I think I described the situation pretty well in my long winded post, but I'll try to 'splain further.

First of all, this whole exchange came about because of a post by Hoots, who also has very efficient speakers. Not as efficient as mine, but more efficient than 'normal'. I gave him my recommendation that he keep his lower power amp to drive them, as it probably has enough power for the job.

The post was really directed at those crazies like me who have really sensitive speakers: then Smart Little Lena (bless her heart) picked up on the post and a thread-fest ensued. If you had ever seen my setup, you would know that it is not even remotely typical of what a sane person would do, but that's just me

So, the bottom line is that it simply does not applly to most of everybody else out there: they have components that are matched pretty well, not to worry!

Now to answer your question on how much "grunge" is too much, well, the short answer is that ANY solid state push-pull amplifier on speakers as sensitive as mine will sound really bad. It's that noticable. The "grundge" floor is not a "constant" that you can measure, as I was specifically seperating out crossover distortion as a main culprit. Not the only one, but the most significant one in this situation. This is a dynamic function, not a static one: it is essentially being modulated by the audio signal.

In a typical solid state amplifier, there is a standing bias current that is flowing through the output stage at all times. If the signal stays within this amount of current, the output stage is operating essentially class "A" push-pull. At the point where the signal JUST TRANSITIONS from class "A" to class "A/B", one transistor is cutting off, and another one is taking over in the push-pull output stage (the other transistor has been conducting since just before the 'zero' transition). This is where that crossover distortion "grundge" resides. This class "A" window is exceedingly narrow in a typical solid state amplifier. Unfortunately, this also occurs right at a point where the program material is soft, and the distortion is not swamped by the signal in speakers with sensitivities as high as mine.

The more bias current that flows, the broader this class "A" area is, before it transitions from the 'positive' set of output transistors to the 'negative' set of output transistors. The catch is that the more bias current that flows, the more static heat is generated. High end stereo solid state amps tend to have a very broad transitional area. Therefore, they have to have huge heatsinks to dissipate the heat, and this costs money.

Anyway, normally this not as bad as it sounds, since this form of distortion is reduced by the negative feedback that all such amplifiers have. With speakers such as mine, it can't be reduced enough to not to be audible.

I don't know if you caught it in a post I had later in this thread, but I get around the problem entirely with the use of a single-ended triode tube amplifier for my high frequency horns, 1,200Hz and above. A single ended amplifier has a single output device, and operates in pure class "A" all the time. The micro-transitional effects of crossover distortion are avoided simply because there is no transition from one device to another. One output tube: very simple and basic. There is also no global negative feedback. Therefore a lot of potential problems are just side steped by the use of this amp for high frequencies. For the woofer, I use a 50 watt traditional class "A/B" tube ampilifier. This tube amplifier, in common with all tube amps, has a very broad transitional area between the time it is operating in class "A" push-pull and when it goes into class "A/B". Since these woofers are quite sensitive, I am not usually getting out of this class "A" area under normal listening conditions. For those occasions when more power is required, the crossover distortion is way below the signal level.

I hope this gives you the information you need!

[This message has been edited by soundhound (edited January 26, 2003).]