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For tube sound, which is more important: preamp or power amp?

I have always loved the “tube sound” - warmth, midrange, soundstage. Through the years (since about 1975), I have owned many tube and solid state amps and preamps, in various combinations. Presently, I have a tube amp and a solid state preamp. But like most of you, I am thinking of making changes, again.  Not to cloud the discussion, the specific brands are not important.  I also listen to acoustic music, females vocals, love mini monitors, EL34s, NOS tubes, and don’t care that much about bass.  So you can see that my taste fits the tube sound very well. But I have had systems that are too warm, not enough dynamics or details, and fat in the low end, too.

okay, now to the discussion.  To produce the tube sound, which is more important: the preamp or the power amp?  Let’s talk in general, and (if possible? May not be) not tied to one specific piece/brand/model of equipment.  I know there are exceptions to any general rule.  Not sure if it makes a difference to your comments, but I have no phono and am running line stage only.

As an attempt to prevent the conversation as going in a big tangent, let’s assume equality of price/quality. i.e. not comparing a $10k power amps contribution to a system to that of a $1k preamp.  Let’s also assume that the amp (tube or solid state) can drive the speakers just fine, such that compatibility does not limit the decision. And ignore mono blocks versus stereo amp differences.  

two follow ons: I have  the perception that preamps give you more bang for the buck - meaning that it takes less money to get a great tube preamp compared to a great tube amp.  Agree/disagree? And second, I have never owned a tube dac or CD player, and will assume that tubes in either of these is less critical than in a preamp or power amp. Agree/disagree?

i am interested in your thoughts.

Bill
meiatflask
atmasphere's avatar
atmasphere
11,849 posts
 
Also, looking the specs of most tube power amps it seems the S/N ratio isn't nearly as good as SS amps. The THD numbers aren't as good either with 1% at full power not uncommon. SS amps' specs look considerably better. Is this typical?
The problem here is that the ear puts a different weighting on what harmonic distortion is present. IOW, it almost does not care about the 2nd harmonic, but cares quite a lot about the 7th and other higher ordered harmonics. So a tube amp tends to have lower orders to which the ear is less sensitive; solid state amps have more of the higher ordered harmonics than tube amps.

The ear translates all distortions into tonality. So the 2nd contributes to 'warmth'; the higher orders contribute to brightness and hardness. Both are colorations!

The bottom line here is that although solid state amps appear to have less distortion, the distortion that they do have is far more audible and objectionable to the human ear. This is why tubes are still around decades on after they were supposedly 'obsolete'.
nickolaspappas
40 posts
 
i 100% with avanti1960. the majority of the tube sound/magic/characteristics comes from amp.
rockadanny
1,226 posts
 
My experience has me agreeing with nickolaspappas.
phastrone
24 posts
 
Interesting that this topic should come up again just now...Here's a copy of a question I logged on to ask...
"I'm using a Rogue Audio Cronus Magnum 2 biwired to Vandersteen model 2cs...I have a chance to pick up a Hafler DH200 cheap. Seeking opinions as to whether biamping with a solid state amp to the low end will be a net loss or gain...I'm guessing that it will tighten up the bass, but I'm worried that it will detract from the signature tube sound of the Cronus. Opinions?"
My best (remembered) sound was a couple of decades ago with an earlier iteration of the Vandersteens, a CJ tube preamp and the DH200 with Musical Concepts mods. (Mid fi...I know) Anyway, I'm going to pick up the Hafler and try it again...I'm not expecting an improvement, but we'll see...I'll post the perceived results on this thread if that's OK...
atmasphere's avatar
atmasphere
11,849 posts
 
Getting the two amps to work together properly will be a bit of a challenge. Unless you use an active crossover, I think you will find that to a very difficult task. The problem with using an active crossover of course it that its not actually tailored to the speaker, and every one that I've heard has imposed its own signature, which is why I try to avoid them unless they are used in a subwoofer.
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