A tubes vs. Solid State question.

Hi Nrchy, even ordered harmonics are harmonics where the fundamental frequency has been multiplied by an even number, 2,4 and the like. 'Times 2' yields the '2nd harmonic' and so on.

Odd orders are fundamentals multiplied by odd numbers, 3,5 and so on.

This is probably more than you expected to hear from me about this :) but:

There is something extremely interesting about harmonic distortion, that no person can escape: the ear/brain system evolved to use odd-ordered harmonics as a loudness cue, as it is a very efficient means to analyze loudness without having to use all the cognitive facilities.

If you think about it, before (and after, FWIW) the beginning of civilization, quite often loud sounds were associated with extreme danger, thus the detection of how *loud* these sounds are is quite important and might need to be acted on immediately (as in 'fight or flight' behaviour). IOW the response to odd ordered harmonics can connect directly to the amygdala, the so-called 'reptilian' or 'lower' brain.

If you ever wondered how music and its reproduction can invoke an emotional response you need look no further!

What we can conclude from this is that odd-ordered harmonics at the very least induce stress, and indeed, tests GE performed in the 1960s showed that humans are quite intolerent of vanishingly small amounts of odd-ordered harmonic content.

So in simple terms tube amplifiers in good condition will be less stressful to listen to, as in general, they produce less odd-ordered distortion. Because the cerebral cortex can overcome messages from the lower brain, it is possible to still enjoy a transistor amplifier, but it will always been seen that a properly operating tube amplifier will be less stressful.

Reduction of this type of distortion was thus a paramount design goal with the Atma-Sphere lineup, as I was interested in getting the equipment to conform as closely as possible to the rules used by the ear/brain system. You might say this is a more 'organic' approach, and some designers feel that it is better to conform to the rules of linearity instead. I feel that in doing so this allows for small amounts of odd ordered harmonic continue to be ignored.

We are a long way from using all the ear/brain rules in audio reproduction. Just for example, we use linear recording and playback systems, yet the ear/brain system is logarithmic. It will be a while before anyone attempts that!

The explanation about odd-harmonics being perceived as bad by humans is probably a lot simpler than Atmasphere's explanation. In the beginning, before electronics, the only harmonics that anything (except bagpipes, of course)could produce were even harmonics of its root vibration because that is the nature of vibrating bodies and sound and the nature of human hearing.
Old mechanical alarm clocks had to sound much more loudly than present electronic alarm clocks, because the old clocks produced a base tone with even harmonics due to its inherent vibrating nature, therefore the sound being more pleasing, while electronic alarm clocks produce (purposely) a base tone with odd harmonics (or dissonant chords), therefore the sound being more annoying, thus not needing to be as loud.
Salut, Bob P.

Well, with the above science being used in this topic I will say this, as science goes its all theory until something else comes along, nothing is set in stone. But, from the above explanation, conditioning is the culprit, not true physical characters, that is to say- mental conditioning has caused this, not human DNA. I believe we as humans have evolved beyond this "flee or fight" factor.

Vinyl, as vinyl goes, brings with it many problems that the digital world needs not contend with. Possibly I am biased because I have only owned 1 or 2 decent TT's in my life and the rumble and hum at high output levels created a severe dis-like for such sources and their inherent problems.

Another words, for me digital is far simpler, and when done correctly, very close to the truth, as close as any analog source I have ever listened to. However, NO matter the source, there is an inherent loss regarding ANY recorded sound. There fore, one can only be better than the other in accordance to the listener’s preference- nothing more, thus making this conversation mute.

But for me, music is meant to be an enjoyable experience, one that is simple by its very nature, and one that can be reproduced at REAL levels w/o inherent problems and conditions that require extravagant means to reproduce such music.

When driven too hard tube amps do not clip much to the ear, but are out of steam, well done solid state which in my opinion will always use Bi-polar or Jfet type transistors can do this just about as well, and still have Slam factor to wake the dead keeping characteristics of non-fatiging music and highs, of course backed by digital or analog capable of this in the first place. Mosfet has never seemed to work for this in my experiance so I stay away, whoever said that mosfet is more tubelike is wrong in my opinion, however Mosfet used in a Hybrid amplifier design with the inputs rounded off by tubes in the first place can work well. So for me Hybrid systems are the best, Via Tube Preamp, with excellent solid state amps, or using a hybrid Amp or Intergrated could have similar results. Tube amps in the end for me are too much hassel, too costly, to much to re-tube, and too much heat for things that in fact can be very closley matched with tube solid state combo's that will get you 99% of the way there with reliability on top of that.

Matrix, do you think that Mosfets are compromising Pass designs?