Describe ube sound vs solid state

The difference really seems to come down to distortion. Tubes make more harmonic distortion, but it tends to be of the lower orders (2nd, 3rd and 4th). These are considered musical by the human ear/brain system.

Transistors in general make less distortion, but what they make tends to be of the higher ordered harmonics (5th and up). These are considered amusical by the human ear/brain system.

The brain uses the higher ordered harmonics as loudness cues, so if they are distorted you will get two results: the sound pressure will seem louder (and IMO/IME a stereo should not sound loud even if it is) and it will sound brighter, due to the human ear's extreme sensitivity to these harmonics.

The ear/brain system translates all distortions into tonality. So it converts the distortions of tubes into things that audiophiles describe as 'warmth', 'lushness', etc.

Otherwise both amps might measure flat on the bench, but the ear has a tipping point and will often favor tonality generated by distortion over actual frequency response errors.

There are ways to design tube amps to not make so much of the lower ordered harmonics without creating more of the higher harmonics (fully differential and balanced is one way). There are also ways to design transistor amps to make less of the higher ordered harmonics, and ways to make them make more of the lower ordered harmonics (single-ended, such as some of the Nelson Pass 'First Watt' amplifiers).

Once you understand that its all about how the amps distort (and I don't mean clip or overload, rather at normal listening levels) then you are a long ways closer to understanding what the differences are between them.

One other important difference is how the two technologies overload. Tube amplifiers overload gently and resist making higher ordered harmonics until really pressed hard. Transistor amps make lots of higher ordered harmonics as soon as they are clipped- and so its usually a bad idea to overload them as the clipping is amusical and irritating.

This is why you can often get by with less power with a tube amp than with solid state. It is also why guitar players tend to prefer tube amplifiers, as they often overload the amplifier as part of their 'sound'. Some of the best-sounding transistor-based guitar amps (Sunn comes to mind) were built in such a way that they made a fair amount of lower ordered harmonics- which is why they have a certain following as they are 'richer'.

Since transistor power is considerably cheaper than tube power, to get around the clipping problem a solid state amp will have a lot more power. The clipping problem must be dealt with as music tends to have powerful transients which makes it difficult to reproduce without distortion.

I just put two Gold Lion 12AX7's (reissue) in my modest Vac Avatar and spent the weekend basking in the sound they brought to album after album, revealing new attributes and making the performance glow with life. A $70 exercise, in the direct signal path, that is not possible with SS. I had been considering a big Mc452, but I now think something would be lost regardless of how good that is. Maybe because it would just sit there with no interaction except off/on.

The only Pass I've heard at home was the Aleph0 and matching Pre. I found it boring, but could easily have been a speaker mismatch. Then they exited my price range.

The best thing about Pass amps is the meter, and I've found they sound fine mostly...I like the "first watt" philosophy as really the tonal qualities are all that matter and it's up to you to decide how much horsepower you need. Pass is one of those companies that says something like "sounds close to tubes" often and makes me even more of a tube head...I also recently installed a pair of Gold Lion 12Ax7s in my amp and they're great, along with KT150s to add a "hot pickle" vibe. Fun...

tubes are dynamic & make listening like an event whereas SS to me is like a reproduction which can be very good like Pass, of which I've owned a couple pieces. Thanks to my great guitar playing, record store owning buddy who swayed me towards tubes years ago (RIP Charlie).

Now that's interesting Pehare. I would have said that SS is dynamic. But, I'm remembering listing to the top of the line Wilson speakers, driving by an AR REF250 and a AR REF5SE and I have to tell you, I really stopped trying to determine the "sound" and was smiling all through the experience. Whenever I visit my favorite store in San Diego (Stereo Design) I always go in and listen to this system with my music and just smile. I forgot the SS vs Tube debates and just enjoyed.

I remember years ago (many, many years ago), when I was going to upgrade speakers to the then new Martin Logan Sequel IIs. at Robertson Audio in Los Angeles. They were setting up the room and while waiting, we took the opportunity to listen to the Top of the Line $35,000 turntable, Goldmond (spelling?) top $75,000 speakers driven by Mark Levinson 23.5 amps and that was the only real time other than the AR250 experience that I couldn't stop smiling. Wow!!

When the artist steps out of the speakers and the sound stage magically appears in front of you and you are "there", the smiles just don't end. I promised myself that when I could afford those 23.5 amps, I would get them. I made the same promise with the AR REF250 amps.

I don't care if it is tube or solid state. If the sound makes me remember and smile like that again, I'm there.

Of course, I do have to be able to afford them. sign.....

enjoy