Are cheap valve (tube) amps as effective as expensive, if adding a touch of distortion is the goal?

[Westsounds]

It's the distortion we like right?

So is it just as effective to use any valve amp as its purely subjective on the listener what it's doing to the signal.

The terms harmonics are thrown around which i guess is technically correct, or worse still, liquidity, lushness, euphoric, spaciousness, 3D, colour and warmth. And all to more or lesser extents depending on the equipment/reviewer.

So if it can be done cheap like the example below (possibly the cheapest available and to tube roll) why do people spend small fortunes on the infinite combinations of other units out there. I guess it is because they can, and we all like different effects / tonality. But when solid state is technically better, why does this spiral of never being satisfied continue for some. Including myself, I guess I'm asking for much needed help with this part of the hobby

 

[somebodyelse]

It's all going to depend on implementation not price. There's an argument that any amp circuit that responds to tube rolling is a bad circuit - it ought to perform properly with any valve within nominal specification, not have its performance be a lottery. Some valve preamps manage this, and manage to have decently low distortion figures. Others fail by this standard, but that appears to be what you're looking for. A word of warning though - some of the cheap ones don't even have the valve in the circuit. They just power the heaters and/or put an LED under it - it's just there for decoration. You might like to look at the Korg Nutube too - a dual triode made using vacuum fluorescent display methods, and mostly used for its intentional distortion.

Personally I'd go for a clean system, then add distortion to taste using something like PKHarmonic so it's all under control.

 

[JSmith]

It's the distortion we like right?

Nah... high fidelity, minimal noise and distortion.


JSmith

 

[DanielT]

@Westsounds : It's the distortion we like right?

But when did audible distortion in tube amps become desirable? As far as I know, manufacturers of tube amps in the past emphasized the low distortion of their tube amps.

One example, this classic; Harman Kardon Citation II tube amp is approaching 70 years old. Note even feedback, which even now can be mentioned as negative by subjectivists but is considered positive by HK:

Careful listening evaluation of amplifier performance proves conclusively that extremely stable amplifiers with higher degrees of feedback provide a noticeable improvement in sound quality and a definite reduction in listening fatigue. This improvement can be attributed to lower harmonic and intermodulation distortion products, more linear phase characteristics, and improved transient response.

The quote can be found in the image with Technical Description below:

 

[Westsounds]

Thanks for the replies. I guess the harmonics I've experienced in the past with tube amps have wet my whistle so to speak. I've quite enjoyed the effect of some. There is like an echo reverb effect which I felt may have given it a spacial effect as well but it has been ever so subtle. But as you quite rightly point out it can be done other ways. That PK may be worth a look for me, and i will give some time to research it better. I have experienced a VST tube emulator with Win Amp that was actually pretty good and gave the same kind of effect as some of the best valve amps I've tried, even if it was kind of over emphasized. I also have an SMSL DAC which can add colour using tube settings, and again it does add an extremely subtle touch of flavour. I don't know why though I just find myself hankering after those little glass tubes again and sticking them somewhere in my audio chain. What is wrong with me!

 

[DanielT]

Thanks for the replies. I guess the harmonics I've experienced in the past with tube amps have wet my whistle so to speak. I've quite enjoyed the effect of some. There is like an echo reverb effect which I felt may have given it a spacial effect as well but it has been ever so subtle. But as you quite rightly point out it can be done other ways. That PK may be worth a look for me, and i will give some time to research it better. I have experienced a VST tube emulator with Win Amp that was actually pretty good and gave the same kind of effect as some of the best valve amps I've tried, even if it was kind of over emphasized. I also have an SMSL DAC which can add colour using tube settings, and again it does add an extremely subtle touch of flavour. I don't know why though I just find myself hankering after those little glass tubes again and sticking them somewhere in my audio chain. What is wrong with me!

But you have insight into how it works so then it is up to you whether you want to color the sound or not.
Also some vaccum tubes that light up are nice to look at.

By the way, Aiyima T20 tube pre amp. It hardly adds any audible distortion. So is it a too good or too bad tube pre amp?

AIYIMA T20 Tube Pre-amplifier Review

This is a review and detailed measurements of the AIYIMA stereo tube based balanced preamplifier. It was sent to me by the company and costs US $180. This is an unexpected and attractive design! I love the large and stylish volume control which can be managed using the supplied remote control...

www.audiosciencereview.com

 

[Westsounds]

But you have insight into how it works so then it is up to you whether you want to color the sound or not.
Also some vaccum tubes that light up are nice to look at.

By the way, Aiyima T20 tube pre amp. It hardly adds any audible distortion. So is it a too good or too bad tube pre amp?
View attachment 517904View attachment 517905

AIYIMA T20 Tube Pre-amplifier Review

This is a review and detailed measurements of the AIYIMA stereo tube based balanced preamplifier. It was sent to me by the company and costs US $180. This is an unexpected and attractive design! I love the large and stylish volume control which can be managed using the supplied remote control...

www.audiosciencereview.com

Subjective improvement in audio quality is always good, even if it comes by just looking at glowing tubes

 

[DanielT]

Subjective improvement in audio quality is always good, even if it comes by just looking at glowing tubes

In fact, one of the few hifi items I regretted selling was a 10 watt DIY tube amp (not built by me) that I bought for the cost of a hamburger meal in the 1990s. When I replaced the power tubes, EL90/6AQ5, they cost more than the amp itself.

Built in a sheet metal box. I drilled holes under it for better cooling. I was going to mount a small chimney to get chimney draft but unfortunately sold the amp before I installed the chimney.

It was a fun little tube toy.


Output transformers stacked on top of each other

 

[wwenze]

No, because the only thing that correlates with how audiophile an amp is is the price tag.

 

[Ropeburn]

But you have insight into how it works so then it is up to you whether you want to color the sound or not.
Also some vaccum tubes that light up are nice to look at.

By the way, Aiyima T20 tube pre amp. It hardly adds any audible distortion. So is it a too good or too bad tube pre amp?
View attachment 517904View attachment 517905

AIYIMA T20 Tube Pre-amplifier Review

This is a review and detailed measurements of the AIYIMA stereo tube based balanced preamplifier. It was sent to me by the company and costs US $180. This is an unexpected and attractive design! I love the large and stylish volume control which can be managed using the supplied remote control...

www.audiosciencereview.com

That one is a good example of why cheap tube (pre) amps are basically a nothingburger.

Look at that distortion spectrum: 3rd harmonic dominates, just like you'd expect from a fake tube circuit that actually uses opamps. Likewise 5th higher than 4th. It's typical solid state behaviour.

Amount and audibility aside, that's not "tube sound" in which 2nd and subsequent even harmonic is supposed to dominate the distortion spectrum.

 

[Jim Taylor]

Subjective improvement in audio quality is always good, even if it comes by just looking at glowing tubes

Some listeners do not crave an improved sound, but merely a different sound. That's a rabbit-hole with no end.
To wit: roller-coasters are fun, but if you had to take one to work every day, you'd get sick and tired of them very quickly.

 

[DanielT]

That one is a good example of why cheap tube (pre) amps are basically a nothingburger.

Look at that distortion spectrum: 3rd harmonic dominates, just like you'd expect from a fake tube circuit that actually uses opamps. Likewise 5th higher than 4th. It's typical solid state behaviour.

Amount and audibility aside, that's not "tube sound" in which 2nd and subsequent even harmonic is supposed to dominate the distortion spectrum.

And a tube pre amp should probably be a class A design (keep it simple, when not much power is needed), which supposedly gives those coveted 2nd harmonics with at the same time not so (audible?) pesky unruly 3rd harmonics,( plus higher up the scale uneven harmonics).
That compared to push pull tube amp designs.

In theory anyway. How it is with it in practice, you probably need to measure it amp by amp?

But on the other hand, if you want a lot
2nd harmonics it's easier to buy a transparent solid-state amp and just add as much as you want via the plugin @somebodyelse mentioned in #2 :

Announcing beta-test of PKHarmonic VST plugin

As discussed in a separate thread, this is a beta-test of a VST (Windows) plugin to allow you to dial-in an arbitrary amount of harmonic distortion while playing music with your favorite music player. Now you can enjoy that second harmonic without investing many thousands of $$$ into a tube...

www.audiosciencereview.com

 

[Ropeburn]

And a tube pre amp should probably be a class A design (keep it simple, when not much power is needed), which supposedly gives those coveted 2nd harmonics with at the same time not so (audible?) pesky unruly 3rd harmonics,( plus higher up the scale uneven harmonics).
That compared to push pull tube amp designs.

In theory anyway. How it is with it in practice, you probably need to measure it amp by amp?

Yes of course. Here's a nice one: https://www.audiosciencereview.com/...-tube-pre-amplifier-review.66604/post-2469867

But on the other hand, if you want a lot
2nd harmonics it's easier to buy a transparent solid-state amp and just add as much as you want via the plugin @somebodyelse mentioned in #2 :

Announcing beta-test of PKHarmonic VST plugin

As discussed in a separate thread, this is a beta-test of a VST (Windows) plugin to allow you to dial-in an arbitrary amount of harmonic distortion while playing music with your favorite music player. Now you can enjoy that second harmonic without investing many thousands of $$$ into a tube...

www.audiosciencereview.com

Always the best option. Freely adjustable, and actually gives you the distortion you want. Not sure whether it eats less power though, regular PCs are hungry. Better use an efficient mini PC or something. Lol

 

[raindance]

Tube preamps are always class A...

A tube amplifier typically includes transformers to couple to the speakers as well as power tubes. The example shown is NOT a tube amp. It's debatable, but some of us think the output transformers are what add the "magic" of tube amps - mushy, rolled off bass with accentuated mid bass on many speakers and rolled off treble, which emphasizes the mid-range.

A tube preamp, if poorly enough designed, can add even harmonic distortion that you may find pleasing but this is rare and typically a tube buffer, used in many cheap products, cannot. A cathode follower buffer adds odd harmonics (just like solid state).

Good circuit designers can design linear, low distortion tube preamps (which sound exactly the same as solid state except they add a bit more noise) but the magic art of designing ones that use poor circuits to add pleasing distortion is uncommon.

 

[Westsounds]

No, because the only thing that correlates with how audiophile an amp is is the price tag.

Great answer, how else can audiophiles justify they’re gear is better than yours

Some listeners do not crave an improved sound, but merely a different sound. That's a rabbit-hole with no end.
To wit: roller-coasters are fun, but if you had to take one to work every day, you'd get sick and tired of them very quickly.

True and then there’s the mix of all your experiences of equipment, thinking of the best bits and how can I have all that sound in one coherent whole with my next purchase. Or maybe the next holy grail bit of gear. As you rightly say Jim, a rabbit hole that never ends! Truth is it’s all just different.

 

[wwenze]

Other industries also use money as a measurement of performance

 

[DSJR]

In the UK, we had Croft preamps (until he passed away and left instructions that any stock or unfinished units were to be destroyed after his passing a very few years ago). These measured quite well, sounded great and transparent on the whole (sorry to fudge here, but the more sophisticated models did seem to make subtle details less 'buried' in the mix) on the whole and didn't change so much with tube rolling).

When the old Mullard/Philips concern that made CRTs for TVs ceased making them, a number of staff used the same basic modern long life tech as used in the CRTs to update some popular valves (TechTube brand?). The best prototypes performed well, but initial listeners found the sound too dry in nature (I suspect similar to solid state?). Some 'slight ringing' was introduced to satisfy this. The concern didn't last long sadly and I'm darned if I can quickly find reference to this concern

The TechTube Blackburn E813CC: A New Approach to Tube Design

We invite our readers to a return to the past, when the original Blackburn manufacturing site where Millard tubes were once made, was shipping the TechTube Blackburn E813CC - an engineering effort to redesign the ECC83 dual triode, claiming more accuracy and more consistency. "The famous...

audioxpress.com

Techtube valves/tubes

Hi. I'm new to this group so hello everyone. I have some first hand information about the new TechTube tube as I have been helping with its development and Andy Blades of Blackburn Micro Tech has given me permission to talk about it. I have been using some pre production E813CC double triodes...

www.diyaudio.com

I have serious doubts if valves can be used *cheaply* to any real effect other than visual...

 

[OldHvyMec]

It's the distortion we like right?

There is a certain amount of distortion that is fine, depending on the type of valve amp you choose. I prefer the sound of the older Mcintosh MC240s over most amps you can buy or tweak. I use the term tweak because many Cary valve amps can use a myriad of different valves, from 6V6 to KT99, with just a change of valves and a re-bias.
Many vintage Carys were switchable. I prefer A/B vs single ended. Many disagree, but Cary gives you the option. I use V12Rs for the simple reason that I can use between 4 power valves total (2 per side) up to 12 (6 per side), and like I said, from 6V6 to KT99 valves. OR from 12 watts per rail to over 100 watts per rail or per channel. It takes me about 10-20 minutes to swap valves, and most of the time is warmup.

Mcintosh on the other hand, in order to get the classic Mac sound, you have to do a couple of things to KEEP the sound intact. The unit has to be serviced FIRST and brought within factory specs. It usually requires a rebuild if it has been tampered with, and the standard PIO caps should be replaced with PIO caps, not the Polies you see in rebuild kits. Polies change the sound signature, and not in a good way. They last a long time, but so do good PIOs. The Bumblebee caps used in many of the MC240 were manufactured with some flaws that caused problems down the road. I believe they were manufactured in the US, where some were not, and didn't suffer from the same manufacturing boo-boos. I just happened to like the PIO that came out of Eastern Europe, mainly Russia, when we could get them. It is critical to use very well-matched power valves and certain small valves.

Typically, Telefunken, RCAs, and Mullards fit the bill, though some of the newer valve work just fine.

harmonics

Most valve amps have engineered features that cause them to be easier to listen to over extended periods, and they usually have a slight roll-off in the HF range. Both even harmonics and HF roll off make listening easier for a lot of the older music. Country Western, early R&R, and of course classic Jazz.

What you are looking at will NOT be a good representation of what you are looking for. Remember, with most valve amps have to be careful matching speakers. Unless you use the amp for mids and highs ONLY, most valve amps are not well known for great sub/bass. If you pick the right speakers, they can certainly do a good job on older music.

Don't waste your money on tube buffers or software that introduces "tube sound." Here is the reason why: you will always wonder if that is really what a decent tube/valve amp sounds like, and you are probably right to think that way. LOL

You don't have to jump off the deep end and spend a lot of money, but you sure can if you're not careful. Be patient and do a little research. After 50+ years of using tube/valve amps, I can honestly say they are the most fun and, when used for what they are good at, one of the best choices you can make for classic sound reproduction. They are not perfect, but they are the perfect imperfection when done right.

Regards

 

[DVDdoug]

...Outdated 1950's technology.

It's the distortion we like right?

Who is "we"? I don't like distortion in my audio system. Sometimes it's OK if it's part of the performance and intentionally part of the recording.

BTW - I've never HEARD distortion from ANYTHING that wasn't broken or overdriven. Obviously, some stuff measures better or worse, but it's rarely audible (at least to me).

There is no "one tube sound". If a tube amp has a "tube sound" it's going to sound different than every other tube (or solid state) amp.

You are more likely to get imperfect sound from a tube power amp than from a tube preamp because of the output transformer and "interaction" between the amplifier's output impedance and speaker impedance. Speaker impedance is not flat over the frequency range and if the amp's output impedance is too high (low damping factor) the impedance variations become frequency response variations. Sometimes you get a bump-up in the mid-bass range. Sometimes a boost in mid-bass is called "warmth" but "warmth" can also mean slight distortion.

I'm sure MacIntosh tube amps sound "perfect" like any good solid state amp, with no sound of their own.

Guitar players tend to favor tube amps because of the way they tend to "soft clip" and "saturate" when over-driven. (Solid state guitar amps generally have similar characteristics because that's what guitar players want.) But guitar amps are not high-fidelity. They have a "sound" and are "part of the instrument".

You wouldn't want to hear the whole band through a guitar amp, and you don't want the whole band over-driven and saturated. Most guitar players have their favorite guitar and their favorite amp.


P.S.
A distortion story...

Many years ago I worked at a radio/TV repair shop. I was working on a car stereo with distortion. After working on it for awhile and trying a few things I was no longer clearly hearing the distortion and I was wondering if I had fixed it... It had started sounding normal. I had to listen to something else to "reset" my ears & brain, then I could hear the distortion again. It's weird how the ear/brain adapt! It was such a strange experience that I remember it decades later! I assume we would also adapt to "slight pleasing distortion" and wouldn't hear it after listening for a period of time.

 

[DVDdoug]

The best prototypes performed well, but initial listeners found the sound too dry in nature (I suspect similar to solid state?). Some 'slight ringing' was introduced to satisfy this.

I read about something similar once. A guy was repairing a guitar amp and besides the repair, he found a "defect" in the circuit. I don't remember exactly but maybe it was a resistor that made the positive & negative halves of the waveform asymmetrical. He "fixed it" but the guitar player said it didn't sound right. He put it back the way it was originally designed and the guitar player was happy again.