If I'm looking for "Tube Sound", why would I put a Tube Pre in front of a SS amp?

I recall reading a number of articles on the Internet that indicate that while audiophile grade equipment seeks to avoid the distortion you are speaking of, other audio equipment such as some guitar amps seek to embrace it. So for the lay person like myself, while what you have indicated is very likely if not completely true in most cases, it seems conceivable that it may not be true in all cases. Meaning, while most people may perceive those higher end harmonics as irritating, I'd venture to say there are those that welcome it to some degree or another.  

What you read on the internet about guitar distortion is obviously inaccurate. This might come as a surprise, but its the guitar industry, not the hifi industry, which is why tubes are still in production after all these years. The reason for this is simple enough: when you overdrive a tube amplifier, it rounds the the waveform rather than chops it off. If you have a grounding in physics, you know that the corners of the chopped off waveform are higher ordered odd harmonics which are very irritating to the human ear. Guitarists prefer the rounded waveforms of an overdriven amplifier as part of their 'sound' about which they are quite picky!! I play in a band FWIW and am involved in the local music scene and have seen this first hand many times!

As it sits the guitar industry sells many more vacuum tube amplifiers than the hifi industry does- in fact they dwarf the hifi community. So they can dictate to the tube manufacturers what tubes are important. That is why there are EL34s, 6550s, 6L6s, 12AX7s, 12AT7s, 12AU7s and the like- those are all guitar amp tubes.

Now if a guitarist wants more 'bite' or 'crunch' to cut through the mix, often he or she will add a stomp pedal that makes a certain type of distortion. Some of these do indeed make more odd ordered distortion! But as any guitarist knows they have to be used with care to get the sound they are looking for, which is often an emphasis and not how they play all the time.

@mapman This is just me of course but I don't like the ARC preamps for the most part. It does seem like their later ones are better, but you don't have to go back very many years and the earlier ones seem kinda dry (indication of odd ordered content or lack of bass??) to me. My opinion only of course!

@inna  no worries! I agree that Rasmussen is one of the best Euro designers. I regard it as a great pity that Gryphon was the target of a disreputable reviewer here in the US some years back! I was in the Gryphon room CES at the time that the reviewer threatened Rasmussen that if he did not let the reviewer have the amplifier review sample for free he was going to trash it in the upcoming review.  That is exactly what happened some months later; that is part of why I feel that bad reviews are unethical. **That** is a topic for a different thread!!

The reason to put a tube preamp with solid state is if you have to compromise and want the benefit of tubes, a tube preamp will give you smoother sound and more detail than a solid state preamp. There is no way to gloss that problem over downstream; once you've lost that low level detail its gone.

However, if you really want to treat yourself go with tubes all the way. That way you get the additional benefit of reduced higher ordered harmonic distortion, which to the ear sounds like brighter and harsher, and is the thing with which transistor amplifier designers struggle. Its true that those harmonics are minuscule compared to the greater amount of lower ordered harmonics typical of tube amplifiers, but the ear uses the higher ordered harmonics to calculate how loud a sound is and so is far more sensitive to them, in fact more sensitive than test instruments.

FWIW, its not beneficial regardless of a tube or solid state amplifier, to working with a speaker that is 'hard to drive', especially if that hard to drive aspect is low impedance. The simple fact is all amplifiers will make greater distortion if you make them work hard, and the distortion we are talking about is audible as a harsher and brighter top end. You can see this increased distortion in the specs of all amplifiers! IOW if high quality reproduction is your goal you are simply better off avoiding speakers that are hard to drive.

@sbank you might try out a preamp that uses 6SN7s... once you hear what the 6SN7 does its hard to go back to miniature tubes.

But, lets be truthful and real hear. Tube is better than solid state? I don't think so. Nor do I believe that Solid state is better than tube.

What tubes do better than transistors is not make higher ordered harmonic distortions to which the ear is very sensitive and also perceives as irritating.

That's not a matter of opinion its a simple fact and not a matter of debate.

If you don't believe me ask Nelson Pass or John Curl, two of the best solid state designers in the world.

All designers worth their salt realize they won't get rid of distortion. The question then  becomes how to design the amplifier to make the least amount of the most irritating types of distortion. If you read their materials you will find that both of the above designers are very aware of this fact and it is their pragmatic nature that allows them to design some of the best solid state amps made.

Now what solid state does better than tubes is they can drive a wider range of loudspeakers while maintaining flat frequency response (although the latter is often a function of how much negative feedback the amplifier employs).

This is why I was careful to make my points in my prior posts the way I did. I did not say that 'tubes are better'- end of discussion. I pointed out what their strengths are in the context of this thread.  It is true that not everyone will like the facts as stated, but just because we don't like a fact does not change its reality. 

@mapman I've regarded the Class D technology as a sort of rising star. I've yet to hear one that beats a good tube amp in my system but I've not heard them all by any means. I use a class D amp in my keyboard setup in my band and it works pretty well- better than the traditional solid state amp I used before- I get what you say about not having the same artifacts.

However that seems to play to my point which is to use a tube preamp and a solid state (class D) amp rather than the other way around. Is anyone making a class D preamp yet? A quick google search didn't find any examples.

@unsound  Its funny about that- he knew others were in the room. As far as I know he's not been writing for years now.

@inna I don't agree but I am going purely from personal experience. As I said before, its a topic for another thread.

It all depends. Good sound is a team sport that includes not only all the technology playing together but the room and the listener so its always hard to predict outcomes.

Agreed!

@inna , I don't see a video on the Purist site that shows a turntable. I hope you are not taking your evaluations from youtube seriously! From Peter Breuninger, who made the video I found on that site:
"I urge you, If you want your system to sound believable, these guys are some of the first to call."  You can hear him saying that right at the end of the video.

That was at the RMAF sometime in the last two years, in which case the turntable would have been a Kuzma Reference.

@unsound I've got no reason to think that the exchange I saw was not genuine.