If "Tube Sound" Is a Myth, Why Tubes?

[Multicore]

As a practical matter, most engineered tube amps are transparent.

Well-engineered hi-fi tube amps are transparent by definition because, imo, hi-fi implies transparency.

 

[fpitas]

Maybe. In some cases I expect your right, consumers get confused my marketing baffle-gab. But I don't think it's the whole story. I think there's also an esoteric attraction. See my reply to Keith above and my comment about bowties here. Among the pleasures of esotericism is feeling special by belonging to a group of initiates that have knowledge that the uninitiated lack.

Well, I'll comment that there is no objective way to consider bowties. And I think you agreed with my point inadvertently:
Among the pleasures of esotericism is feeling special by belonging to a group of initiates that have knowledge that the uninitiated lack.
These are non-technical people who lack the knowledge to honestly say that. They have been brainwashed by salesmen.

 

[Galliardist]

Well here’s a tube amp from a highly reputable firm that was clearly engineered.

Luxman SQ-N150 Review (Tube Amplifier)

This is a review and detailed measurements of the Luxman SQ-N150 hybrid integrated amplifier with phono stage. It is on kind loan from a member and costs US $3,295. Can you say pretty? I knew you could! :) Love the elegant front panel with VU meter. Nice set of balance and tone controls are...

www.audiosciencereview.com

well, probably need to specify that the sound was engineered rather than just the case, but the point still stands.

 

[Galliardist]

Well, I'll comment that there is no objective way to consider bowties. And I think you agreed with my point inadvertently:
Among the pleasures of esotericism is feeling special by belonging to a group of initiates that have knowledge that the uninitiated lack.
These are non-technical people who lack the knowledge to honestly say that. They have been brainwashed by salesmen.

There is a lot of "knowledge" around that has absolutely no basis in reality. It's not just audio.

Excuse a lack or examples, most of them are in the two subjects that we aren't allowed to discuss here

 

[Multicore]

Very nice sound, but the total idle power consumption off the amp was little above 300W.

Oh my, that is a lot. Why did you want to build it? And what was nice about the sound?

 

[fpitas]

They were making good tube amps when I was born. Somehow they've lost the formula, through incompetence or just because they're making "audiophile" crap.

 

[Ron Texas]

There is a tube sound. Frequency response is rolled off at the extremes of the audio range and there is a lot of 2nd order harmonic distortion.

 

[Multicore]

There is a lot of "knowledge" around that has absolutely no basis in reality. It's not just audio.

I should think that alluding to esoteric knowledge was a common feature of the sales and marketing of home audio gear since early on. What I'm now proposing is that somehow high-end audiophillia emancipated itself from mere service to the practicalities of people enjoying music and elevated the gear be the end in itself and object of desire by defiantly emphasizing the esoteric aspects, like: If you can't hear the difference then you don't get it yet, keep working on it hard and long enough." And spending. And with luck one day you'll understand a Herb Reichert review and maybe even be able to talk like he does.

 

[Multicore]

There is a tube sound. Frequency response is rolled off at the extremes of the audio range and there is a lot of 2nd order harmonic distortion.

In many classic guitar amps there's also compression. The power supply sags on the attacks when playing loud, reducing gain on those peaks. Done right it sounds great and is a necessary feature of a decent modeller.

I assume that's a characteristic of some hi-fi tube amps too but I seldom see it mentioned.

 

[NiagaraPete]

well, probably need to specify that the sound was engineered rather than just the case, but the point still stands.

Perhaps you could provide an example of a "sound" engineered tube amp that has transparent measurements.

 

[SIY]

Perhaps you could provide an example of a "sound" engineered tube amp that has transparent measurements.

Look, for example, at any of Tim deParavicini’s amps, including the ones he did for Luxman like the MB 3045. Any of my amps, Pete Millet’s Engineer’s Amp, Morgan Jones’s Bevois Valley or Crystal Palace, Quad, Williamson, Mullard, Harman-Kardon Citation, Marantz 8 or 9, McIntosh…

Again, to be clear, I’m talking about sonic transparency. If you want top measurements, Krone-Hite.

 

[SIY]

There is a tube sound. Frequency response is rolled off at the extremes of the audio range and there is a lot of 2nd order harmonic distortion.

That’s single ended, whether tube or transistor. Engineered tube amps have pretty flat frequency response .

 

[fpitas]

For the non-tubers here, I'll explain that audio engineers gave up on single-ended triode amps around 1940. Their re-emergence is strictly an audiophile thing. As SIY refers to, they drive the output transformer and speaker asymmetrically of necessity, and so have even-order harmonic distortion.

 

[MattHooper]

Wise words.

I like the looks of my valve amp, but not the wait while it warms up, so it is on a shelf rather than in the system...

That brings up a question for me.

Though I've owned my tube amps (CJ) for over 20 years, I have never cared about the idea any gear, even my tube amps, need to "warm up" before "sounding
correct" or whatever. I just turn 'em on and listen. (Well, if using my tube pre-amp it does have it's own set "warm up" before it clicks on ready for use...a minute or two I think).

That said, over the past year I've had the occasional impression that the sound changed during, say, the first 20 minutes or so of listening. Like the sound starts off a bit "darkened" with less highs, and then it suddenly opens up a bit and gains the usual sparkle.

My initial impulse is to attribute this only to imagination, some change in my perception happening. But I wonder if I'm wrong: is there some technically plausible explanation for how the sound might audibly change during some warm up period with a tube amp? (Or preamp?)

 

[fpitas]

That brings up a question for me.

Though I've owned my tube amps (CJ) for over 20 years, I have never cared about the idea any gear, even my tube amps, need to "warm up" before "sounding
correct" or whatever. I just turn 'em on and listen. (Well, if using my tube pre-amp it does have it's own set "warm up" before it clicks on ready for use...a minute or two I think).

That said, over the past year I've had the occasional impression that the sound changed during, say, the first 20 minutes or so of listening. Like the sound starts off a bit "darkened" with less highs, and then it suddenly opens up a bit and gains the usual sparkle.

My initial impulse is to attribute this only to imagination, some change in my perception happening. But I wonder if I'm wrong: is there some technically plausible explanation for how the sound might audibly change during some warm up period with a tube amp? (Or preamp?)

Have you looked at the idle bias over time?

 

[egellings]

Wise words.

I like the looks of my valve amp, but not the wait while it warms up, so it is on a shelf rather than in the system...

With tube amps, the appearance may be a bigger draw than the performance is.

 

[egellings]

That brings up a question for me.

Though I've owned my tube amps (CJ) for over 20 years, I have never cared about the idea any gear, even my tube amps, need to "warm up" before "sounding
correct" or whatever. I just turn 'em on and listen. (Well, if using my tube pre-amp it does have it's own set "warm up" before it clicks on ready for use...a minute or two I think).

That said, over the past year I've had the occasional impression that the sound changed during, say, the first 20 minutes or so of listening. Like the sound starts off a bit "darkened" with less highs, and then it suddenly opens up a bit and gains the usual sparkle.

My initial impulse is to attribute this only to imagination, some change in my perception happening. But I wonder if I'm wrong: is there some technically plausible explanation for how the sound might audibly change during some warm up period with a tube amp? (Or preamp?)

Agree. As soon as my home brewed tube amps & preamps warm up and internal voltages & currents stabilize, the sound is as good as it will get. I still could sometimes swear that the sound improves over time, but I suspect that my ability to enjoy the sound is what's warming up. Stable amp, mushy biological creature...

 

[MattHooper]

Have you looked at the idle bias over time?

Not in direct relation to that issue. My amps have a red light associated with each biasing pot and if I've put in new tubes I pay attention to ensure those are dialed right (they don't flash when the bias is correct). But other than that I don't have any detailed method of checking idling bias.

 

[fpitas]

Not in direct relation to that issue. My amps have a red light associated with each biasing pot and if I've put in new tubes I pay attention to ensure those are dialed right (they don't flash when the bias is correct). But other than that I don't have any detailed method of checking idling bias.

A lot of amps have test points you can get a DVM on.

 

[ta240]

That brings up a question for me.

Though I've owned my tube amps (CJ) for over 20 years, I have never cared about the idea any gear, even my tube amps, need to "warm up" before "sounding
correct" or whatever. I just turn 'em on and listen. (Well, if using my tube pre-amp it does have it's own set "warm up" before it clicks on ready for use...a minute or two I think).

That said, over the past year I've had the occasional impression that the sound changed during, say, the first 20 minutes or so of listening. Like the sound starts off a bit "darkened" with less highs, and then it suddenly opens up a bit and gains the usual sparkle.

My initial impulse is to attribute this only to imagination, some change in my perception happening. But I wonder if I'm wrong: is there some technically plausible explanation for how the sound might audibly change during some warm up period with a tube amp? (Or preamp?)

Can resistor and capacitor specs shift based on their temperature and enough heat building up in it to affect them?