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
After decades of various enjoyable SS amps, the push-pull ultra linear tube amp I used in recent years (Factory modded Jolida 502P) provided tube sweetness and was, at 65 watts per side, plenty loud. Great amp. After watching a Youtube interview with Dennis Had, I got it in my head that I wanted to try one of his amps so when a 12 watt per side recent version "Inspire Fire Bottle" showed up on Ebay at a reasonable price, I bought it. It shouldn't work well with my alleged 91db speakers (albeit helped by 2 REL subs), and hey…it shouldn't sound much better than other well sorted stuff I've owned. However, it absolutely has more resolution and tonal accuracy than any amp I've owned by a wide margin…is it the simple design? Better transformers? Tube rectification? Class A single endedness? It simply makes me want to sit there and listen to stuff endlessly…things I thought sounded so-so (A recent Nora Jones CD seemed dark and badly mixed on my old amp…but sounds great with this amp…go figure) now sound killer…a cool surprise that really lives up to Had's Ebay hype in the often hilarious little rants that he posts when he sells something.
Ditto to Wolf’s opinion of the 12 wpc Inspire . ABSOLUTLY amazing . But what really blew me away was Dennis ! 6 weeks ago , I was playing a new matches pair of Gold Lion KT-77’s ( 150 hrs ). I heard a pop , then another , fairly mild . Shut my stuff down and went to bed . Next morning , I switched the 2 tubes, installed a different driver and rectifier . Turned on my system and just let it sit there with the CD on pause. About ten minutes in , a pop in the other Chanel . So as I watched the amp and contemplated a bad tube , Kaboom ! At about 100 dB. Dove for the switch . No light show , just a trickle of smoke from the chassis . Pulled it apart and I had completely destroyed a couple caps , a resistor with such force that it snapped the terminal strip . I emailed Dennis , HELP ! 30 minutes later my phone rang . He said ship it to me and I’ll fix it for free . I said it’s 18 months old and it was my bad tube . He said , It never happens and I’ll fix it or build you a new one for free . I shipped it to him and it was home , fixed and return shipping for free in two weeks. I begged Dennis to let me pay him . He reluctantly said OK , 100 smackers ! How many times have I met a man like him ? Not enough . All he cares about is the Audiophile enjoying his music . Try his amp . Like I said on his EBay feedback - BEST 12 Watts I’ve ever heard ! Then I went to a lower rectifier and the KT77’s and Heaven . Imagine what top notch Mullards would sound like ! I do have NOS 6550 Tungsols , amongst 5 other pairs of various values . And the tube selection for my pre ! Same results with the single E88CC Tube in the gain stage of the Inspire . Flipping Sweet ! It would sound amazing with a good pair of small speakers and stands , and subs ! 


I have heard a recent new product from a well established company with very innovative approach to class AB amplification in my system for a 30 day trial. Incredible resolution. Super clear, dynamic, great soundstage...etc. but after some time too clinical; almost too perfect to the point where my brain disengages from the sound and I want to walk away. Too "high fi". Could not relax with this sound.This is NOT a direction I want my system to go in. I sent it back.

Benchmark managed to make a Class AB amp sound like a Class D amp. Quite an interesting accomplishment. Suck out the distortion with NFB and suck the life out of the music. There is no free lunch with NFB. 
  • Seanheis1, It seems that you have to be very judicious and careful with the employment of negative feedback (NFB). It can provide uber low THD and very high damping factor (DF) measurements that may impress some. The penalty can be dry, clinical and lifeless sound quality. Tread cautiously as it’s a balancing act for certain. Reminds of how some listeners felt about Halcro audio products. Keep in mind that  what is considered clinical and lifeless to one may be amazingly accurate and transparent to another. Subjectivity rules.
  • Charles
All I know is that whatever you get that has tubes it seems to be a blackhole for money if you want to tube roll
.I did not expect that as I was buying up tubes.
I still want more so now if someone in the family asks what I want for Christmas,Bday or Fathersday I'll say" Tubes ".
Between guitar  amps,The Freya and the Primaluna give me 6sn7,5692,12ax7,12at7,12au7 etc.el84,el34,kt66,kt77,kt88 or kt120.