers. Solid state electronics can be designed to be, for home audio purposes, perfectly neutral, in that their noise and distortions are inaudible, and their frequency responses are flat regardless of load.

Speakers, on the other hand, are usually "voiced" Sometimes this is because the designer wants to achieve a certain "sound", but they are also voiced to apply judgment of how much high frequency roll-off the designer wants to apply to make the speaker sound natural in a room with certain absorption assumptions. I suppose you could argue voicing in the bass might also be necessary, because of room variations.

The latest speakers, designed with the latest driver technology and sophisticated crossovers designed with the latest software, can produce awesomely flat frequency responses these days. The latest speaker designs seem to have frequency responses that remind me of curves we used to see for amps in the 1960's. (Distortion levels too.) But lots of speakers are still "voiced" to sound a certain way according to a designer's biases, and the best drivers and crossovers (and cabinets too) are actually very expensive, so a lot of high end speakers still have response curves that look like saddles (too much bass and too much treble), and compromised crossovers that produce anomalies at the crossover points.

The differences in solid state electronics are far smaller. With tube electronics, one can design them to be as neutral as SS types (VTL comes to mind), but things like SET amps will have nearly unpredictable interactions with a particular speaker.

I also tend to believe that practically, in most well thought out real world setups, that a higher % of those using SS amps will sound closer to the real thing to me.

I say this based on the fact that I hear more variations from what sounds rel to me more with tube gear I hear and use than with (good) SS rigs.

I suspect that Mapman is correct for reasons coming from the other side. I have been surprised how my new Tube guitar amp changes character depending on how long it has been on and such. If I can change the source based on tube temp? than it makes sense that a tube output system may display this as well?

Paulsax, if I don't leave my ss gear on 24/7 it takes at least an hour to sound its best. With the high cost of tubes and electricity, few leave their tube gear on.

Yes, feedback is somewhere in there. But there is correct feedback, and "bad" feedback! If feedback was inherently not good then no piece of recorded music could ever be made to sound good, since every recording device and studio is riddled with feedback design techniques and circuitry, going back to almost the very start of electronic recording.

This is incorrect. The Ampex 351 tape machine, used by both RCA and Mercury (and a host of others) has a zero-feedback recording circuit. Neumann microphones use small tube preamps which are zero feedback. I can go on but you get the point.

there is no way that well-designed solid state amplifiers "tend to have these higher odd orders all the time. This is one of the reasons they tend to sound hard or bright. Now its important to note that these harmonics do not have to be very distorted, usually 100th of a percent are audible, simply because these harmonics are so important to the human ear." Total harmonic distortion, meaning any and all spurious frequencies away from the fundamental, is normally at about -70db or better, usually better, and there's no way that such low-level distortions could possibly cause amps to sound hard and bright.

OK- you obviously understand how low the distortion levels are we are talking about. I think I did express that 100th of a percent is audible- seems like that needs more emphasis. Since we humans use the odd orders (5th, 7th and 9th) in order to determine how loud a sound is, obviously while the ear is not sensitive to *some* things, this is one thing that the ear is *very* sensitive to. BTW all of this has been known since the 60s and Norman Crowhurst was writing about this subject in the 1950s.

So this is indeed a way that explains why transistor amps can sound harsh while having otherwise flat frequency response. Note also that with many transistor amplifiers, as power output decreases there is a dip in distortion and then it rises again as power output continues to decrease. This is one of the reasons that low level detail is challenging for transistor designs.

It also points to the way to make transistors work as well as tubes, FWIW. I can point to several SS amp manufacturers that have been exploring zero feedback designs and some of them are as good as some of the best tube amps I have heard. Mind you this coming from a tube amplifier manufacturer...