Guitar Amps versus Monoblocs?

As noted above frequency range and distoriton are two major things. A third is power. Guitar amp circuits will often be designed to maximize power. This is another thing that makes "distortion" attractive as it is inevitably what you get when you push for more brute power.

Not only is the tube circuit somewhat dfferent but the driver/speaker is too. There is always some trade-off between frequency response, efficiency, and power handling. Audio speakers tends to sacrifice all for flat response and guitar amp speakers do not opting for max power handling and efficiency.

That being said there are a lot of similarites in the designs too as it does not take much of a design change to introduce a little distortion or increase power a little. However, at least in good guitar amps, it is not a matter of just introducing any old kind of distortion.

Decent answers to your questions above could, and do!, fill a good sized book and require a bit of work on your part too. If you are interested in audio and guitar amp design one of the best sites on the web is guitar amp maker Randall Aiken's site. http://www.aikenamps.com Take a look at the "tech info".

Also look up any of the books by Kevin O Connor especially "Principles of Power" and "The Ultimate Tone"
He is another guitar amp guy who writes really clearly and his books are simplified in a good way and practical.
http://www.londonpower.com/books.htm

The first book, Prin of Power, is a great introductory book to tube amp design and, although I have no interest in making guitar amps (i do enjoy playing acoustic), I read it just because so much carried over to audio.

I remain,

Indeed - distortion can be a good thing in guitar amps and a bad thing in audio amps. Distorion in a guitar amp can come from the preamp stage or the power stage or some combination of both. That said, there are also some very fine guitar amps with lots of headroom and I wonder about the similarities between these amps and the audiophile amp.

I take it no one is buying guitar amps of any type and using them for their audio systems.

Thanks for the info and references - they are very useful.

The Mesa Baron is the hifi amp that's closest in design to a guitar amp (consider the manufacturer!) in my opinion. I can't imagine any pure guitar amp that I know of doing well at hifi, though.