Why people still use tube amps when there are plenty of tubes already used in the making of music

[pinger]

But the glowing tubes are cool right?

 

[sergeauckland]

But the glowing tubes are cool right?

In my case, exactly this. Last year's winter project was to build a pair of GEC 912+ amps (EL84 PPUL), and to repair a pair of Quad II amps both for sheer nostalgia for my youth. I use them in my 'study' system for when I'm at my desk, as they look a lot more 'cool' (an oxymoron for a valve amplifier!) than the anonymous but perfectly adequate Technics amp I was previously using. In winter they help with the heating, in summer I tend not to use them much if at all.

I can't say at the loudness I play at that there's any difference in sound, but they do look nice.

Back in the 1960s, I went from a SS amp back to valves (Mullard 5-10s) as the SS amps were so unreliable, but by 1971, went back to transistors as by then we had fully complementary silicon (2N3055 & 2N2955) which performed a lot better than valves without the cost, weight and bulk of output transformers.

Valves are fun to look at, fun to build with and easier to repair, and remind me of my lost youth.

S

 

[MaxwellsEq]

I sometimes feel there is a throwback to "golden age". Tube amplifiers, reel-to-reel tape and turntables featured heavily.

Test equipment before the 80s was not automated with computer control. Signal generators for testing amplifiers were manual devices with a "sweep" often done by hand. Other tone sources were test tapes and LPs. FFTs, noise vs frequency were simply unavailable.

So the thing about this "golden age" is that a lot was unmeasured.

Now everything can be measured. As an engineer I know a BJT or a tube preamplifier can be built to measure as well as eachother, and when that's done, they sound the same. Tube power amplifiers often do have a "sound", as a consequence of output transformer behaviour, but it can be measured and understood.

 

[Sokel]

Tube preamps can be transparent but can also be boring as they apply the same pattern everywhere,often where is not needed.
Thing is the power amps,to get a meaningful,un-compromised output (even with included "effects" ) they need to be really heavy,large and they need a constant considerable service during time.
Their famous soft-clipping (some of them) can maybe come to rescue in small rooms but in bigger ones they just give up on the meter,you can see a straight line where the peaks are.

 

[fredoamigo]

Tube power amps are not only about the harmonic distortion, but also about the low damping factor that enchanges the bass and reduce the treble, it's also about the random factor that gives an impression of realness to the music, while plugings that give harmonic distortion, don't have that randomness, they follow a agloritme in best case.

Tube preamps are only about hte harmonic distortion and randomness of it, not about the damping factor and have a less profound effect and are easier to emulate with vst's or so.

And yes, it's an effect, one that some like and some don't, and it's an distortion of the signal so less hifi in the classical sense of the word as clean neutral amps. But for me it's about the enjoyment of music, not about perfect graphs, and a good tube amp can help with that in my case. That is why i have one (next to other clean amps).

According to Bob Cordell, the difference between transistor amps and tube amps is their way of clipping which is much more pleasant to listen to for tubes, but which is synonymous with the lack of power for both.


Excerpt from an interview almost 20 years old, still relevant today ..

Without getting into how power is measured, how much power do we really
need?
Much more than we think. Ideally, if you are really serious about high-end audio,
your amplifier should never, ever clip. In reality, amps clip more often than we think,
especially on well-recorded music that has high dynamic range, and especially when
driving speakers with efficiencies in the low to mid 80's. My 250 WPC amplifier will
occasionally wink at me with its clip LEDs (every amp should have them!) when
driving my Morel M3 speakers with well-recorded music at levels that are realistic
but certainly not painful. Remember, the peak-to-average power ratio (crest factor) of
well-recorded music is quite high. The average level is what drives us out of the
room, while it is the peak level that impresses us with effortless dynamics. If a 100
Watt amplifier is adequate for a speaker with 91 dB sensitivity, you need a 400 watt
amplifier for a speaker with only 85 dB sensitivity. Put together inefficient smalldiameter
woofers with adequate baffle step compensation and you have a recipe for a
speaker with small net efficiency, often less than 85 dB.
What is the future of amps?
High-end audio will forever embrace "big-iron" power amplifiers. However, on the
average there will be migration toward more use of IC power amps, like the LM3886,
and the use of Class-D amplifiers. However, it seems unlikely that one will ever make
a Class-D amplifier that can sonically outperform the best-designed Class A-B amps.
The newer, less expensive and more compact amplifier technologies may also help
foster the migration of the power amplifiers into the cabinets of active loudspeakers.
So which is it, tubes or SS?
If you like uncolored sound, go solid state. If you like the coloration that tubes add to
the sound, then go with tubes, recognizing that the coloration will often be a strong
function of what speakers are used. Tubes clip more gracefully than most solid state
amps, but again, if you are serious about high-end audio, your amp should never ever
be clipping, whether it is tube or solid state. Because tube amplifiers tend to be
capable of less power, they will be clipping more often into a given loudspeaker.

 

[MaxwellsEq]

According to Bob Cordell, the difference between transistor amps and tube amps is their way of clipping which is much more pleasant to listen to for tubes, but which is synonymous with the lack of power for both

Towards the end of the section you pasted, he says they clip more gracefully.

This is a bit of a generalisation, since it does depend on the design. If you compare BJT characteristic curves vs tube curves, in general, tubes have less extreme behaviour once you drop out of the "linear" section, but ideally, as Cordell states, it's best not to get near the edges of the slopes for any gain device.

 

[Galliardist]

But the glowing tubes are cool right?

Try touching them when in use. Still cool?

 

[Bob from Florida]

If we eliminate bad tube designs - the type that have audible distortion - and use a suitable speaker - efficient enough with relatively benign impedance curve then they should be "good enough'. From a service perspective - especially a point to point construction tube amp - they are "repair friendly". Compare that type of fixability to a modern surface mount multi-layer circuit board design.

Bad amps are bad amps - tube or solid state.

 

[MattHooper]

Tube power amps are not only about the harmonic distortion, but also about the low damping factor that enchanges the bass and reduce the treble, it's also about the random factor that gives an impression of realness to the music, while plugings that give harmonic distortion, don't have that randomness, they follow a agloritme in best case.

Now everything can be measured. As an engineer I know a BJT or a tube preamplifier can be built to measure as well as eachother, and when that's done, they sound the same. Tube power amplifiers often do have a "sound", as a consequence of output transformer behaviour, but it can be measured and understood.

In a recent speaker review, JA heard a sonic change brought about by substituting an audio research tube amp, for an SS amp:

Q Acoustics 5040 loudspeaker Page 2

BBC Radio 3's Night Tracks program, streamed with Roon, alerted me to Corin, an electronica artist with whom I was completely unfamiliar. After an ambient choral beginning, the title track from her Lux Aeterna (24/44.1 FLAC, UIQ/Qobuz) features a sequence with high-level, low-frequency synth...

www.stereophile.com

"It was time to return the Musical Fidelity amplifier to the distributor, so I replaced it with the Audio Research I/50 integrated amplifier. I used the I/50's 4 ohm output transformer taps, as I was already aware that the 5040 was a current-hungry load. (See the Measurements sidebar.) I played the Jerome Harris track again. The sound was sweeter than it had been with the Musical Fidelity—in fact it was too sweet. I measured the frequency response of one of the speakers while it was driven by the Audio Research and found that the 5040's output in the top octave was attenuated up to 5dB compared with the Nu-Vista 800.2. This was due to the fact that the I/50's output impedance rises to 2.3 ohms in the top octave and the Q Acoustics's impedance in the same region drops to 3 ohms."

 

[MattHooper]

The proposal that tube amp sound is related to "soft clipping" doesn't seem that plausible to me IF some of the sonic reports about tube amps are legit.

In other words: One could just wave away any talk of tube amps having a sound as sighted bias in every case, and then there isn't really anything left to explain.

But if one is taking at least some of the reports seriously, there are purported attributes, like the ones I seem to hear, that don't seem related to soft clipping, like the added thickness of the sound, texture, slight frequency changes. They seem consistent at any volume. If it were just clipping characteristics then it seems to me that this would be intermittent at best, not continuous, and it would mean the tube amp characteristics would disappear and sound identical to SS when you turn the volume lower (so you aren't clipping). But, that doesn't seem to account for the consistency many seem to report. (Not to mention wouldn't seem to explain why I heard sonic differences blind testing my tube preamp against a solid state preamp).

 

[dtaylo1066]

Why do flamingos stand on one leg?

So they can get a leg up on the competition.

There are more fake stick-n-the-ground flamingos on Earth than there are actual living flamingos.

I have stated before I enjoy the sound of a good tube amp and believe it sounds different than SS. So, in the spirit of ASR and looking at empirical/measurable data, I have concluded my ears must like 2nd and 3rd order harmonic distortion. I have no nostalgic or historical ties to tubes. If a certain tube sound can be emulated by DSP, I am fine with that.

 

[Punter]

All this talk about "clipping". Seriously, when's the last time you turned your amp up high enough to drive it into clipping??? From my experience, most systems would be run at an effective 10 to 20 watts for normal listening with 8 ohm speakers. I understand that people running subs on media systems might exceed this routinely but for the man sitting in a comfy chair, listening to a jazz record, he isn't blasting it to clipping levels, far from it.

 

[majingotan]

One audio manufacturer puts it "Live, unamplified music has unmistakable presence and clarity. Yet, at the same time it also sounds relaxed and warm." That captures very well the essential character I tend to hear on live music. Whether or not others here live sources that way; that's how I hear it. So I'm trying to satisfy my own impressions. And I find my tube amplification subtely nudges the sound in that direction. When compared to either solid state amps or preamplification in my system (I also use solid state), the sound gets a little richer, warmer, rounder, thicker with the tube gear. A voice will sound less artificial, more natural and dense and human. And at least my tube amps seem to do a neat trick: they add a bit of "texture" and slight forwardness to the sound that makes instruments pop out of the mix a little more and feel more present, and cymbals can take on a bit more pop out sparkle. And yet at the same time the effect is not added brightess, but actually more "relaxed" and easy on the ears.

Manufacture forgot to include the light show they make that significantly changes your mood of perception of music.

I use a very simple tube circuit consisting of 6SN7 driving a single ended triode strapped KT88 that delivers 1-2 watts maximum to my Susvara and agree with the stated quote above but with the addition of my statement above significantly influencing my listening perception

 

[MattHooper]

All this talk about "clipping". Seriously, when's the last time you turned your amp up high enough to drive it into clipping??? From my experience, most systems would be run at an effective 10 to 20 watts for normal listening with 8 ohm speakers. I understand that people running subs on media systems might exceed this routinely but for the man sitting in a comfy chair, listening to a jazz record, he isn't blasting it to clipping levels, far from it.

On my CJ monoblocks the bias-setting LEDs flash when the amp puts out in excess of 5W. I don't play that loud and virtually never see those lights go on (unless I'm really cranking it sometimes to listen from down the hall.

 

[MattHooper]

Manufacture forgot to include the light show they make that significantly changes your mood of perception of music.

I use a very simple tube circuit consisting of 6SN7 driving a single ended triode strapped KT88 that delivers 1-2 watts maximum to my Susvara and agree with the stated quote above but with the addition of my statement above significantly influencing my listening perception

Nice!

I take advantage of non-audio influences as well. For instance between and behind my stereo speakers is my big projection screen, so I'm staring at that when listening. I have colored lights that I can control, from dark moody blue or purple to undulating colors. I find it can positively affect my perception of the sound.

 

[egellings]

Why do flamingos stand on one leg?

They'd fall into the water if they didn't.

 

[AaronJ]

They'd fall into the water if they didn't.

The answer is “because they feel like it,” same as the answer to the OP’s question.

 

[Robin L]

Same reason some people will put salt or ketchup on their food before tasting it.

 

[pablolie]

Why do these topics keep coming?

A. Provide any remote evidence tubes are pervasive in producing music
B. Provide any remote evidence tubes are in any way pervasive in home audio systems these days

 

[DavidShe]

... the sound gets a little richer, warmer, rounder, thicker with the tube gear. ...

Perhaps the tubes provide some compensation for your listening environment which could be too dry for your taste.