What the specific test results that D. Edwards linked to tries to point out is that many ( NOT all !!! ) tubed designs typically sound "richer, fuller & airier" because they are generating TONS of harmonic distortion.
These harmonics tend to make "sparse" sounding digital recordings sound more natural, hence their ability to not only "warm things up" due to the aforementioned lack of bass control / current output, but also to "breath life into" these recordings. They do this through emphasizing all of the harmonic overtones that may / may not have been present originally.
If you look at the Halcro vs the Yamamoto's spectral content, the Halco produces the primary signal and is -100 dB's down by the second harmonic. The Yamamoto on the other hand, is only about -40 dB down. This means that the Yamamoto is producing 60 dB's more output than the Halco at this point, let alone WAY more output across the entire spectrum. It does this at any given time or amplitude. Bare in mind that the Halco is doing this at 100 watts of output whereas the Yamamoto is at a watt or less !!!
Quite honestly, this is NOT a very fair comparison, but it does make a point. Using a poorly designed and possibly misadjusted ( read the text ) SET tube amp to compare to a high negative feedback SS amp just isn't fair or right. Maybe as an example of what is possible on both extremes, but not as a general example. Most designs are going to be somewhere between these two extreme examples.
On top of that, i really don't think that anyone shopping for something along the lines of the tubed Yamamoto ( rated at 2 wpc ) is going to be comparing that to the Halcro. They are completely different design approaches producing very diffferent sounds and system compatability issues. Whereas the Yamamoto might sound "larger than life" due to all of the spurious harmonic distortions added, the Halcro tends to sound thin, sterile and lifeless. Most of that is probably due to use of too much negative feedback.
Whereas the Yamamoto is a prime example of why some people refer to tubed audio gear as "distortion generators", some would say that the Halcro is a prime example of why some categorize SS gear as being "unmusical, lifeless and sterile". While one could be said to be "more technically correct than the other, it all boils down to system synergy and personal preference. After all, the bottom line is building a system that you can listen to and enjoy the music without being fatigued, annoyed or distracted by the gear itself. Some do that with tubes, some do it with SS. Some use a combo of the two, looking for the "added harmonic richness" of tubes with the speed, focus and authority of SS. Whatever you choose to go with, just make sure of one thing. That is, it makes YOU happy, as YOU are the one that has to use and listen to YOUR audio investment : ) Sean
>
