What qualifies a "bad" tube amp, or what do you get from a more expensive tube amp

[computer-audiophile]

But the owners like the sound. Obviously we can't assess those dimensions here on ASR.

That is a diplomatic answer. Thank you for that!

It would be best to limit oneself to one's own real experiences with such things if one wants to judge them. There are indeed areas of a 'listening culture' that are not covered by ASR.

And now, please, no shitstorm, guys!

 

[robwpdx]

I don't object to people having stupid hobbies at all. I could be accused of that. But the tube-o-philes, and vinyl-o-philes and cable trestle-o-philes need to be reminded of reality. Just every once in a while. Also the full range (lowther) speaker-o-philes. Have I missed any?

Turntable fetish is ridiculous. Number 1 start with tracking your cartridge linearly. There was a famous AES paper measuring the distortion of radial tracking arms.

There is starting to be a revival of reel-to-reel fetish. The issue with consumer audiophile tape is that to do tape, you have to calibrate it, and professional Dolby for tape is a vintage item today. There are many more things robbing linearity from tape than there are robbing linearity from tube amps.

Like tubes, it is fine for artistic purposes when tracking or mastering to introduce tube distortion and compression for artistic purposes. I think several have said that.

There is some good work in DIY room conditioning using SMART software and a calibrated mic, then building traps and absorbers. For work, we had "Hidley rooms" with no parallel walls, the foundation set on sand and isolated from the building. There are other similar acoustically-designed room formulas.

 

[fpitas]

Anyways, the point of this thread was on how one regardless of our perceived utility of such might evaluate the objective merits of a particular tube amp for which distortions and colourations are intentionally designed. Quality of build, components, or soldering. Long-term reliability of the platform through which folks will be periodically replacing tubes. I suppose that every tube amp owner wants as low of a noise floor or crosstalk as possible. Then the question of how one would evaluate the quality of a transformer or tube that intentionally introduces colourations.

Otherwise, all things considering, I would be of the stance that after the noise floor is made to be low enough, the main thing you are probably sonically getting between a $1,000, $4,000, or $8,000 "audiophile" tube amp and their respective colourations is simply something different and exclusive, even if barely so.

Yes, that is my impression. Like different flavors of distortion. And to my mind, no longer qualified to be called high fidelity.

 

[fpitas]

That is a diplomatic answer. Thank you for that!

It would be best to limit oneself to one's own real experiences with such things if one wants to judge them. There are indeed areas of a 'listening culture' that are not covered by ASR.

And now, please, no shitstorm, guys!

If you like that sort of thing, I doubt anyone here has much to say. I mean, I like anchovies on pizza

 

[Mr. Haelscheir]

If you like that sort of thing, I doubt anyone here has much to say. I mean, I like anchovies on pizza

I am of the camp that Hawaiian pizza with ranch sauce is delicious.

Anyways, I suppose there isn't much left for this thread other than that we probably have no choice but to go by reviewers and other customers' word regarding build or component quality and whether they find the new auditory fragrance pleasing. Tubes, or specific implementations of such, being "more holographic", "dynamic", "clear", or "detailed" may or may not be a fantasy. Now, it probably would be cool if controlled studies could find that specific tube amp or transformer measurements do reliably correlate with certain perceptions of soundstage or imaging etc., and this would probably have more merit than attempting the same for solid-state amps which we know measure in a fashion that leaves the only remaining variable to perceptual bias.

 

[Mnyb]

It’s ok to like tune amps not a problem at all .

I have these usual objections.

Usually some tube snobs claims that there is mystical unmeasurable quality that science can’t explain in tube amps.

And it’s just assumed the distortion is always audible and or pleasing? I think it’s mostly inaudible and placebo and in blind test the user will pick a solid state amp for sound quality

Edit: What is clearly audible with some design or the fr response modification

 

[fpitas]

Usually some tube snobs claims that there is mystical unmeasurable quality that science can’t explain in tube amps.

Sure. Nobody pays that much for a perfectly normal amplifier.

 

[computer-audiophile]

Good sound - even with low distortion and noise - can be produced with both tube and transistor amplifiers.

I find a few other things fascinating about tube amplifiers.

Apart from the tubes themselves, which sometimes date back to the first triodes developed 100 years ago, the circuits are often very simple and use only a few components. This simplicity also allows for easy modification and customization, so that I can tailor the amplifier e.g. to the specific sound-sources and speakers. I always see this as the overall concept of my designs.

By understanding the underlying physical principles and optimizing the circuit design, it is possible to create an amplifier that is not only technically impressive, but also emotionally engaging. And the glowing filaments of the tubes themselves can create a sense of warmth and comfort, adding to the overall listening pleasure.

 

[robwpdx]

If this gentlemen is not on ASR, they would be a good contributor. They discuss distortion in tubes based on curve tracer data.

Vacuum Tube Curves in 3D​

 

[fpitas]

If this gentlemen is not on ASR, they would be a good contributor. They discuss distortion in tubes based on curve tracer data.

Vacuum Tube Curves in 3D​

Lots of the more serious designers use SIMs like Spice, too.

 

[computer-audiophile]

Nothing new, only visually more apparent presentation.

Yes, Spice is very valuable tool, and widely used. The simulation of my circuits and the later measurements have always agreed very well so far.

 

[mhardy6647]

I believe a bad tube amp is like a bad dog.

 

[spede]

But why use a tube amp at all?

Generally makes headphone sound smoother and more bassy, might work better on some than others.

 

[MattHooper]

Tube stuff is for idiots.

*puts hand up*

Where do I get my T-Shirt?

I don't object to people having stupid hobbies at all.

What's stupid about owning or enjoying tube amps?

I could be accused of that.

I doubt it. But then I'm not fond of calling other people's interests "stupid." (Well...except for Competitive Eating Contests...)

But the tube-o-philes, and vinyl-o-philes and cable trestle-o-philes need to be reminded of reality.

Which reality is that?

I like my tube amps and believe I'm pretty grounded in reality/rationality.

 

[egellings]

To me that looks horrid.

How it looks is in the eye of the beholder.

 

[egellings]

It’s ok to like tune amps not a problem at all .

I have these usual objections.

Usually some tube snobs claims that there is mystical unmeasurable quality that science can’t explain in tube amps.

And it’s just assumed the distortion is always audible and or pleasing? I think it’s mostly inaudible and placebo and in blind test the user will pick a solid state amp for sound quality

Edit: What is clearly audible with some design or the fr response modification

That's what they are! Tube amps are tune amps. That's the whole rationale.

 

[Chrispy]

How it looks is in the eye of the beholder.

Yep just this beholder's view of course.

 

[Cwopete5]

I have a "cheap" (by integrated tube amp standards) Black Ice Audio Fusion 3502S. I consider it a "good" tube amp in that:

1. It has a 30 second filament warm up time before applying high voltage to the power tubes. Some tube amps merely mute the input signals to give the appearance of a "soft" startup and pound the power tube with high voltage while they're cold.
2. It does not "eat" tubes nor blow up components (resistors and capacitors). Read the customer reviews with some of the cheap China HiFi offerings and you'll hear all kinds of horror stories about self-destructing tube amps.
3. If an output power tube does go bad, and they do wear out, the amp will detect the failure and go into self-protect mode by shutting down the high voltage and filament voltage.
4. It is dead quiet except at the highest volume. No transformer or 60 Hz hum whatsoever.
5. It is easy to bias the output power tubes with a DVM. Some tube amps provide a built-in meter without test points. If the built-in meter fails, you're out of luck.
6. I've rolled a bunch of power and preamp tubes over the years and it's like a Timex watch; takes a licking and keeps on ticking.

Now there's plenty of other more expensive tube amps out there that come with fancier features like auto-bias, but I see that more as a sales gimmick for the lazy person who doesn't care to understand or deal with biasing tubes. Because I'm a retired engineer who grew up watching the glow of audio tubes, I love to tinker with different tubes and bias settings to hear the differences in sound stage and tone. Yes, these are subjective non-technical terms, but that's what we "tube amp heads" are into. I enjoy it. After all, isn't that what this hobby is supposed to be about?

PS - I also have a Vincent Audio SV-500 Hybrid Integrated Amp with audio tubes on the preamp side and transistors on the output side. It still retains some of the "warmth" (I know, another non-technical term, sue me) without the hassle of biasing tubes.

 

[milosz]

Citation II powering Quad ESLs. I have also used good SS amps with these speakers, the sound is similar. The Citation seems to sounds a little less "tizzy" in the high treble. The Quads go down to very low impedance at 20 kHz (see below) and this can lead to a bit of harshness even on the best SS amps I've used. It's not a night & day difference, but I prefer the Citation. Other tube amps I've tried did not sound nearly as good as the Citation, or as the SS amps.

 

[egellings]

Citation II powering Quad ESLs. I have also used good SS amps with these speakers, the sound is similar. The Citation seems to sounds a little less "tizzy" in the high treble. The Quads go down to very low impedance at 20 kHz (see below) and this can lead to a bit of harshness even on the best SS amps I've used. It's not a night & day difference, but I prefer the Citation. Other tube amps I've tried did not sound nearly as good as the Citation, or as the SS amps.

View attachment 288137View attachment 288138

That amp has big butt bass.