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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
charles1dad's avatar
charles1dad
10,250 posts
 
Tostadosunidos,
I know of two European companies that use the transistor input and output tube approach.
Nagra 300i, front end uses bipolar transistors and 300b tube.
KR Audio with numerous models MOSFET transistors with a variety of tubes.

According to professional reviews and owner’s word of mouth these products sound superb.
Both companies believe that the sound character is essentially the output tubes diving/interaction with the speaker. They believe that transistor input stage is very quiet, neutral and transparent, thus very little coloration.  

Interesting approach and philosophy as most brands approach is the opposite. Just another example achieving high quality sound via a different route.
Charles 
coppy777
141 posts
 
Agree with much of what has been said here. A bit of twist in the response... equipment quality is more important to the ultimate sound quality in the preamp, whatever you use. Getting the magic sound of tubes is more significant in the power amp. Not to suggest low value in either, just where to put more emphasis. I’ve used Conrad-Johnson gear for years and now run their best preamp with both SS and tube amps. As has been said, each combo has their own sound. I do recommend mono-block amps if possible though.
azbrd
102 posts
 
Since I have Maggie 20.7s that require a very strong powerful amp I prefer SS, at this time its a Bryston 4b3.  Preamp is a Mcintosh C1100 with NOS driver tubes and a Modwright Elyse DAC also with NOS tubes.  This combination produces a very warm, dynamic sound that is amazing.  I have never considered a tube amp, I prefer the power and control of a SS amp.
nugat
38 posts
 
I tested various tube/SS scenarios with my Shiit Freya preamp, SS hypex n-core and Airtight AM201 tube amplifiers and Shiit Yggdrasil DAC. Freya offers three options: passive, FET, tube. For the last position I use 1940's VT231 Tung Sols. Here are my observations for preamp/amp combinations. Since I don't hear  meaningful differences between passive and FET positions of Freya, I'll just use "passive" here.

Passive+AM201-- good "tube" sound combo 
TungSol+AM201-- too much of the good thing. Euphony blurs detail.
Passive+ncore  -- maximum detail and truth
TungSol+ncore -- less detail more euphonic. I use it for jazz with female  vocals. The voices become a bit "sunny and smiley".

In practice I use the last two positions for the convenience of switching Freya only and no need of recabling.
 
meiatflask OP
151 posts
 
As the OP, I have thoroughly enjoyed everyone’s comments.  As I expected as I threw the question out there, quite a bit of the discussion is philosophical, and the views are quite different.  And you cannot avoid some of the very practical issues such as speaker needs and tube life/ cost.  

I have avoided the speaker compatibility issues by using relatively efficient mini monitors that are easy to drive, and have a small room where 30 wpc is more than enough.  I know that many of you don’t have this luxury and so your situation is more complicated. 

so, (and knowing that this will not be my final equipment purchase) I think it’s time to buy another tube preamp (replacing my naim ss) to go into my primaluna tube amp.  Rather than bog this thread down with specifics, I’ll probably start another discussion on the merits of a 2-4k preamp versus dropping 8k and making the preamp the most expensive item in my system.

but, continue discussing preamp versus power amp, as it has been great.

Bill
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