Are tubes really “warm”?


Time and again I read posts that claim/assume that tubes sound “warm.” I have not found this to be the case. Having owned many high quality tube amps and preamps, I find that tube electronics present more natural highs than many ss designs. But warm?? Not in my experience. Can someone explain what it is about the tube sound that many consider “warm?”
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Audio terms like warm are relative. Tubes are in general warm relative to solid state. But you have to watch out, because not only warm but a lot of other terms are used as if they're absolute. They're not. They're relative. You may well be like me and consider your tube gear neutral. But to the average audiophile neutral pretty much means it must be solid state. Which if you ask them pretty much always comes down to them retreating to the sanctuary of measured performance. Which is dumb because there is no oscilloscope, graph or microphone ever made that's calibrated to measure "warm". (They don't measure "neutral", or "transparent" either.) But there you go.
It all depends on the type of tube and it's implementation as you surely know. Warm to me means mid to upper bass emphasis or "dark" An EL34 can sound "warm" Tube sound to me means natural tone and body; two things I really like.
This old adage goes back to when most amps were tube-based and used in systems with limited frequency response. Components like carbon resistors, saggy resistor voltage droppers, and tube rectifiers contributed to this ’tone’ of a rolled off upper treble and woolly bass.
In reality, a good modern tube amp has a certain naturalness which can be attributed to lack of solid state transistor haze caused by switching noise and its associated odd-order harmonic distortion. With modern components, tube amps can sound as cool and neutral as you prefer. Conversely, many solid state amplifiers can  sound warm so it’s not a predictable way to classify the type of sound you’re going to get from a specific type of amplifier. To add complexity to the issue, electronic passive component and tube type, configuration and brand selection can also affect how warm or cool an amplifier sounds. 
Of course if you’re going to play CDs with them it doesn’t really matter since CDs are lacking in warmth and air anyway. You can’t turn a pig’s ear into a silk purse. 🐷 
Not with Audio Research. They make tube gear that sounds like solid state. Never understood this brand. 🙄 Why use tubes in the first place if you aim for a solid state sound ??...
Good post @noromance 

The tube sound for me has always been about the presentation, not the linearity of its FR.  There is a holographic nature and weight to images that can be tough to get right with solid state. For me, if a tube amp sounds 'solid state', it means there is no real soundstage depth or weight to images - a flat sound if you will.  Some tube amps do sound like that, and the opposite is true for solid state amps sounding like tube amps, but it is much rarer to find the latter.
*are tubes warm?*, 
 depends on make of amp/design. in general , no , not muddy (=warm). 
but most ~~certainly~~ not sterile sounding,  that is not clinical as their nemesis, the *other* amp design,
(hint = ss amperage)
yeah i am  #1 basher. of ss design. 
The ss groupies just hate me so...
Summarizing the responses thus far:
Tube fans believe that, relative to ss, tube electronics have naturalness of timber, fullness and air.
Haven’t heard from those who favor ss. I’m guessing that they believe tube “warmth” is a lack of musical dynamics and punch - although I, myself, have not found that to be the case with tubes.
I think we should retire the term “warm” altogether, except to denote preponderance of bass relative to treble, which either tube or ss electronics may exhibit. The stereotypical “Tube sound is warm” seems incorrect.
Usually yes but the degree to which varies widely. 
It depends on the design and the company ARC not to warm CJ warmer etc.
What I really found out in tube amps is you can never get great sound of Strat with solid state amps. The sound won't be warm at all. 
It depends on the amp and the speakers, and the era.

The way to design speakers in the top octaves has varied a lot over a few decades, from a rolloff starting around 7kHz, to flat, to ragged and exaggerated.

There were a number of amps which in the past would sound dead cold to me, old Audio Research, but which now sound more neutral and pleasant.
Not necessarily. I’ve heard certain tube circuits and/or certain tubes that could peel paint. On the flip side, some badly designed/implemented tube amps can have massive roll-off and gobs of THD, and that can be used to perpetuate the stereotype of "warm, rich tube sound", but it doesn’t have to be that way. Certain tube headphone amps and cheap Chinese tube amps can be particularly guilty of either kind of bad tube sound - but is that stuff really a proper "tube amp" or should it be thought of more as a novelty? Really good tube gear should be reasonably neutral with THD at least somewhat under control, and featuring good extension on both ends.

     I’ve always enjoyed the sound that tube preamps and amps impart on the overall sound of a system. It’s my understanding that, when tubes and tube equipment begins to distort, they do so in a manner that results in an excess of even order harmonics being produced and added to the inputted signals. As opposed to when ss circuits and ss equipment begins to distort, they do so in a manner that results in odd order harmonics being produced and added to the inputted signals. 
     In general, humans tend to perceive the added dose of odd order harmonics as strident, bright and unpleasant and the added dose of even order harmonics as sounding pleasant, with added body, tone richness and a sense of added dimension to stereo sound stage illusion images. I’ve always found these qualities pleasurable too, thought the term ’warmth’ referred to all these specific qualities in total and initially thought tubes had to be present in the audio chain somewhere to attain these qualities in my various audio system configurations.
     For many years I used a VTL 2.5 TL tube preamp, with a custom set of four NOS (new old stock) Mullard tubes swapped in to replace the VTL’s stock set of four Russian or Chinese tubes, in combination with a series of high current ss class AB amps from Adcom, McCormack and Aragon to achieve this quality of warmth in my systems.        These combinations of a tubed preamp with a ss amp were all very good; providing adequate power to drive my inefficient pair of Magnepan 2.7QR main speakers, providing good bass along with detailed, smooth but never overly bright midrange and treble performance with just a touch of added warmth.
     However, I have to agree with others on this thread that mentioned there are rarely absolutes in this hobby. I suggest that particular component combinations need to be auditioned prior to claiming any overall system sonic results with any specificity.
     For example, my current system consists of a ss Mark Levinson 326S preamp combined with a pair of high powered class D mono-blocks. My overall system sound is very similar to my former systems using a tube preamp, including the touch of warmth. But I perceive the ss 326S as having additional strengths, such as improved bass performance, a lower noise floor, improved detail, a more neutral presentation and a much improved stereo sound stage illusion ability that is more dynamic and spooky realistic on good recordings.
     I now believe that good body, tone richness and a good sense of dimension to stereo sound stage illusion images are more a function of the qualities of the music, the quality of the recording and the quality of the reproduction system as a whole rather than the inclusion or exclusion of tubes in the audio chain. I believe absolutes in this hobby are best avoided.

Tim
@noble100   

and the quality of the reproduction system as a whole rather than the inclusion or exclusion of tubes in the audio chain.


+1....you said it so I didn't have to. As if all you're listening to is a tube...ha.

Newer VTL, and AR both sound like the older Krell, to me. Nothing warm about it.  Citation II, MC30, Marantz #7 and 9s that's the warm sound of valves people refer to. When folks say it now, I doubt a lot have heard the old valve sound. Like noromance said. Different parts, and a lot tighter tolerances, now.. 50 years ago... They ran WARMER too, oh my...... LOL

Regards
 I believe absolutes in this hobby are best avoided.

@ Nobel100, well sure, in general, ss amps display a  characteritic, which tube fans have no desire to ever go back to. 
Speaking of ARC, I've only heard a  ARC system with a  speaker that may have colored, in fact no doubt did color the sound. 
can't reacll the big tower speakers,, He had  a cary 303 cd player
I did not like the sound. 
As I say, i recently auditioned a  hefty tube pre (retails @ $3K+) , i do not want to call out the brand.  But just did not synergize in my system (lame excuse). Maybe one of the other models has superior sonics, i have no idea, Not willing to chance it.
But I do know fora  fact  there  does <<NOT>> exist any ss pre amp in the universe that would even comke close to meeting my expectations. 
I am not speaking in generalities here,,I am stanch dogmatic religious on that POV.
Now as for amps,, sure there are some tube amps, than  may lose in a  shootout with some ss amps, this is quite likely. 
But in general, a  well designed (that'll cost ya bud) tube amp will out perform  ss amps  costing 2X's+ more
THere is hype in both designs. But in general , you can find more snakeoil flowing through ss designs. 
You can take top 3 ss amp designs in the world, hook em up to highly colored (crappy/high distortion/high fatigure, muddy/murky/not warm, but HOT as hell), and you'll end up with a  pile of _____
Now take 3 top tube designs in the world , with same highly colored speakers,,and you'll at lesat get some semblance of a  live stage experience. 
This is the point i am trying to emphasize.
World's very best ss designs can not match worlds finest tube designs. In all areas of  sonic fq resolution/sound stage/live experience. 
I now believe that good body, tone richness and a good sense of dimension to stereo sound stage illusion images are more a function of the qualities of the music, the quality of the recording and the quality of the reproduction system as a whole rather than the inclusion or exclusion of tubes in the audio chain. I believe absolutes in this hobby are best avoided.

^Amen.
Hello mozartfan,

     Apparently, you seem to have an absolute inclination and preference toward absolute thinking in this audio hobby.  I've learned through personal experience that claims of audio absolutes are of little merit, are rarely reliable and cause the closure of an individual's mind to new ideas, discoveries along with a voluntary forfeiture of the very process of continued learning and growing itself.  Well, good luck with that.

Tim
Note that Kaitty's said his rig is a Sony Discman through Grado SR80s without earpads, so there's that. 
NO! And transistors don't sound cold!
Wolfie knows only what I want him to know. So there’s that.
Is it the tubes, or the circuit design, quality of the transformers... I have owned complete tube systems, as well as mixed systems (tube pre + SS amp)


For more then 15 years my systems have been 100% SS. My current system starts with the: Oppo 105 with power supply and incoming IEC replaced with Furutech Rhodium IEC with attached pure silver tail connecting to the new LPM and the 110/220 switch replaced with a silver jumper. The tray is loaded with New Dark Matter which helped tremendously with the digital nasties. One meter WireWorld series 8 XLRs direct to my Ric Schultz EVS 1200 amp; dual mono IceEdge class D modules with lots of tweaks. The tops have been removed from the 1200 and the 105. No preamp. WireWorld Series 8 speaker cables connect to Emerald Physics KCII open baffle ~ 96db efficient.

Everything, including the speakers, have Machina Dynamica springs under them


I only spin cds. Some sound dry and brittle (indeed on greatest hits discs some songs sound dry and brittle while others sound terrific), whether they are red book, DVD-A or SACD

hth
I always thought the warm sound associated with tubes came from distortion and HF roll off. 
I always thought the warm sound associated with tubes came from distortion and HF roll off.
The 2nd and 3rd harmonics are responsible for 'warmth', but tubes can have plenty of bandwidth- the old Harmon Kardon Citation 2 had bandwidth to 100KHz and that amp hails from 1959. So the HF rolloff thing is a bit of a myth.

Flipping the coin over for a bit, it is also distortion that causes transistor amps to have brightness and harshness. This is the case even though the distortion in question is quite 'low'. But the ear uses the higher ordered harmonics that cause brightness to sense sound pressure, and so is arguably more sensitive to them than anything else! So even though transistor amps look like they have low distortion on paper, the ear itself doesn't think so and can hear that distortion easily.


mozartfan
196 posts05-25-2020 7:33pm

This is the point I am trying to emphasize.
World’s very best ss designs can not match worlds finest tube designs. In all areas of sonic fq resolution/sound stage/live experience.

You’re not emphasizing anything. You’re stating the best power amps, are valve and solid state can’t match valve design.

The top three to boot.

Which 3/3? What are you comparing?

"As I say, I recently auditioned a hefty tube pre (retails @ $3K+) , I do not want to call out the brand. "

If you want a good preamp, 3k might get you there, if you want a GREAT one, you might have to spend a little more than 3K.

I just sent back a little Freya + (1000.00) nice unit. It had a problem. It had 3k sound, not 6-10k sound.. Yes, GREAT sound can cost a lot of money. It doesn’t have to, but it sure can.

"But I do know for a fact there does <<NOT>> exist any ss pre amp in the universe that would even come close to meeting my expectations. "

WOW!!

I’m a Mac guy, I have a SS MX120, that will not only match, but will blow the doors off a LOT of valve preamps. I own a few, mostly Mcintosh, C8s,11,20s,22,2500,MX110s,120s,121,150 (just sold), Krell, Marantz, Cary, VTL, CJ, and two hand made, by me..

I paid 750.00 for it, cracked glass. A pure sonic nugget, especially with planar/ribbon setups.

I picked up a second MX120, the sonics were the same. That MAC unit is one of the best PURE STEREO, pre I ever owned, and it is a 5.1-7.1 surround system. Go figure! 1600.00 for this one.

I've sat a lot of TUBE HEADs in front of that preamp and they KNEW it was all valves, powering the system.
LOL it was all SS. Mac and Pass Lab.. They knew me, right... It had to be valves.. I know I can fool a lot of folks with that set up.. You aught to hear it with a valve power amp, like Cary, or Mac will work..

A buddy has a new SLP 05, he thinks it can do it..we'll see. I bet it's close.  8,000.00 + (he won't say what he spent) - 750.00 LOL with a cracked glass..

Come to find out it is a Stereo front end, with an additional processor.
Not a processor that will do Stereo, but both are onboard.

Listen to the 50 series of Mac.. C50-53? If you had, you wouldn’t make statements like that.

The C45 uses the same front end as 120,150, (there are a few that used it)
I guess that why it is so coveted in the Mac community.

You like valve preamps, (I think), but "know" a SS "does not exist" that would meet your needs.

I found a few that work great for me..

Or save a lot of money and get a great integrated. If I were starting out again, I would sure think about it..

Regards


I just read it.. Geezzzzz I still have most of the stuff they were showing, shy the MC2300 Mac. I sold mine 20 years ago.. "The Fisher" killer pres
Kits were great too.

Hello mozartfan,

     Apparently, you seem to have an absolute inclination and preference toward absolute thinking in this audio hobby. I've learned through personal experience that claims of audio absolutes are of little merit, are rarely reliable and cause the closure of an individual's mind to new ideas, discoveries along with a voluntary forfeiture of the very process of continued learning and growing itself. Well, good luck with that.

Tim



well i've been in and out hifi past 40 yrs,,so i have some limited experience,
I do research,, lost out on a  few decisions,,now i havea  tech guy for consultation, and suggest everyone should havea  tech geek for references on any decision. 
But yeah, as far as ss technology , not for me, My mind is closed..I'll take tubes for all its <<good and bad>> 


Tubes to SS are sort of like analog to digital. Many think this has to do with even order harmonic distortion. I do not say warm. I would say ambient is more like it. Tubes and analog seem to be more ambient. This is euphoric and not necessarily accurate, a very old argument. Like Nelson Pass says, "audiophiles just want to be happy." I say audiophiles just want to torture themselves. 
When I run my tube integrated, my whole room gets "warm"
When I run my tube integrated, my whole room gets "warm"
Post removed 
This is always fun.  A coworker stops buy, walks in the front door sees tube stuff. We listen to a few songs, he says he enjoyed the listen, and never realised tubes could sound so, so wonderful.. I never said a word... It's ALL SS.  Another time, visa versa. I get told how SS is so much better, clean, sharp, dynamic, bass is right there... We're listening to all Valves.. Might be 50-60 year old tec too.. I never say a word..
Same guy, would NEVER go for a class d.. or tubes.. C20, Nord NC500
He knew it was my Krell/Krell set up...Just knew it...
LOL...Hay when it's right it's right.. Who cares... I'm stuck on better, for a reasonable $$$$$ amount.

Regards
Tubes and analog seem to be more ambient. This is euphoric and not necessarily accurate, a very old argument.
This is all about that first watt, where low level detail resides. Its not about euphonic character, just more accurate- and since there is more low level detail, more ambience as well.
Does organic and natural=warmth. SET tubes are my long time preference. I have difficulty describing the sound of my rig. I just know I like the “warm sound” of my SET amp and preamp and my lovely TT. Speaking of “warm”, After many years of listening to my CD transport and my tube DAC, I am now addicted to vinyl. When comparing vinyl to digital, my vinyl sounds “warm”! I guess the proverbial “warm” is more to my subjective liking. SS sound is subjectively more “cold” whether tube or solid state.
Kaitty apparently wanted everybody to know about his Walkman/Grado rig as he's mentioned it here more than once, which he may backtrack from any second as hey, so would anybody else.
I went pro, Wolfman. Just like you. 🙄