What's all the fuss about tubes?

[smith101]

Wow, I just visited a high end audio shop that sells only tube electronics--even home theatre and CD players. This stuff is waaaay pricey. And the specs look terrible--only a few watts and lotsa distortion (Antique Sound, etc. ). They claim they are selling like hotcakes. I did hear a pair of small 2-way Magnepans with a subwoofer--sounded really open and smooth, but they only demo from vinyl! No digital! And tube stuff on ebay is going for astounding prices. Got a lecture on how digital is grainy, brittle, unmusical. Why is this happening???

 

[O'Shag]

I have three preamps. Two are solid state (Audio Research SP4 and Carver C4000T), and one is tube. I also own the Yamaha RX-Z9 which is one of the top receivers out there. My tube preamp (Audio Research SP6-E) clearly outclasses all of them. Its interesting for me to go through each as an evolution of sound reproduction, because it confirms to me that the tube technology although old (much more so than the current state of the art Yamaha), is fantastic. The SP6-E is a tiny bit more laid back than the SP4, but is highly detailed (much more than the others) and with a very large and accurate soundstage. Instruments and vocals sound more rounded with more body. I don't use vinyl. My tube preamp sounds fantastic with my Carver tube CD player, which is my second piece of tube gear. Although Carver made some OK CD players, they made two very special ones, both reference with two 6DJ8 EC88 Bugle Boy tubes in the output stage. I have yet to hear a CD player or combo (transport and DAC) that sounds better than mine (I own two because I thought it was so good). The tube stage gives this CD player more headroom, more dynamics. It sounds incredibly detailed and powerful.

My next planned buy will be my very first tube amp. I love the tube sound.

Hope this helps.

 

[UMD_terp]

Tube amplifiers tend to have very pleasing second order characteristics as opposed to their solid-state counterparts. You mention distortion... that is the key with tubes. Solid state amplifiers sound very harsh when distorted or clipped, but a tube's second order harmonics still sound good to the human ear.

 

[ruadmaa]

Tubes Sound Better???

The following is a direct reply by Sound and Vision that can be found on page 28 of the July/August edition:

"Okay, Internet, get this: tubes are a waste of money! They're hot, they're expensive, and one prominent manufacturer of tube equipment told me some years ago that the tubes themselves have something like an 80% failure rate. AND THEY DON'T OFFER BETTER SOUND. They have higher inherent distortion, are often obviously noisier, and offer much lower peak power ratings than solid-state equiment. They certainly don't last as long. So why put up with the bother? Sound & Vision

Doesn't look like Sound and Vision puts much credence to the superiority of tubes.

 

[Mudcat]

Somethings Burning

Sniff Sniff, I smell a very hot topic/arguement.

 

[markw]

this is like arguing pizza and chili dogs.

They are both comfort foods. Let's not confuse preferences with superiority.

 

[Rip Van Woofer]

If you value accuracy you'll go solid-state. If you want to listen to your music through the audio equivalent of "rose-colored glasses" and posstibly have a strong streak of nostalgia for retro-tech, then tubes can be appealing.

The so-called "harshness and graininess" (what the #*$! is "grainyness" anyway?) of digital is largely a matter of incompetence or carelessness on the part of the recording engineer, especially in heavily compressed pop music recordings. Dan Banquer has an article on the subject here, and it has been discussed on the forums. IMO, it's also a matter of 'philes with Luddite tendencies hearing things that may or may not be there. An all-too-common occurence!

There are three main characteristics of the "tube sound" (besides the soft clipping behavior) from what I've been able to ascertain:

1) Increased second-order harmonic distortion which basically adds a bit of brightness to the sound (especially in the midbass thru midrange frequencies - after that the harmonic is above the range of human hearing) by emphasising the first harmonic an octave above the fundamental tone.

2) A rolled-off treble response. This may account for tubes taming the "harshness" of digital. The faithful reproduction of the highest frequencies in digital vs. vinyl can ruthlessly expose the shortcomings of your tweeters. In other words, it's the speakers, not the source that are the culprit IMO.

By the way, many if not all "single-ended triode" tube amps in particular have output impedance and frequency response curves that look like a freakin' roller coaster. Not to mention power ratings of 9 watts or so. Accuracy? Fuhgeddaboutit!

3) High output impedance, resulting in a low damping factor. This accounts for what the "tubistas" approvingly call "bloomy" bass and what I call badly controlled bass.

As for clipping, if that's the problem you simply need a more powerful amp!

All of these characteristics can be reproduced by the designers of solid-state equipment should they so wish. In fact, Bob Carver reportedly did so in the 80's with something called the "T-mod" to one of his solid-state amps. For daring to demonstrate that all the sonic characteristics of megabuck tube amps could be reproduced by means of comparatively inexpensive solid-state gear he was pilloried by the high-enders, I have read. And to some extent he still does the trick in his Sunfire amps with the so-called "current source" speaker outlet, which consists of (ready for this?) a 1 Ohm resistor placed in series with the output. It mucks up the "transfer function" enough to roll of the highs a bit and (I think) decrease the damping factor.

The shop you were in is basically a temple to a particular sect of the high-end audio cult!

My Webpage has links to articles that touch on this matter further.

 

[O'Shag]

Yyyup.

I thought the same way until I gave tube gear a try. I am not hard of hearing, and can discern sonic differences as well as most others.

My tube preamp is better on all levels than my solid state preamps or the Yamaha. Its not just a little better. It is very noticeably better. It is MUCH more detailed. It is MUCH more dynamic. It provides MUCH more 3- dimentionality to the music I'm listening too. There is absolutely no audible distortion whatsover, it is clean and warm. It does not appear to colour the music at all, although scientific measurement might show otherwise.

As I mentioned previously I own two Carver SD/A390t tube stage( each has two 6dJ8 ECC88 tubes). I bought the second one because I was so absolutely impressed by how good this CD player is. Its MUCH better than my other players, three of which I paid 3 and 4 times the price of the Carver (one is a $2,500 player). Granted the Carver has a very sophisticated circuit which does wonders also, but its the tube stage that makes the greatest difference.

Her is a quote from an article I read...

'Briefly stated, a commercially viable number of people find that they prefer the sound produced by tubed equipment in three areas: musical-instrument (MI) amplifiers (mainly guitar amps), some processing devices used in recording studios, and a small but growing percentage of high-fidelity equipment at the high end of the audiophile market. These areas employ vacuum tubes of the type once known as receiving tubes, but now called simply tubes. Not only has the use of vacuum tubes in these fields defied the semiconductor tide elsewhere, but such use and demand has even surged in the course of the 1990s.

If cries of fraud and derisive comments about "magical sound" sometimes greet the use of tubes in audio equipment, there are also highly competent electrical engineers who see definite advantages in tubed equipment. An example is John Atwood, consulting engineer and owner of One Electron Co., Santa Clara, Calif. The erstwhile designer of application-specific ICs and other solid-state logic circuits has managed to transform his hobby of tube audio design into a full-time consulting business. In Atwood's opinion, "Some of the differences in the audio qualities between tubes and transistors have to do with the inherent physical properties of the devices and with the circuit topologies and components used with each type of device. There is no way around it: linear [triode] vacuum tubes have lower overall distortion than bipolar transistors or FETs, and the distortion products are primarily lower-order...the clipping characteristic of tubes is actually not much softer than transistors, but feedback tends to 'square-up' the clipping. Thus, the heavy feedback in most solid-state designs gives them worse overload performance. "A low- or no-feedback design can be driven harder without audible distortion," Atwood continued. "High feedback also can lead to transient intermodulation distortion (TIM), caused by clipping or slew-rate limiting within the feedback loop." [See table for a comparison of the attributes of tubes and transistors in audio applications. See also "Distortion under test".] Clipping distortion is not the only issue. In semiconductors, the shift of characteristics with temperature along with their relatively low maximum operating temperature has led to extensive use of Class-B amplifiers to keep power dissipation down. In many designs, the result has been audible crossover distortion, which often does not show up in published specifications. Those specs are typically based on measurements made at full power, where crossover distortion is at a minimum. Consumer tube amplifiers use Class-A or Class-AB designs, which have vanishingly low distortion even at low signal levels.'

 

[Rob Babcock]

Finally! The old "tubes vs transistors" is decided once and for all! Who'd have thought we could finally end the debate here at AH.

 

[jeffsg4mac]

I would like to hear what Dan B has to say on this. I am sure he has an opinion. Dan where are you? All I have to say is if tubes were better sounding than solid state than Krell and Levinson would be using them. They don't!

 

[NewYorkJosh]

Dangerous generalizations

Sounds like the audio store in the original post was promoting a rabid purism, and Rip Van Woofer strikes a complimentary dismissive position. Both, like most forms of zealotry, are reductionist and wrong. Wrong to say "all solid state gear sounds hard and flat" as it is to say "all tube gear has rolled off highs, undamped bass, and lots of distortion" - but that's the knee jerk reaction of both sides. 'Fact is that there is exquisite gear and low grade dreck on both sides of the debate. Sweet gear of either construction has more in common with each other than with the dreck of either. In the high end, you can get superb sound out of many different approaches - although their aesthetics and situations for which they are suited are quite different.

First of all, there's really two arguements going on here:
1) Tubed versus Solid State gain stages in preamps and amps. I'll focus on this, since this seems the meat of the thread.
2) Digital versus Analog. The analog purist rejection of digital is all-of-a-piece with the single-ended triode purist position. Even extreme audiophiles want the new music that only comes out on CD, so there's been a lot of hope invested in SACD and DVDA - but these are clearly still marginal formats. That being said, even redbook CD, now after decades of tweaking, can offer amazing sound with the right gear. Few audiophiles will argue digital is inherently bad; just that the redbook standards are too low resolution to compete with an ace turntable setup. However, eventually a higher resolution standard will come along and this issue will be put to rest. So I'll only focus on the amp debate.

My purpose here isn't to settle the debate, but to counter the kneejerk reductionists by offering a description of the major design movements within both camps so as to shed some light on the issue. Let me identify the major gain-stage divisions as I see them:

1) Mighty bass-king amp that can drive any speaker with iron authority tends to be sold state (Krell, Crown, Bryston, Outlaw audio, Adcom, Aragon, etc..). This is right in line with the conventional audio engineer perspective that measurable qualities are all that counts, so pour on the power. These kind of amps are great for difficult loads or really big systems. Clearly most Japanese receivers are in this tradition. I really don't have to do much to sell this angle - probably 95% of folks in the audio community adhere to this dogma.

2) High current, lower wattage solid state amps that strive for simplicity - (Pass Labs, 47 labs, maybe Harman Kardon to a less extent). These guys strive to get rid of feedback, extra gain stages, and a lot that extra control circuitry to get a clean circuit that sounds great. Pass used to make a class A monobock (Aleph 30) that weighed 100lbs but put out only 30 watts, all class A and with so much current it could drive almost anything and only one gain stage. It was extremely sweet and sounded fast and direct with amazing detail and dynamics.

3) Warm and tubey solid state. Solid state that aims for the "tube" sound (Carver, YBA, Mobile Fidelity, maybe Denon a bit). Liquid and deep is the watchword here.

4) Massive stiff Pentode tube amps with transformers. The conventional tube design from way back, gangs parallel groups of tubes to increase power, rated specs, and damping factor. (Conrad Johnson, Audio Research, Sonic Frontiers, Van Alstine, Dynaco, Macintosh). This used to be what most people thought was tube amps until single-ended came along. The sound can be warm and tubey, or tight and punchy. There tends to be that magic midrange. I have an Audio Research Classic 60 with 16 Soviet KT-90 tubes that sounds as sharp, full range, and bass slamming as a high-end solid state amp.

5) Transformerless (OTL) tube amps. The transformer has been eliminated and replaced with a bunch of tubes. This mojo is beyond my knowledge. These amps possess a special magic. Also they are impedence matched for some big electrostatics. These amps like high impedence - and with the right speaker they are positively lengendary with amazing presence, dynamics, immediacy and rhythmic drive.

6) Single-ended Triode minimalist amps. Goes for the minimalist aesthetic by having a single gain stage going through a single triode tube. This monolithic purity gets as much circuitry out of the way as possible at the cost of poor specs, rolled off treble, and loose bass damping factor (just like RVWoofer states). However I bet RVWoofer never has listened to a high end SET system. Enthusiasts have come up with all kinds of accomidations, mainly extremely sensitive horn loaded speakers like the Avantgarde Trios from Germany that can put out 101db with 1 watt. Midrange presence is amazing. Vocalists are in the room with an immediacy and power unobtainable with other gear.

So what? At the high end there has been a growing sense that global feedback and multiple gain stages muddy up the sound. There have been many design attempts to build simple, pure, circuits both in solid state and tube designs and some of them are truly magical. What is gained? Dynamics, clarity, subjective soundstage depth, spooky accurate imaging. Did I say dynamics? The jump factor and tingle are really what separates high end from mid. What is lost? Well, global feedback and multiple gain stages allow you to use lower spec parts and still get a circuit that measures very well. The paradoxical thing is that they don't sound as good as they measure. Pure circuits require fanatical quality of each part - this require manual testing of parts and the resulting gear is more prone to part failure. Most mid-fi receivers are built to hit spec sheet benchmarks at a low price. The only way to do this is with the redundancy and smoothing of feedback.

Where does this leave the solid state versus tube debate? It's irrelevant. What gets lost is the subjectivity of what defines a great amp. Someone who wants effortless power and gut wrenching bass (like in a big solid state amp) would really hate a small purist amp that failed in those departments - like a single ended triode. Someone who is looking for haunting presence and emotional connection might immediately connect with the single ended triode amp and not enjoy a big Bryston as much. Clearly many amps can swing both ways to some extent. The big Bryston is going to sound very good in a lot of circumstances, but head to head isn't going to match the SET in those luminous magical midrange qualities. Is there more compromise with the SET position? Sure. Does that make it wrong? Well it depends on what you want. To attack and dismiss someone with differnt tasts is just, in my opinion, rude. The single-ended purists (and tube enthusiasts in general) feel the need (like people who love Macintosh computers) to tell the mainstream about how great their more-expensive less-well-known gear is, in case they didn't know. For some it's a crusade. That's tiresome. On the other side there's the Audio Engineer dogma that anything isn't measurable or testable in a double-blind situation is just imaginary. Anyone who has lived with a variety of amps and an open mind know that is is just flat out wrong. Clearly all of these amp designs (and more too, that I've neglected to mention) have their strengths and weaknesses and require the right system matching...

I've owned over a dozen amps in the last 20 years, including both solid state and tube designs from Audio Research, Carver, Dynaco, Muse, Sony, Yamaha, Mobile Fidelity, Pioneer, and Adcom. Right now my home theater rig is a Yamaha HTR-5760 driving Gallo Acoustics Micros and my stereo rig is the aforementioned Audio Research Classic 60 drive ProAc Response 2s. Over the years, even with the cheap tube amps like the Dynaco Stereo 70 II (which cost a little over $600 for a 35 watt stereo unit), the tube amps have given great sonic satisfaction for the buck. The Adcom which cost about the same had better base but lower resolution and a more veiled midrange which made it a better amp for hard rock but inferior for most everything else. Tubes just can't be dismissed easily. Whatever the technical reason, there is something that really sounds great about a well implimented tube design. Everyone really owes it to themselves to actually go and listen at some point, rather than just dismiss.

However, given economies of scale, market forces, and the facts of technology, tubed gear is just more expensive these days. Mid-Fi receivers pack a lot of value into a little money. I've bought single digital cables that cost (much) more than my Yamaha receiver - but the Yamaha provides pleasure and does many things right. However, when I listen to a stereo recording on the Yamaha, and then on the ARC, there no comparison at all. The ARC has resolution and dynamics on a completely different order, despite having only 2/3rds the rated power. With the ARC I can hear many many things that are just missing with the Yamaha (thats the resolution). The startle factor, the alive JUMP factor is also a totally different experience with the ARC. Textures, colors, detail, a hugely wider deeper soundstage - all way better. BTW the ARC, while it only puts out 60 watts weighs almost 100 pounds and can heat a room running in class A with those big KT90 tubes running in Triode mode. This isn't a fair comparison - the ARC rig as a whole is vastly more expensive. If I had only $350 to spend on amplification, there's no doubt that I'd buy a Japanese receiver. There just isn't any competition at all at that level (literally). However, once you're spending a grand or two, things get very interesting and everyone needs to open their mind and go and listen to all kinds of gear.

 

[toquemon]

Tubes are expensive, unreliable and unefficient by themselves. The comparision would be unfair; it's like trying to compare the Ford 351 engine (the Mustang Mach1 had it) and the Honda VTEC. They're both very good engines but different.

 

[NewYorkJosh]

Tubes are expensive, unreliable and unefficient by themselves. The comparision would be unfair;

1) Expensive. No doubt. Tubes are fairly esoteric equipment. The economies of scale tilt towards surface mounted IC OpAmp based equipment. There's no arguement about the value offered by low cost receivers. Once you pass a certain threshold of cost (around a $grand I'd say), however, this arguement goes away. Once in rarefied air, the arguement is ultimately about subjective enjoyment and tubed equipment really holds its own.

2) Unreliable. Excuse me? Tubed equipment is by no means unreliable. I have two tube amps at the moment that have worked fine for years and years with no problems. I grant that tubes eventually degrade performance as they wear out after thousands of hours of use. The remedy is tube replacement which is basically changing a lightbulb with some bias twiddling. The military maintains lots of tubed equipment to be used in the event a nuclear strike's EMP destroys all that IC based stuff.

3) Inefficient (not unefficient). Granted - tubed equipment tends to be biased more towards class A which is wasteful, but sounds wonderful. Also, tubed equipment doesn't have nice standby modes - you have to turn it off when not in use. But let's be honest, is efficiency more important than sonics? That's throwing the baby out with the bathwater - which is, in effect, what we've done.

The comparison is by no means unfair. This whole thread is about what the fuss about tubes is. The fuss is that tubed gear sounds amazing. This fact flies in the face of a lot of objectivist dogma, so it stirs up a lot of defensiveness. Ultimately, I urge everyone to go listen to some tubed gear. While I resist the stereotypes, there is some truth to the rap that the tube sound is warm and lush with amazingly deep soundstage and rich realistic sense of presence to voices. There is magic midrange to counteract the weaknesses that often accompany: looser bass, a tendency to roll off highs. Subjectively, the strengths so outweigh the weaknesses - decisively so. Few who seriously demo tubed gear can dismiss it (even if they ultimately don't choose to buy it).

 

[toquemon]

1) Expensive. No doubt. Tubes are fairly esoteric equipment. The economies of scale tilt towards surface mounted IC OpAmp based equipment. There's no arguement about the value offered by low cost receivers. Once you pass a certain threshold of cost (around a $grand I'd say), however, this arguement goes away. Once in rarefied air, the arguement is ultimately about subjective enjoyment and tubed equipment really holds its own.

The Denon 5805 and the Yamaha Z-9 will outperform tubes with ease. I heard a pair of tube amps of Margules Audio (U280SC) and i think they sound very cool, but not enough to beat the amps from above, specially in price. (http://www.margules.com.mx/index_margules.htm)

2) Unreliable. Excuse me? Tubed equipment is by no means unreliable. I have two tube amps at the moment that have worked fine for years and years with no problems.

Lucky you!

3) Inefficient (not unefficient). Excuse me, English is not my mother language.

The fuss is that tubed gear sounds amazing.

sounds very good, not amazing.

This fact flies in the face of a lot of objectivist dogma, so it stirs up a lot of defensiveness.

i preffer the objetivist dogma than the subjetivist dogma. At least with the objetivist dogma i can prove what i'm saying.

Ultimately, I urge everyone to go listen to some tubed gear.

Yes, it sounds cool.

 

[Rob Babcock]

The "objectivists" obviously haven't cornered the market on dogma, NY Josh. Good chance the ol' tubes vs solid state debate was old before you were born, and I doubt this thread will reveal any startling new information. If you like your tubes, great. If someone likes SS, that's cool, too. You needn't be defensive if others don't agree. Be forewarned, even a cursory examination of this site will reveal the forum is stacked with engineering types and "objectivists."

You might also want to investigate the new digital amps. At first blush, the closed minded might assume digital amps would exhibit all the cliches attributed to CDs, but nothing could be further from the truth. The guys who're snapping up most of the low powered Tripath amps are mainly tube guys who love the tube sound, but are tired of the heat, cost & maintainance. Many have likened the ICEPower & Tripath amps to tubes; many claim to get tube "air" & "bloom" with SS "slam". Just ask Ed at The Horn Shoppe what his customers are driving their Model 1's with. Sure, he still loves his ol' trusty SET (the logo, "Little Miss Triode" ain't going away anytime soon), but the Tripath is taking the horn community by storm.

One forum veteran was so enamored with the Boulder Modded Panasonic '45 that he very nearly replaced his tube/hybrid AVA gear (all $5k worth!) with that cheap receiver ($300 retail, mod is $700). After months of comparisons, he eventually decided the added tube warmth of the AVA gear was marginally better, but to this day he considers the modded Panny very near the equal of his tubes. The Panny ended up knocking $3-$4k worth of AVA gear out of his HT rig, where it still resides.

I don't run a single full range driver, but I love my Tripath Powerwave, and I'm a happy convert to the digital amp. They're knocking down a lot of dogmatic preconceptions.

 

[mwheelerk]

Contemporary Middle of The Road

I have to admit my taste are more middle of the road and more contemporary technology. I love the potential of high resolution multi-channel music. I gave up my albums for cds and I am prepared to give up cds for sacd, dvd-audio, etc. My most "esoteric" equipment has been Parasound amp and processor, Rotel amp and processor. Otherwises I am more of a Denon reciever, Paradigm speakers kind of guy. Now this isn't "chopped cheese" equipment but certainly not considered high end.

I also didn't get tubes. I wandered into a shop here in the Phoenix area that specialized in tube gear, amps, pre-amps, cd players, even one sacd player tube driven (Shanling). The owner was very open to discussion without putting down my interests or equipment. He played for me a tube amp kit (it sold for $139!) that delivered only 3 watts per channel. It was fed by a Shanling CD player (about $1700 I think) and a pair of Quad speakers (going for $1200). I have to tell you I was amazed with the warmth and openness of the sound. I have returned on three other occassions and listened to tube amps again. I must say it has given me cause to consider a music only system using tubes. I will still maintain my other system for home theater, but I am seriously considering this move. My only pause is the fact that I would like to incorporate multi-channel into the music system and I don't know if such a tube amp exists and if it does if it would be within my budget range. In building such a system I would consider as much as $2000 for an amp (I don't really understand this yet but I know many tube amps can be directly driven by a line source without the need for a pre-amp), about $1000 - $1500 for a source player for cds and at least sacd and maybe up to $3000 for speakers. Ideally I would like to get away with half of that cost across the board so those figures are absolute max numbers.

 

[Polkfan]

I still say that people who spend alot of money on a piece of equipment, regardless of what it is (tube vs. solid state) feel that their equipment must be better since more money was spent on it. In some cases this may be justified, but to me it always is a trade off because a $6000 amplifier or receiver doesn't sound 10x better than a $600 one no matter how you look at it which is why mid-fi sells. But snobbery still exists. The American Golden Rule is bigger, faster and more expensive is always better isn't it?

 

[Rob Babcock]

The Butler 5150 is a 5 Ch Tube amp (or Tube Hybrid, can't recall the topography). It's fairly powerful (I want to say something like 150 Wpc X 5?). Can't recall the price, though. Not cheap, I do remember that.

 

[RaT]

I am greatful that my pallete has never been able to decipher the difference between fine expensive wine and fine cheap wine. I have found my ears can't do it either be it expensive sound equipment or good quality relatively inexpensive equipment. I consider it a blessing.

 

[Leprkon]

As does your checkbook