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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
11,841 posts
 
I think if a tube is on, it's wearing out…I'd like to see what at atmasphere says about this.
If it has B+ on it, then that is the case, slower if there is no B+ (filaments degrade over time as well).

Al's comments reflect the actual reliability, but in this case a KT120 is in use and in practice they don't seem to hold up as well as the KT88. I suspect that the tubes in this amp will hold up only slightly longer than in an amplifier where the tubes are biased a bit hotter, assuming the tubes don't have a defect which can shorten their life, which many modern tubes do.
wolf_garcia
6,708 posts
 
I own a Single Ended amp with 2 power tubes and a single input tube running in Class A (also with a tube rectifier) putting out around 12 watts per side, and have no idea what sort of tube life I should expect. No specs are available from the manufacturer (Dennis Had working away in his lair apparently hand wiring these things himself…maybe with a helper) which is fine with me as the amp is so good, but I still wonder. I run the thing at least 8 hours or so a day…every day…even holidays, unless I'm not at home.
mg16's avatar
mg16
118 posts
 
As the old adage goes: Garbage in, garbage out. I have found the preamplifier to have more influence on the sound than the power amp. A warm, dimensional, tube preamp, feeding a good solid state amp, works for me.
kqvkq9's avatar
kqvkq9
120 posts
 
I'm currently using a transistor preamp and a tube amp. Generally, that's my preference. I've built well over 300 hand crafted tube amps and to me, the amp makes more of a difference. There are no absolutes, such as "It's better this way than that" as I see here. I have no issues telling great differences between amps using the SS preamp that I settled on. I can very much hear all the things I want to hear using a tube amp that way. JGH used to say that the two most important interfaces were amp/speaker and cartridge/tonearm. That was some time ago but that doesn't mean a lot has changed .
kdemangelaere's avatar
kdemangelaere
7 posts
 
I picked up a custom made 'Erhard Audio" tube pre-amp.  (formerly 'tube nirvana').  I dont think I will ever change from it.  They will make it exactly to your specifications.  The sound is PURE and it makes such a difference.  I am one of the believers that you need the front (pre-amp) to be able to show your amp how to play it :)
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