I think I found why some people like high distortion tube amps and some don't

[Chr1]

I agree that a warm sound is a distorted sound and not solely limited to tube amps. Lots of Class As do this . Some people like harmonic distortion.

However, I think that most people who use tube amps, use them specifically for their warm sound.

Personally I think you'd have to be nuts to use one that doesn't colour the sound. If you want fully transparent, the last thing you should be using is a valve amp.
YMMV.

 

[PaulK]

I disagree strongly!
First of all there are plenty of tube amps that offer clear undistorted sound.
Secondly I prefer an amplifier that offers detailed undistorted sound anytime over one that distorts the sound.

The tube amp I designed is so stable a 10 kHz square wave only shows a minor change after the amp is loaded
with a 2 uF capacitor. It is a great amp to drive Quad ESl's.
That amp is still as it was when designed 50 years ago. The only thing I replaced were the power tubes.
The driving stage consists of three E80L SQ tubes. Amazing what 22 Watt of tube amplification can do.

 

[Chr1]

Fair enough, but I guess we need to define "clear" and "undistorted". My point was that if this is your goal, there are much easier ways to achieve it nowadays.

By the way I have a tube amp myself.

 

[Snoopy]

.
Tubes burn out. Tubes need warming up. It's a constant struggle.
The "return of tubes an vinyl" is purely money-driven. Keep buying our tubes, which will burn within a year. Keep buying vinyls, which will start skipping very shortly after the purchase.

My Cayin HA-2A needs like a minute to warm up the tubes. It uses tubes that where used in TVs and Radios.
Should last well over a year

Most of my LPs are used Japanese pressings from the 70s.. so well over 50 years on some.
No skipping and no snap crackle pop.
(ML stylus and waxwing phono stage).

I’m everytime blown away how good this „outdated“ stuff sounds and how much more I enjoy it than my digital stuff sometimes.
(Difficult to admit for someone that invested in a roon lifetime license, m4 Mac mini and lots of digital purchases and own rips)

 

[Juanrdp]

I’m everytime blown away how good this „outdated“ stuff sounds and how much more I enjoy it than my digital stuff sometimes.

I think that here maybe you are mixing two different things, I myself use vinyl in an old 1200 that i could grab and a tube amp (a mid cost caying one) and in comparison with a full digital chain the difference isn't huge but when you use the vinyls you need the time, the mood, just more often than not listen a whole album just as the artist thought of the themes and the order with the physical medium in your hands, maybe the lyrics, and mainly you only make that, listen the music.
That's a huge difference compared for example with listening the same songs on a random playlist of 4 hours while making any other thing and without paying constant attention.

 

[majingotan]

My Cayin HA-2A needs like a minute to warm up the tubes. It uses tubes that where used in TVs and Radios.
Should last well over a year

Most of my LPs are used Japanese pressings from the 70s.. so well over 50 years on some.
No skipping and no snap crackle pop.
(ML stylus and waxwing phono stage).

I’m everytime blown away how good this „outdated“ stuff sounds and how much more I enjoy it than my digital stuff sometimes.
(Difficult to admit for someone that invested in a roon lifetime license, m4 Mac mini and lots of digital purchases and own rips)

I have a DIY Aegis tube amp. Measures decent for a OPT tube amp, sounds subjectively just as great as the modern SOTA amps. Very quiet too and much less sensitive to WiFi routers or smartphones nearby it. IMHO, the subjective sound quality never really improved for many decades as we've already reach subjectively great sound far back in time by listening to these 50's circuit design SET amps currently being sold on the market right now, but measurements did improve though correlating that audibility thresholds for distortion are much, much less sensitive than what measurements suggest.

 

[DVDdoug]

Fair enough, but I guess we need to define "clear" and "undistorted".

I'd avoid the word "clear", but we know what "undistorted" means. Most amplifiers don't have audible distortion unless they are over-driven into clipping.

Once we have audible distortion, there are different kinds and varying severity. Not all tube amps with "tube sound", sound the same. If you like that kind of thing you have to find an amp with a kind of distortion you like. And of course you have to avoid good tube amps that simply amplify like a good solid state amp.

Tubes tend to soft-clip when over-driven which is one reason guitar players tend to favor tubes... They like the way they sound when "saturated". Most guitar players have their favorite guitar and their favorite amp.

I agree that a warm sound is a distorted sound and not solely limited to tube amps.

To me it used to mean a mid-bass boost. ..,.Until I found out that to some people it means slight-pleasing distortion. So now I try to stick to defined words like bass, treble, frequency response, distortion, and noise.

A lot of old tube radios were in fairly-large wood cabinets and they had some of that mid-bass resonance as well as high-frequency roll-off. And those days, radio was mostly AM which has limited high frequency range.

 

[Chr1]

Indeed. As with any amplifier, I think that it is always good to see a graph displaying it's FR. As you say, with tube amps there is often a mid bass boost and a general downward slope/cutoff in the higher frequencies. Often, though not always, there is also marked spiking where the various harmonics are too. Though this shows a FR that is not particularly hifi (flat), it is often what makes them sound good to some people.
Perhaps controversially, I reckon the spikes of the harmonic distortion is just as much part of the sound and appeal (again, to some), as the general FR curve. The fact that their clipping characteristics are way more benign is an added bonus. YMMV.

 

[egellings]

I was just watching a Veritasium video about audio illusions. In the first segment they explain the trick of using the harmonic structure of a note to trick the brain into hearing a fundimental that is not there. Well as a lot of people in the comments pointed out. Not everybody hears that phantom fundimental but just distortion added to the true fundimental of the tone that's played. I only hear a distortion and no phantom fundimental and I do not care for tube amps. I like a cleaner signal. This must be the same meganism why people say tube amps sound "warm". Those people hear that phantom fundimental shifitng the tone of the amp down making it more mellow of a sound.

Well, the tube amps do get quite warm when in use, and maybe some of that rubs off on the sound, hey? Tube amps can be made to have low distortion so that no 'tube warmth', outside of envelope temperature gets added. A 300B S.E. amp will butter up the sound, while a well designed circlotron type using a judicious amount of negative feedback, won't. Some listeners will like the 300B sound, and if they can enjoy the music with that, then fine. They won't, however, be able to brag about any technical superiority of that approach.

 

[DanielT]

I have a DIY Aegis tube amp. Measures decent for a OPT tube amp, sounds subjectively just as great as the modern SOTA amps. Very quiet too and much less sensitive to WiFi routers or smartphones nearby it. IMHO, the subjective sound quality never really improved for many decades as we've already reach subjectively great sound far back in time by listening to these 50's circuit design SET amps currently being sold on the market right now, but measurements did improve though correlating that audibility thresholds for distortion are much, much less sensitive than what measurements suggest.

View attachment 473816

A headphone amplifier. Nothing wrong with that I just thought it was a power amplifier.
I missed that it says 1mV into 32ohm.

Aegis DIY Tube Headphone Amplifier

Hello, I am releasing a DIY tube amplifier project, the first complete DIY project I've released on this forum. The amplifier is called Aegis. I started my DIY journey on the headphone forum Head-Fi. I have something of a tube DIY blog there where I catalog all of my ongoing projects. For a...

www.diyaudio.com

 

[PaulK]

Thank you for such a wide range of reactions on my statement about tube amplifiers.
I did not expect to poke the bear this easily.
I respect everybody's views, experience and personal taste.

Let me explain how I found an amplifier that suits me after extensive research.
I am happy with a custom designed tube amplifier. That amplifier needs a pair of output tubes every 3000 hours.
The phase inverter and input tubes last over 6000 hours. They are Philips tubes from the SQ series.
SQ tubes are Long Life tubes made for professional applications. The design uses three E80L and two KT 88 tubes.

It was pure coincidence I discovered this idea behind the design of tube amplifiers.
I found an old American textbook about designing tube amplifiers.
The writer explained two important principles:
1. Try not to exceed 35 dB negative feedback in single loops.
2. To improve stability in wide band power amplifiers with negative feedback low phase distortion is essential.

Low phase distortion means a wide frequency range. A minimum of 500 kHz band wide is required.
To achieve that the use of penthode tubes is advisable. These tubes were often used for video applications.
With that in mind I designed a tube amplifier with excellent qualities.
I was educated in electronic engineering at the time tubes were still used. Yes I am that old.

The bottleneck in tube amplifiers is the output transformer.
I found an output transformer with wide range, suitable for KT 88 penthodes.
That transformer allowed penthode and ultra lineair mode for the KT 88 tubes.
After a couple of tests I decided to use triode mode for the KT 88 Tubes.

Clear and low distortion is for me high definition. This design offers high definition.
The amp is ultra stable. It has no problem to handle the load ESL speakers impose on an amplifier.
Power output is a mere 22 Watt which does not recommend the use of speakers with low efficiency.

Most of my working life was dedicated to record music as balance engineer.
My interests in recording and reproduction of music lead to some astonishing discoveries.

 

[DanielT]

A good tube amp sounds clear and certainly not colored as many listeners still believe.

Hello and welcome to ASR.

Well constructed/designed with a high probability it is so. In any case if we have, let's say minimum 60 dB/ 0.1% SINAD throughout the entire frequency range, and flat FR as a requirement for a tube amplifier not to color the sound.
But then another question will arise. If the tube amp does not color the sound, then why a tube amp? Tube amplifiers are usually quite expensive. There are many modern class D amplifiers that can handle the aforementioned requirements for a reasonable amount of money (plus you get a lot of power as well).

For someone knowledgeable in electronics to have tubes as a DIY hobby, I understand. Fun to create something of your own. It has its own value. However, buying a commercial tube amp that does not color the sound, I have a hard time seeing what the point would be. Usually very expensive for the few watts you get. If we are talking about tube-based power amplifiers. Good and transparent tube-based pre amps/headphone amplifiers do not have to be that expensive.

 

[FrantzM]

Please explain? I thought he was credible?

+1

 

[PaulK]

I guess I need to explain a bit more about the background of this amplifier.
The amp was designed and built 47 years ago.

We were not even thinking about class D amplifiers in those days.

 

[PaulK]

I agree with the thoughts of DanieT.

Tube engineered amplifiers were not a hobby for me 47 years ago.
That was the year I designed and built the tube amp I mentioned here.

Since I use that power amp I never felt the need to look for something else.
Every 4-5 years a pair of new output tubes is all it takes to keep the amp in good condition.
The E80L tubes used for the input stage and the phase inverter last much longer.

I tested the amp with a square wave to check stability under all kind of loads.
A 10kHz square wave was reproduced well. The output only changed marginally after loading the amp with a 2 uF capacitor.
Not a trace of instability to be seen. THD is well below 0,1 % . In the range from 60 Hz to 8 kHZ it is considerably less.

 

[DanielT]

I guess I need to explain a bit more about the background of this amplifier.
The amp was designed and built 47 years ago.

We were not even thinking about class D amplifiers in those days.

I agree with the thoughts of DanieT.

Tube engineered amplifiers were not a hobby for me 47 years ago.
That was the year I designed and built the tube amp I mentioned here.

Since I use that power amp I never felt the need to look for something else.
Every 4-5 years a pair of new output tubes is all it takes to keep the amp in good condition.
The E80L tubes used for the input stage and the phase inverter last much longer.

I tested the amp with a square wave to check stability under all kind of loads.
A 10kHz square wave was reproduced well. The output only changed marginally after loading the amp with a 2 uF capacitor.
Not a trace of instability to be seen. THD is well below 0,1 % . In the range from 60 Hz to 8 kHZ it is considerably less.

Here on the forum, hifi enthusiasts gather, but then it can differ between us in what we want to invest in/ interests us regarding hifi. If we take amplifiers, the majority on ASR seems to be most focused on new class D amplifiers BUT there are quite a few who like and have vintage amplifiers/receivers, even tube ones.
It's a hobby where you can be interested in what you want and find rewarding.

Then there are those, like me, who mix new with old. Speaking of tube amps and mixing new and old: There are those who have bass boxes that play up to around 300Hz -500Hz that are powered up with modern class D amplifiers, the rest above 300-500 is taken care of by speakers that are powered up by a tube amp (a pretty good solution I think if you are going to have a tube amp in your hifi solution).


It's fascinating with old tube amps. It's audio and hifi history. Yes, the price can be high BUT for example a:

Used Harman Kardon Citation II Power amplifiers for Sale | HifiShark.com

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Can most likely maintain its market value for the coming years. A new modern class D amplifier, on the other hand, how much in value has it lost after five years, for example?

Or a Williamson tube amplifier in good condition, its depreciation? Taken care of and serviced by a knowledgeable within electronics (you should be if you are going to have such an old tube amp) then it will not lose in value. Perfect for powering up a pair of compression drivers that have a sensitivity of around 108 db:

'Does anyone have a Williamson tube amplifier?'

Apr 7, 2023

Or have had, listened to a Williamson tube amplifier? Impression?

Are they available?
What can one, in reasonable condition, cost?

I could really imagine having one. Mostly for its HiFi history. Not as a main amp but in some nice secondary system. Then together with a subwoofer + LP/HP filter sub-speaker. Speakers that the Williamson tube amplifier would like to drive.
I might add that when I say have such an old amplifier as a general tip, you should be knowledgeable about electronics or, as in my case, have a friend who is knowledgeable (I help him with other things). Taking...

• DanielT
• Replies: 72
• Forum: Amplifiers, Phono preamp, and Analog Audio Review

• 

More about mixing, or one thing does not exclude the other. Most people know that modern lossless streaming, even Spotify (which is not yet lossless) has better sound quality than vinyl, but that doesn't stop many people here from using vinyl, or lossless streaming and vinyl:

'Nice turntables. Attached picture is an absolute requirement.'

Oct 5, 2021

Post a picture of a vinyl lathe that you think looks good.

Performance information, optional. I am most interested in some nice pictures. How vinyl sounds is of secondary importance. For me anyway.

Feel free to tell us about your youth's vinyl player. Take a trip down memory lane.
Something positive, for example, do you remember the first record you bought for your own money? Or something negative, for example those damn grounding problems and the hum sound that never really disappeared despite how many wires you pulled into the heating element or when you saw with a tear in your eye...

• DanielT
• Replies: 1,354
• Forum: Turntables, Phono Amplifier, Cartridges Review

• 

 

[PaulK]

One aspect of vinyl is often forgotten.
It gives us a chance to enjoy historical recordings.
I like to mention the Mahler Symphonies by the KCO under the late Bernard Haitink.
Recorded in the sixties without Dolby using Agfa PER 525 tape. The tape hiss does not bother me.
How do I know? I was present at those sessions.

You mention the Williamson amplifier. The output transformer I used was also used for the Williamson amplifier.

 

[sceptical1]

I have heard mainstream mono 50s recordings equivalent in fidelity to the best modern recordings. The method is what exceeds even today's superior playback components. Reverb and track limits count alot for realism.

 

[PaulK]

I beg to differ. Analog equipment of that era was limited in quality to start with the frequency range registered.
That was only the recording part.

Improvements in replay equipment let you enjoy these recordings within the limits of the equipment used 70 years ago.

 

[sceptical1]

That quality available at the time is enough to satisfy me.
By improvements do you mean manipulating the original recording to eliminate noise,etc.