[Tarttett]

I don't think I've seen anyone not describe a tube amplifier as warm. Do tubes necessarily make sound warmer?

 

[MohawkUS]

The answer is perhaps a bit more complicated than you expect because the term 'warm' tends to be heavily loaded(we don't all use it to describe the same traits.) If you are using warm to describe tonal balance the answer is no. Tubes are not always more mid focused.

If you mean it in regard to fullness of sound then maybe. I'm personally not a fan of tubes and I've owned quite a few tube amps with the goal of finding one that I do enjoy. The only trait which has carried across them all is a certain tactility of sound where music takes on a 3D and solid sound. It sounds great worded like that, some refer to it as tube magic, what I hear is a subtle veil subtracting from ultimate crispness & speed with a slight homogenizing effect on music. This effect is lessened on tube amps using NFB and of course different amps will bring different things into the picture(some of them being exclusive to tubes) but this constant remains. I've owned solid-state amps which are similar in fullness but never one with the recording independent depth factor.

 

[Currawong]

To answer @Tarttett, not necessarily. It depends on the design. An amp, either solid state or tube can be designed to "sound" any way the designer wishes. I think one of the attractions of tube designs was the "wide" sound they have. This is, from my understanding, due to the crosstalk properties of some tubes (or maybe it is just the circuit). However in recent times, some manufacturers have set up circuits with deliberate even-order harmonic distortion, which sounds quite pleasant. That, along with other things, can make a sound which seems to be "warm" as some people describe it. But it is absolutely possible to have a tube amp that is not warm at all.

With some variation, I think one of the attractive aspects of tube amps is that, depending how much money you want to spend and what you like, you can fine-tune the sound via tube selection to better match your preferences.

 

[Tarttett]

@MohawkUS Your description sounds like what I would expect my impression would be in hearing a tube amp. I've thought that solid-state would suit me best, but I still need to give tubes a try. I'm curious to see how I'll feel in trying them with a pair of notably bright and detailed headphones particularly.

@Currawong What do you mean by "wide" sound? I would have thought that a widening of the sound would mean more separation, but if there's a "slight homogenizing effect" I guess that means that the sound is "stretched"?

 

[Currawong]

For whatever reason, if you boost the bass and treble slightly, you get the impression of width. I observed that if you measured the crosstalk of some amps, you'd see a V-shape to them, which resulted in that effect. That is maybe what one could say is the classic tube sound. I do think though that many people buy tube amps for a slightly euphonic sound.

 

[MohawkUS]

@MohawkUS Your description sounds like what I would expect my impression would be in hearing a tube amp. I've thought that solid-state would suit me best, but I still need to give tubes a try. I'm curious to see how I'll feel in trying them with a pair of notably bright and detailed headphones particularly.

@Currawong What do you mean by "wide" sound? I would have thought that a widening of the sound would mean more separation, but if there's a "slight homogenizing effect" I guess that means that the sound is "stretched"?

Stretched front to back might be a good descriptor, you could also refer to the tube effect as a halo. Listening to organs, accordions, vocals, or wind instruments I find it easy to picture the air moving as the instruments are being played; it makes these instruments sound much more real and present with you. It doesn't translate so we'll into metal or electronic music where it feels like a slight loss of control over transients.

On bright & detailed headphones one thing I can say is that tubes have a way of lessoning fatigue without reducing the volume of the highs. You won't get razersharp precision so what was a piercing treble before becomes more glossy or sparkly. This is one part of the tube sound I've found can be achieved with transistors or DAC swapping.

 

[Tarttett]

Stretched front to back might be a good descriptor, you could also refer to the tube effect as a halo. Listening to organs, accordions, vocals, or wind instruments I find it easy to picture the air moving as the instruments are being played; it makes these instruments sound much more real and present with you. It doesn't translate so we'll into metal or electronic music where it feels like a slight loss of control over transients.

On bright & detailed headphones one thing I can say is that tubes have a way of lessoning fatigue without reducing the volume of the highs. You won't get razersharp precision so what was a piercing treble before becomes more glossy or sparkly. This is one part of the tube sound I've found can be achieved with transistors or DAC swapping.

I'm eager to try a tube amp now. I have a pair of headphones in mind for each of those descriptions you gave. It sounds like they would be suited pretty well.

Is crosstalk an inherent part of tube amps?

 

[Currawong]

Crosstalk is part of all amps. It's a measure of how much one channel leaks into the other. I wouldn't worry about it -- I was just explaining the technical reason for reason some amps sound they way they do.

 

[Mikem53]

It depends on the amp designer other factors on how “tubey” it sounds.. I had a CJ amp that was overly muddy thick and slow sounding.. tube radios and stereos of yesteryear had similar sounds.. My last tube amp was the BAT VK75SE which was more SS sounding.., fast and detailed.. but still had a SET type sound on vocals and strings that made it stand out above most SS Amps I’ve heard.. but the downside was Class A heat and tubes needing frequent replacement.. BAT runs their tubes hard and they don’t last too long even by tube amp standards..
Tubes were designed For Audio.. not for switching devices.. They have a purity and pleasing sound that usually doesn’t measure well.. but is more musical and less fatiguing than most SS amps

 

[Articnoise]

The answer is no, tubes doesn’t’ necessarily sound warm. Many tube amps has a bit of mid-range emphasis though or sound slightly euphonic, lush or rich compared to neutral sounding SS amps.

 

[Tom-s]

Here's an interview with Dan Schmalle. President for life of the Bottlehead company. He's been in tubes for 30+ year or so. The sound of a tube amp is discussed and also what influences the sound.

 

[Tarttett]

@Tom-s I haven't watched it yet, but thank you for the video. It's technical, objective, and accurate information that I want to hear about now.

 

[Redcarmoose]

https://wooaudio.com/amplifiers/wa5

https://wooaudio.com/amplifiers/wa3

https://6moons.com/audioreviews/eddiecurrent2/zana2.html

In my experience the W5 is really not that warm or classic tube sounding in whole. Also the EC Zana Duex and Woo Audio 5LE sounded pretty close to the same. The lesser price W3 absolutely has the indicative tube sound that tubes are famous for.

So it’s obviously design function but some really good tube amps are the best of both worlds. The more powerful ones have a great damping factor that goes even farther to clean up and detail out the lower midrange and bass response. Even with hard to dive headphones the more powerful tube amps like the W5 or EC Zana Duex will provide what sounds like a dB of extra bass, when in fact it’s just the bass getting clearer so it sounds like more.

Added to that the tube sound can have a great soundstage and imaging presentation that’s very 3D and different than solid-state. There is still going to be slight warmth but better tube amps have it in along the right places. To many hearing the better tube amps can be surprising as they really do sound clean and closer to solid state.

The W3 is an example of a lower cost tube amp that delivers much of the artifacts that we associate with tubes. Warmer with a slower and somewhat non-linear bass response. It’s this lo-fi blooming quality of some tube amps that can be endearing..........when in many ways it’s a form of distortion in a sense. Many tube amps have a nice smooth way of rolling off highs and have an indescribable magic that solid state struggles to ever reach. But just like many things, your going to need to love what they don’t exactly do correct to enjoy some tube amps. Where expensive amps like the W5 or Zana Duex are excellent performers basically doing absolutely nothing wrong.

 

[KC2020]

So it’s obviously design function but some really good tube amps are the best of both worlds. The more powerful ones have a great damping factor that goes even farther to clean up and detail out the lower midrange and bass response. Even with hard to dive headphones the more powerful tube amps like the W5 or EC Zana Duex will provide what sounds like a dB of extra bass, when in fact it’s just the bass getting clearer so it sounds like more.

Added to that the tube sound can have a great soundstage and imaging presentation that’s very 3D and different than solid-state. There is still going to be slight warmth but better tube amps have it in along the right places. To many hearing the better tube amps can be surprising as they really do sound clean and closer to solid state.

Well said. I've been enjoying tube amps for 50+ years at home and in the recording studio. The evolution of the best tube amps over the years has brought a few of them to the pinnacle of 'musical' while still being quite neutral in their sound.

As I write this I'm streaming Tidal to a Crane Song Solaris D/A and listening to the Sennheiser HD800S though a Quicksilver Audio Headphone Amp. This amp has to be the most neutral sounding pure tube amp I've ever heard. The dimension, detail and soundstage are amazing. The bass control (damping factor) is better than anything I've ever heard.

I use the Little Labs Monotor and various closed back HPs while tracking. It's quite an impressive solid-state amp, accurate and very enjoyable. But when listening for pleasure I can't wait to use the Quicksilver.

 

[Mikem53]

I don't think I've seen anyone not describe a tube amplifier as warm. Do tubes necessarily make sound warmer?

Tubes are also more pleasing to the ear when they distort, that’s why guitar amps are usually tube based as tubes distort with even order harmonics which are pleasing to the ear compared to SS amps which distort at odd order harmonics..