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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

Showing 1 response by lou_setriodes

lou_setriodes's avatar
lou_setriodes
698 posts
 
Test Pilot is the only comment above, IMHO, that begins to answer the question.  And to me that is:

What kind of tubes are you talking about and what kind of tube amp design are we talking about?  There are so many variables here.  

The classic tube gear of the 50s and 60s was very tubey and euphonic sounding.  Not the most neutral but that even order distortion was so sweet and lush sounding.  The epitome of tube sounding.

Single ended tube gear in general is a lot less sweet sounding than a push pull design but there's just something so right about the sound.

And PP triode, as written by the late Harvey Rosenberg in Listener magazine, using 4 pin true triode tubes (45s, 2A3's, 300B's, 10's, 211's, 845's, etc) in PP was according to him even better sounding than single ended triode.

I once owned a moded organ amp that used 6BG6's in PP triode and it was one of the finest and lushest sounding tube amps I ever owned and I've had lots of different tube and SS combinations.  Although I couldn't A/B the two amps, my recollection of it was that it was on par, if not superior, to my old McIntosh MC225 amp, which was described in TAS as the best sounding Mac stereo amp, althought the MC240 and MC275 got all the accolades.  The MC225 was Mac's only stereo amp run in triode.

With SS amps, I think mosfet amps sound tubier than bipolar transistors and the chip amps also work extremely well with a tube preamp.

Although its been several years since I heard an EL34 amp, I remember that as being a very lush sounding tube as opposed to an EL84 which was more neutral sounding in the amps that I owned.  

So in conclusion, lots of variables here but if I had to choose between the amp and preamp as which one contributed to the overall tubey sound, I would say the power amp.


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