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
I've found that the "expense" of tube power amps based on tube replacement cost is assuaged by the fact (a fact to me anyway…which is as "facty" as I need) that often the tube amp is cheaper to buy relative to the sound quality of SS amps. Case in point: I compared some expensive SS amps here and there over the years to my faithful all tube (except the rectifier) Jolida 502P power amp and the Jolida, with nice sounding tubes, sounded simply better in every case, and was inexpensive…and now I own the best sounding amp I've ever heard, a Dennis Had "Inspire" SEP, which does require relatively efficient speakers but costs around 1200 (mine was slightly used) to 1500 bucks…an SS amp with this much mojo would be more money it seems. First Watt? 3 grand if you're lucky. And the Had amp has exactly 4 tubes. You don't like heat? I get that (sort of), but have never been bothered by tube heat unless I just burnt my fingers biasing or dusting or something…my mansion has AC anyway, and I can get my valet to dust if he hasn't been drinking.
Unless, of course, you need the power and control a high power SS amp can provide. Then a tube pre is the best bet. High power tube amps tend to be big, heavy, expensive and hot, not to mention they go through tubes much faster than a tube pre..

I'd personally love a small, near field listening tube rig with some sensitive speakers. But right now I love the power and control my tube pre/class D setup brings to the table.. I'd miss that if I switched.
Hmm. What is "tube" sound?
Smoother and more detailed than transistor, more lower ordered harmonics which are harder for the ear to detect. Less higher orders that the ear easily detects as harshness.

************************

If you really really have to make a choice of which way to go, my money is on the tube preamp.

The reason is simple: I don't care how good your amp or speakers are, if the preamp looses definition, there is nothing you can do to replace it downstream. Tubes simply make more detail than transistors (and also without brightness); they are easier to listen to for hours too, so send that to your amplifier.

The problem here of course is if the amp isn't up to the task, you won't hear what the front end of the system is doing. I do regard the use of a tube preamp with solid state as a compromise.

If you really want to hear all that is on that LP or CD, get a tube amp to go with the tube preamp.

Some people think that they don't want the tube amp because of reliability or heat concerns. Tubes are easy to deal with (they are in sockets after all) and heat is a function more of what class of operation the amp employs rather than whether or not it has filaments. A solid state amp biased to the same level of class A operation will make 90% of the heat that a tube amp does. IOW, many tube amps run hotter because they are biased harder.

Transistor amps tend to be biased at very low currents; that's the main reason they make less heat. 
Ralph you of course make a compelling case for tube preamp and tube amplifier (which is my chosen route). The OP is asking which component would yield more of the tube character or effect on the audio system. 

Your argument for the tube preamp advantages I surely understand.  However in the context proposed by the OP I would go SS Pre/tube amplifier rather than tube preamp/SS amplifier.  Obviously as this interesting thread has demonstrated preferences are all over the proverbial map. This is as expected in this subjective realm. 
Charles 
Charlesldad and atmasphere among others provide good advice.  My advice comes from a more pragmatic (and perhaps devious) point of view.  Start with a tube pre-amp.  The tubes are typically longer lasting and less expensive, for the most part. Once the mysteries of valves dissipate and their joys become obvious, then one will naturally migrate to a tube amp.  Assuming of course, that your speakers are a good match for tubes.  And then you'll never look back...Bwwahahaha!!!!!
Hi swampwalker, 
Pragmatism is good 😊. If advising someone new to tubes your advice is undoubtedly sound. But if this person asked which impacts the system "more" then tube amplifier.  Swampwalker what's been the case in your own experience?
Thanks,
Charles 
You heard the respected amp designer, so stop talking nonsense. There is no rationale to use transistor preamp with tube power amp.
 

Inna 11-13-2017
...so stop talking nonsense.
Inna, I'll follow up on my earlier response to your contention by speaking with uncharacteristic bluntness. In my opinion, your contention is nonsense.

Regards,
-- Al
 
Inna, I'll follow up on my earlier response to your contention by speaking with uncharacteristic bluntness. In my opinion, your contention is nonsense.
+1
I have had the pleasure to own a fine intergrated SS unit which ran well by itself for many years.  I then paired it with a tube pre-amp and a new dimension of appreciation began.  Then I ran a tube pre-amp along with tube amp.  Then tube pre-amp bi-amped with both tube and SS amp.  My take away from all of this, to answer your question, is the pre-amp had the largest impact on my overall listening pleasure.
Inna, Yes Ralph is a respected tube equipment manufacturer and yes he offers an informed opinion ( something you’ve yet to demonstrate). He is not however an absolute or infallible source. There are other manufacturers of equal status who would provide different opinions, this seems blatantly evident. Nothing is etched in stone, certainly not matters of audio and sound. Inna you’ve yet to give a coherent answer.

Al your bluntness is understood and appropriate, +2.
Charles
For me, in my system, it is tube pre into SS amp.  However, upon listening to a friend's Martin Logan speakers with a SS pre and top notch Audio Research all tube amp, I realized that the other way around can be just as rewarding in the right set-up.  Until hearing that I didn't think electrostatics could get past the somewhat plasticy sound of the mylar diaphragm.  Didn't hear any of that with that tube amp. There was a harmonic completeness that my previous experiences with 'stats had never yielded. Beautiful music and a new healthy appreciation for the musical capabilities of electrostatic speakers.

dpac996, you start your post with asking what is a "tube" sound and end it by making the statement "If you are after "tube sound" cut to the chase; buy a tube amp and relax!" Makes a little sense.

People buy what sounds good to their ears. Tube sound or SS sound are just labels.


"The other way around can be just as rewarding"
Hifiman5 thanks for sharing this personal revelation. Different types of components can be combined with success. 
Charles 
Also it’s another fact (!) that tubes are more fun…you can swap ’em out, hold them and look at them, collect them, watch and listen to them die (macabre, but part of the tube deal), bewilder friends. People ranging from my age group to my kid’s friends (mid 20’s) often have no idea what tubes are, which means I get to have fun trying to explain the damn things (guaranteed to bore the crap outta anybody). Interestingly, once explained to "normal" people, they still don’t care. At friend’s houses they’re often just yelling at Alexa to play something from a 1" speaker. I actually took a foam block and stuck some of my spare tubes in it just to look at them (that's called Art)…fun...stick a bunch of transistors in something so you can look at them…not so much fun. You can use a SS amp anywhere, preamp or amp, and although it may sound fabulous, I KNOW I’m having more fun. I rest my case.
Either combination can give you a great dose of "tube sound". Of course power tubes need more maintenance, and the NOS flavors of large power tubes quickly approach $$$$/unobtanium territory. BUT there are really excellent Russian power tubes made today (KT120, KT150), and tube amps will often have at least a few crucial small-signal tube slots for you to get your NOS on.

On the preamp side, higher gain tube preamps are more likely to cause noise issues your system (i.e. tube rush and/or microphonics excited during playback) than SS preamps or tube power amps. That bears consideration. Also, with a tube preamp feeding into a SS power amp it’s a bit more common to experience an impedance mismatch (i.e. high output impedance into a low input impedance, which throws away gain and caused significant FR aberrations), than with SS pre into tube power. Research potential pairings before proceeding, just as you have to research any power amp’s ability to drive your speakers.
What do you mean by "tube sound?"  I think tube preamps are great because small signal tubes don't "age" much, so they're sound does not change.  I think, done right, tube preamps provide a greater sense of "articulation" or "naturalness" (i.e. absence of glare) to the sound . . . and I'm not talking 12ax7 tube euphony.  Tube power amps, with output transformers, inevitably interact with the speaker in ways that are not entirely predictable, changing the speaker's frequency response.  The combination could be synergistic, or not . . .  And, it's hard to get accurate bass from a tube amp, unless you're driving a fairly high efficiency loudspeaker.   
In any event, tube power amps that generate much over 75 watts per channel have lots of tubes, generate lots of heat and suck down lots of power.  And, in my experience, even in a simple amp like a Dyna Stereo 70, the sound quality changes as the output tubes age.  More elaborate and quality amps (Audio Research) have been known to self destruct in expensive ways when an output tube fails.

Obviously, there are, at a price, tube power amps that do all things very well, but these tend to be both high maintenance and seriously expensive in the first instance.
On the lower end of a budget setup[still expensive to me lol]I have the Freya going into Emotiva XPA100’s and you can hear a difference between the "Hat Trick" of outputs.The tube output also imparts some gain increase.Where it really sounds good tho is the tube out of the Freya into the Primaluna Prologue 5 [has KT88’s in it now].So i would say the AMP makes the most difference for the Toobiness.
Wolf,
I also love the Tube Amp guitar heads and combos.My current fave is a DR Z RT 66 into a DR Z 1x12 Convertible cab loaded with a Scumback Speaker.I do not play out,just at home for fun,and I grab up low wattage Tube Amps when I can.BlackStar,BlackHearts[in the 1,5 and 15 watt sizes],Egnators[Rebel & Tweaker],Jet City,Epiphone,VHT Special 6 and a few others.Heck,they don’t take up much space.I actually have 3 of the Blackheart 1 watt ’Killer Ants’ with 2 of them having the Mojo Mod..ie Tone Control and Line Out.Solid State wise I recently picked up a Orange Micro Terror thats kinda neat
I had an early-ish Egnator for a while and it was really interesting in that you could pan between the 6v6s and EL84s…cool. I don't necessarily collect guitar amps but have owned, borrowed, and played through a lot of different tube amps over decades and have pretty much enjoyed 'em all. I started in the 60s with my cousins white Bandmaster (a friggin' great amp that I eventually owned) and a Magnatone which I didn't initially appreciate enough, and later used early 70s Twins with JBLs that were heavy and loud although the addition of the master volume knob made them work for me. Tubuler.
I like the Mojo around the Tube Amps and Heads.I have an old 1964 or 65 Kalamazoo Model 1 that sounds really kool for  harp and I bought a Green Bullet mic last year to mess around with.
The amps I got rid of to finance my foray into better Stereo and HT stuff were pretty kool.
Marshall JCM600 & 4X10 Cab Half Stack,
Mesa Boogie 50 Cal Plus Combo and an
 Ampeg Jet2 Reissue Combo that was the personal Amp of the Owner of St Louis Music.
I have flipped a few Amps and Guitars in the last several Years.Heck,I mostly play acoustic.I am more of a Bonfire Troubadour..a 'G','C' & 'D' Blackbelt
For $9500 list you can buy a pair of Carver 350 watt amps with a 10 year warranty and Bob claims the tubes will last 50 years:
http://www.bobcarvercorp.com/350wattsamps

" The DC restorer circuit, an exclusive to Bob Carver designs, keeps the output tubes running cool, prolonging their life to beyond 50 years! Prior to the advent of this feature in Bob’s amplifiers, other amplifiers operated their vacuum tubes at a very high idle power in order to keep the distortion low, frequency response extended, as well as for a host of other reasons, related to amplifier performance. And they still do. The downside of doing so is that the tube life is drastically shortened, about three to six years at the most. Worse yet, tube performance begins to deteriorate as soon as the amp is turned on, gradually (and insidiously) robbing the listener of sonic pleasure. In addition to extended tube life, thanks to this invention, there is also no need to purchase expensive matched tubes for the Raven 350."

Now I know there are Bob Carver haters out there, but let’s try to keep to the facts. From those who should know, are these claims realistic?
I think if a tube is on, it's wearing out…I'd like to see what at atmasphere says about this.
If a tube is glowing my understanding is it is wearing out.
Yes, it is wearing out in the same manner that car engine is wearing out when left to idle.
If the Tube is driving a signal then the Tube will wear more compared to it glowing with the just the heater filament being lit up while waiting for the signal.
.The powering on and off does cause some stress to the tube from the Hot/Cold part of that process.I know people with Guitar amps that have NEVER changed a Tube yet..after years of use.
Regarding the statement by Mr. Carver about the 50+ year longevity of the power tubes in his amplifier, I would point out that in general there are statistical approaches that are commonly used in deriving published MTBF (mean time between failure) specifications which produce misleading results.

For example, many of the mechanical (non-SSD) hard drives used in computers have published MTBFs of 1,000,000 hours.  Or in the case of some Western Digital Gold Drives I recently purchased, 2,000,000 hours.  2,000,000 hours corresponds to 228 years of continuous operation.  Does that mean these drives can be expected to last anywhere close to that amount of time?  Of course not.  What it means (and I'm choosing the following figures for purposes of illustration) is that if say 100 drives are operated simultaneously one of them can be expected to fail after slightly more than 2 years.

Similarly, **if** Mr. Carver's 50 year figure is based on similar statistical methodology, and given that there are 12 power tubes in a stereo pair of these amplifiers, it would mean that one tube can expected to fail after a bit more than 4 years.

On the other hand, though, if we assume an average of say 1 hour of use of Mr. Carver's amplifier per day his 50 year figure would correspond to 18,250 hours.  I suppose that if the tubes are driven very lightly, and his design includes good soft start provisions, numbers approaching that figure might not be totally unreasonable.  For example, I recall reading that the Western Electric version of the 300B power tube, when used under recommended conditions, can last for 40,000 hours.  (I'm not sure, though, if that applies to the original 1930s version, or to the relatively recent reissue, or to both).

In any event, personally I would consider Mr. Carver's claim as simply indicating that the KT120 and KT150 tubes that are offered with the amplifier will last considerably longer than in most other applications.

Regards,
-- Al
 
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.
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.
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.
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 .
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 :)
There are some good hybrid integrated amps out there.  Does anyone know of any that are SS pre- and tube power?  I've only seen tube pre- and SS power...
I also agree with ( keithr )  that tube amps provide more of the magic of tubes used with a solid state preamp, but if you want even more magic use a tube amp with a tube preamp of course.
I listen to a lot of red book quality streaming so I went with a tube pre, a DAC that had reviewed characteristics of "warm" and a modern class D implementation Amp.  I am pretty happy so far.  
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 
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.
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.
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.
 
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
All very good comments above.  It comes down to what tube sound you are looking for IMO.  To me building components my DHT DAC provided more of the tone, dimensionality, soundstage, micro to macro dynamic swings then either my DHT preamp or tube power amp.  So my experience may be quite different than others.  My DAC was recently purchased by another Agon member and he has a Dude tube preamp, with NuForce mono block amplifiers.  His Dude provided beautiful tube sound in his system with a SS DAC.  Inserting a DHT DAC added space, dimension, tonality, micro to macro dynamic swings, more separation of vocals and instruments, depth, etc. to the sound.  DHT is a different type of tube sound that is not lush like the old CJ gear.  Different tubes provide different sound to the system, 6922/6DJ8, EL34, 300B, 6SN7, 101D, etc.  To me DHT is more like SS meets tubes type of sound.  Which is the best bang for the buck is another evaluation.  I recently modified a CJ MV-50 power amp.  These amps can be purchased used for not too much money.  It had some damage so I rewired the amp to all point-to-point wirings and added a few upgrades to caps and resistors.  The amp in stock for IMO is a basic good tube amp.  After the upgrade it was a wonderful sounding tube amp.  So in general which is the best bang for the buck, that comes down to the design and your ears.  I cannot say one does more than the other IMO.  I hope this was somewhat helpful.


If it were me I would go for a good tube amp. One that is not fat sounding. That can also be caused by the tube amp / speaker combo. so make sure that the work well with each other. 

So now that you are there you can try some different preamplifiers, both tube and solid state and find out which one you prefer. 
I have been chastised for not indicating that I am a dealer and I just forgot to do that. Sorry. 
Many meaningful contributions presented.  In my experience I have discovered that finding a great preamplifier a daunting task. Let's face it, if your preamplifier can't resolve the micro-details/dynamics along with the other obvious positive qualities, you have already lost the battle. The power amplifier can't compensate for lost or inaccurate information. Seems easy enough but in reality not so much. 
In this light I would place the preamplifier as the most influential electronic component in the audio chain (limited to preamplifier & amplifier).
Remember that our passion and pursuit of our individual goals is not assisted with implemented standards by manufacturer's that helps us along our journey. 
No standard voltage requirements to drive an amplifier to full rated output and impedance issues as well. Many preamplifiers are fussy about length of Interconnects, etc.
Best of luck and happy listening!
I have tried all combination's with exception (by choice) to having both the pre and amp being tubed.

I find for low level, late night listening, a tube amp or integrated amp will sound much better than anything else for the money.

A tube preamp is useful for injecting just enough 2nd harmonic distortion to help ameliorate much of the phase issues or crossover distortion with lesser quality SS amps or Class D amps.

I found that listening DAC direct (balanced) to my class D monoblocks to be pretty much unlistenable.. grey and clinical with an over-emphasis on detail and HF transient response. However i've heard worse for much more $ at trade shows, unbelieveably.

Because of my speakers (86-89db depending on reviewer), I use a NOS VT-99 preamp with class D monoblocks. This gives a very listenable sound with a relatively low noise-floor, and i can crank it up if need be and the soundstage stays coherent and fleshed out.

I also have an older but still excellent Pass Aleph amp which may not have the detail of class D with a tube pre, but driven directly from my DAC, it (despite being only 30 watts) has a very full bodied and spatially delineated sound. It sounds organic enough, or 'real' perhaps, even more so than tube pre to Class D. This is true for most my music except for for tracks with samples of rainfall, where the individual rain drops are slightly smeared compared to Class D with my tube pre. I assume this is most likely due to the Aleph being an old amp, older technology, running in Class A, but more importantly for me, it still doubles down into 4ohms. Maybe a Pass 30.8 would be an upgrade to the old Aleph.

The tube Pre paired with the class A Aleph, sounded too soft and sinewy for my tastes. Direct from DAC was more 'right.'

I use the tube pre and class D for summer listening, and the DAC direct to Pass for winter.

One other consideration is it took me quite a lot of trial and error to find the right tubes for my pre. Maybe $3,000 invested in tubes total, but once i found the right ones i loaded up because their difference is just that great.
let me let me append all that with the answer to your Q.

The amp will give you the most tube sound. Preamp is merely seasoning (although sometimes the seasoning makes for the best soup).
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.


The OP question (and more) was answered 40 years ago by Bob Carver.
Short story:
https://en.wikipedia.org/wiki/Bob_Carver
Long story:
https://www.stereophile.com/content/carver-challenge

In brief, Bob Carver Challenge proved that he could emulate any "top"
amplifier with his 400$ (then) model with some pots and circuits to shape the transfer
function. Therefore it’s logical to employ amps as pure "wire with gain" devices and shape the sound to taste upstream.


   , that’s a Big Question . It feels like I’m trying to arm wrestle an octopus 🐙. So in regards to just your present system . I run a modest price Rogue RP-1, that was a cost driven purchase . This pre uses a pair of 12au7’s . I also have quality interconnects . What I have found rolling tubes in this amp and in regards to your system and musical preferences is this . I can change the entire presentation of the system by changing these two tubes. NOS are my go to BTW. If I run Mullards it’s soft and mild , with the entire soundstage subdued. If I run Amperex Holland , the overall is very bright and forward , losing bass ( not the fish ). If I run Seimens nickel plates the top 1/3 is forward of a fairly full sound . If I run Telefunkens , my porridge is JUST RIGHT . So my opinion is,  if you go tube preamp you can play with tone and the layering of the music ( depth ). This has allowed me to fine tune my system , especially female vocals . If I listen late at night I can enjoy Diane Krall as if it’s live. I also like Natelie Merchant and Amy Winehouse . BTW , my wife put me on Simon and Garfunkel probation . If I was to get a new pre today , I’d consider Don Sachs . Advise from Wolfie and Whitestix is aligned with mine . It’s just that we have similar tastes in music . Everyone that posted has found a good Synergy with what their taste requires. Now that I’m through promoting, recently I blew up my Dennis Had Inspire Amp . While it was off for repairs, I ran a Vintage Marantz SS amp . I had a ton of hiss . Tube pre with too much gain coupled to a SS amp that requires low signal into a 98db speaker equals MUCHO HISS . It’s all about compatibility ! Back in 1975 ( I’m old too ), I ran a SS pre into Dynaco MkIII’s to Jbl’s . It was fun . As far as el34’s , they’re great ! I really like the new Gold Lion KT-77’s and the SED Winged C’s in EL34 and 6L6LGC . As far as the Schiit pre , I love their stuff , but it’s a compromise and you’d be better served going full tilt on a pre . BTW , I’m saving my penny’s for a Gumby or a Yiggy , I have an Uber Bifrost . Good luck on your endeavor, it’s only money and sanity .
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.