Audio Amps: Glass tube or Solid State ?

[RonRyan85]

I have used many tube amplifiers and those using solid state
electronics in my Hi-Fi Stereo music hobby over the years and
now use a 80 watt output Carver receiver/amp. I have read in
some magazines that most music-audio fans perfer to use the
expensive glass tube amplifiers that cost thousands of dollars
because they say the sounds produced are better, more dynamic,
more true to the concert hall sound but to my ears, there is not
a whole lot of difference between tube amps and solid state ones
in sound/music except the cost of all of these high end amps.

What do you use and what is your opinion of this?

[brandon11983]

Can you say "opening Pandora's box?" Asking an audio nut if they like tubes or solid state gear is like asking a car nut Ford or Chevy. I personally am a devout solid state guy. I cannot quite pinpoint what I do not like about tubes, but something about their sound just does not sit well with me. I am a very critical and discriminate listener, so I love the extremely, painfully, somtimes disgustingly detailed sound of a really nice solid state amp like a Naim or Meridian. The others at my store are all tube whores and say that vocals sound more natural on tubes. I feel the exact opposite. I may or may not be wrong, but that is just the sound I am particular to. Solid state also gives quicker and more powerful dynamics. As you know, solid state gear is just that, solid-state. A transistor can switch on and off much faster than a tube can heat up. Solid state gear also has more "oomph" behind it too. The bass out of them is tighter and more impactful.

These are just my humble feelings on the matter, you may do with them as you please.

[MSD]

I'm no expert, but I always like the sound of tubes better than solid state. The big thing I notice is that guitar distortion always sounds less synthetic on tube amps, and the same with high frequencies.

[BadNick]

Take your pick. Then you can make it sound to your liking either way. There is no one right answer, that's an elusive fantasy.

IMO, the balance between all your components and how they interact is more significant than tube vs solid state; I'm talkiing about the whole chain from first input to speaker output. Some of what you said about tube vs SS sound are stereotypes and maybe applies to some older tube equipment. No matter what sound you prefer, I'd bet I could put together a tube driven setup and a SS setup that you would like. But I think a good solid state setup is probably gonna cost less and be more practical for most. I'm not a fan of what I'd call the "old traditional" tube sound even though it has it's positive points too; and even there, old triode tubes sound different than pentodes etc.

I've had all sorts of SS and tube stuff throughout my component chain. For about the last 15yrs or so, I'm using and happy with a tube preamp (custom modified Audio Research SP6B) with a SS amp (modified Threshhold S300-II) but I find that cartridge changes and how I amplify the cartridge (moving coil with or without various step up devices vs moving magnet) and the character of the speakers make more significant differences than the type of amplifiers. How CD's sound is different too but I think less complicated since there are less pieces in the chain.

About less sythetic sounding guitars, it's funny when I was selliing my old solid state Crown D150 amp many years ago, I had a line of guitar players outside my house bidding the thing up above what I was even asking for it. Those guitar players said they really liked how the D150 made their guitars sound; this was both electric and amplified acoutic guitars ...I don't know what to think of that since I'm not a musician.

One thing about amplifier distortion that I have floating around in my head for better or worse is that ...this is an opinion not necessarily absolute fact... tube amps generate more significant odd order harmonics (like 3rd order) vs SS amps are making more even order harmonics (like 2nd order). Human hearing seems to prefer the odds vs the evens. But like I said above, other factors wash out these differences in 99.9999% of systems.

Here's a reason to go tubes: years ago a comforting experience with a Beard P100 tube amp I had for a while was the amount of heat it gave off = I literally had to turn the heat off in that room! Those big old KT88 tubes could almost heat my entire house and the aura and glow of the tubes was magical. But that doesn't make it better or worse than solid state.

[JJRousseau]

Tubes may be better but for the $$$, I'll take solid state any day. Put the savings in to a better source components or speakers.

[JJRousseau]

Tubes may be better but for the money I'll take solid state. Put the savings in to a better source components or speakers.

[Mephisto2]

All I can say is that my brother is the studio engineer for one of the largest, most successful bands in the world, and he swears by tube amplifiers. The band refuses to use anything else for most of their work.

Mr Mephisto

[exploreyourself]

Oh, God, this has the potential to turn into a holy war. It's like asking which is better, Macs or PCs. That said, it's still a valid question.

Here's my take: as long as you have good quality amps (flat frequency response, good distortion figures, etc) and are operating each amp within it's power envelope (not coming anywhere close to clipping) you shouldn't hear a difference!

There is no mystery to this stuff - I've been in a position for the last few years where I have access to test data for literally thousands of different amps, preamps, etc. The key, IMHO, to understanding why well-designed (this is important) amps sound different lies in three areas:

1. Do they really sound different - or do you just think so? Ive seen a number of double blind AB and ABX listening tests where amps were indistinguishable from one another as long as they were not total crap. If you know what you are listening to your brain will strive to hear a difference and often create one where it does not exist. It's a very powerful effect and I didn't really believe it until I experienced it myself and witnessed it in others.

2. Are you operating the amp within its power envelope? Music (particularly on well recorded albums that haven't been overly compressed) is extraordinarly dynamic. If you are listening at a volume that even remotely approaches "a bit loud" you will probably be shocked to know how much power it takes to reproduce a piano without inducing a bit of clipping in the amp. It's something on the order of 50W-100W, depending on the sensitivity of your speakers. I don't have the numbers in front of me right now, so please excuse this hand-wavy explaination.

Even very small amounts of clipping are detectable by the ear. Tube amps clip more gracefully than solid state amps - so if both amps are clipping the tube amp will sound better in those conditions. Accordingly, for the same perceived sound quality a tube amp can clip more than a solid state amp. When a solid state amp clips it literally cuts off (hence "clips") the peaks of the waveform. Tube amp clipping looks more like compression - sort of squeezing the waveform while keeping the same general shape. Be very wary of manufacturer's quote power outputs, especially on less expensive gear. This goes double for any sort of home theater receiver product. There are all kinds of games that can be played to grossly inflate an amp's power rating.

But, as long as you are using amps powerful enough for your sepakers, room size, and listening level this shouldn't come into play. But like I said above - it comes into play more often than most people suspect, I suspect.

3. Your speakers and the effect they have on the amp. Yes - your speakers effect what's going on in the amp in addition to the other way around. It's just a fact that, due to their design, solid state amps are way better at driving low impedance loads. If you have demanding speakers (electrically speaking, that is) you will almost certianly be better off with a sold state amp.

In the end - I'm a fan of any well designed amplifier. Pragmatically speaking - I recommend solid state amps when asked. They require much less maintenance (tube amps need the bias checked every so often, and you will have to replace tubes), and for the same sound quality you will spend much less on a solid state unit than you would have to for a tube amp. But, tube amps do look cool.

One final thing - guitar players and live bands often use tube amps. This is usually due to the distortion that the tubes introduce into the music. Many people find the sound of this distortion pleasing, which illustrates another point: it's as much about taste as anything else. But - there's a difference between deliberately introducing distortion during the performance/recording process and unintentionally introducing it during the playback. If you duplicate the distortion of the performance/recording process you will "double up" on the distortion and that's probably not what the artist intended. My goal is to be as original to the performance of the artist as possible. Otherwise it's like going to the museum with colored glasses - you might not mind the look but you aren't seeng the artist's work.

[stonegrody]

Tubes, tubes, TUBES!!! Mmm...the sound of a tube amp is like sonic panty remover. There are effects that you have to buy to try to replicate the tube sound on a solid state amp. Solid State has a couple of benefits but not enough to match the sound of a tube amp. Sure, the tubes have to warm up and they will eventually need replacing but they are so worth it.

[brandon11983]

Originally Posted by stonegrody

Tubes, tubes, TUBES!!! Mmm...the sound of a tube amp is like sonic panty remover. There are effects that you have to buy to try to replicate the tube sound on a solid state amp. Solid State has a couple of benefits but not enough to match the sound of a tube amp. Sure, the tubes have to warm up and they will eventually need replacing but they are so worth it.

If I wanted the effects of a tube amp, I wouldn't buy an effects box or some shit, I'd buy a damn tube amp. But I don't want to, because I do not like tubes. There is no such thing as a perfect amp. Tubes have some things they do better than solid state, and solid state amps can do things better than tubes. Tubes have smoother midrange and a softer roll off up top, but solid state has tigher and more accurate bass, and they are extremely revealing. My co workers all say tubes sound more natural on vocals (they're probably right), but they are all analog-heads and like that sound. I am a full on digitalophile, and I like the cold unforgiving digital sound. If the guy in the studio farts when recording, I wanna hear it.

[Nelson]

You cant hear the difference between a 'tube watt' and a 'solid state watt'.
A watt is a watt. The only sonic give away occurs when a tube amp is clipped. You can make a solid state amp sound like a tube amp with less than $1 in parts.

Nelson

[pixelbend]

Originally Posted by Mr Mephisto

All I can say is that my brother is the studio engineer for one of the largest, most successful bands in the world, and he swears by tube amplifiers. The band refuses to use anything else for most of their work.

Mr Mephisto

Hell, now I'm curious can you tell us the band? Or at least elude?

[portereight]

First off audiophiles and cult members have more in common than either would care to admit.
The human ear does seem to enjoy the non linear distortion characteristics of a tube amplifier, but without good speakers, its all for naught.
I once had the experience of being in a living room designed for an audiophile. The entire house was built with the ultimate goal of reproducing sound properly. The walls and ceiling contained achingly high end soffit mounted speakers. The room's furniture was designed, chosen, and placed for its ability to diffuse or reflect sound to such a degree that the beyond massive granite coffee table was used to reflect certain frequencies from a certain speaker to recreate ambiance. The sound was so close to real it was spooky. The power amp being used to demonstrate this was from Radio Shack. No this was not the amp that would be ultimately used, it was brought onsite by one of the speaker providers. Pretty good evidence of the relative importance of speaker versus amplifier.

[zenmaster10665]

exploreyourself:

Thanks for the info, it was a good read.

Personally, as a guitarist, I love tube amps for creating music, but I havent been exposed to enough tube amps in listening to music to make an educated statement on which I think is better....

I have always owned sold-state and love them. the NAD i am listening to Led Zep on right now sounds amazing.

[brandon11983]

Originally Posted by Nelson

You cant hear the difference between a 'tube watt' and a 'solid state watt'.
A watt is a watt. The only sonic give away occurs when a tube amp is clipped. You can make a solid state amp sound like a tube amp with less than $1 in parts.

Nelson

Sorry Nelson, I agree with some things you say, but to say that tube amps and solid state amps sound the same is preposterous. There are even differences between differing amps. For example, a Parasound 125wpc THX Ultra2 certified amp sounds very different from a Naim of similar power. A Rogue Audio tube amp (very solid state sounding) sounds completely different from an Innersound or Shanling.

[Nelson]

http://www.carsound.com/UBB/ultimate...1;t=022175;p=1

In sum: A tube amp will sound the same as a solid state amp when both are compared in linear opperation. Add a $.10 resistor to the output of the solid state amp and it will sound similar to the tube amp driven to non linear operation (wich is the only time you hear the 'tube sound')

Its a never ending argument LOL.

[supafly]

I'am building a tube amp myself as a project for school. It's almost finished. When it's finished i'am going to do several messurements in a professional auditorium. These messurements will than be compared to a solid state amp. I'll keep you guys updated.

Here is a picture for you
http://www.xs4all.nl/~gschep/SBW71/Buizen%20versterker/Foto's/Nieuw/IMG_0103.JPG

[Nelson]

What type of measurements will you be taking?

Using a 'professional auditorium' has nothing to do with recording any measurable differences in sound characteristics. Save yourself the trouble and do the 'tests' on a test bench.

Good luck with your project - keep us posted!

[jujueye]

I'll be painfully wishy-washy here. A combination of tubes and SS can capture most of both worlds. Don't feel like you have to be all tube or all SS. I think the best combination I have ever heard was a tube preamp with an SS amplifier. Plus the SS CD player. It was really amazing. And RonRyan: tubes are not necessarily mroe expensive. You might even build some tube gear from some place like Bottlehead.com or something. I like tubes. I've had SS for such a long time, and tubes really relax the whole musical picture for me, add some drama, and allow me to listen much longer into the evening than my all SS system. 2cents. Yeah.

[brandon11983]

Juju!! Glad you see you back!! Where you been man??

[supafly]

@Nelson
The following things will be measured (and maybe some more):

-Frequentie response
-THD (total harmonic distortion)
-Crosstalk between channels
-Input CMR (Common Mode Rejection)
-Damping factor
-Input impedance
-Input sensitivity
-Slew rate

I'll keep you updated. Thanks for the support.

[portereight]

'professional auditorium'
It sounds as if you plan on measuring these things "in air". While it is useful to measure real world results, this method will raise the bar on the method of measurement involved.
It would seem that to achieve any meaningful numbers you would need to perform the test in an Anechoic chamber rather than an auditorium to avoid echo creating phase problems misleading your measurements. The choice of a laboratory grade speakers and microphones is a greater can of worms. Microphones and Speakers exhibit more variation than tube amps vs. solid state ever would. Then there is speaker loading difference between tube and solid state making direct amp output measurements about as difficult as mic and speaker readings.

I sincerely will you good luck with the details of project

[Mephisto2]

Originally Posted by pixelbend

Hell, now I'm curious can you tell us the band? Or at least elude?

Very very big and very very Irish.




Mr Mephisto

[supafly]

I have come to the conclusion that i have used 'professional auditorium' incorrect. The testing is done in the SA (stage accompany, for info check out http://www.stage-accompany.com/) test facility. Sorry for the misunderstanding. The loading difference between tube and ss is solved by a transformer.

[merkerguitars]

Well if it was a guitar amp.......tube all the way..nothing distorts better than a tube amp

[hilbert25]

Originally Posted by Mr Mephisto

Very very big and very very Irish.




Mr Mephisto

You know, that was the first band I thought of when you made the initial comment....

And in response to the thread: I can definitely tell the difference in terms of tube vs. Solid State. I myself have always been leaning toward SS, but recently hearing a tube headphone amp has changed that a bit. I think I'll always like SS better for speakers, but powering headphones, I could see myself with a nice tube amp. I listened to a bunch of grados through a nice tube amp and it just seemed right.

[supafly]

I'am now near completing my tubeamp project. After analysing the tube's datheets and output transformer, I conclude that the total harmonic distortion of the tube amp is expected to be many times worse than for a ss amp. Mainly because of the output transformer. The messurements will be done in the new year, than I can be 100% positive.

For most tube headpnone amps you don't need a output transformer. This probably makes quite a difference.

[flat5]

Certainly the tube amp will have more distortion. Great care with the output transformer and circuitry is required and that is a big part of the extra expense of a good tube amp. The output feedback network, and balancing can make a big difference here.

supafly, you don't mention non-harmonic distortion tests, such as weird mixing products. You should do two tone tests too.

other tests you might consider:

Test freq. responce at just under clipping.
Pulse tests might be interesting. (overshoot, under shoot, sorta like slew rate, I guess)

You might test the noise floor at zero volume and full gain with input terminated.

What will be the dynamic range before clipping with a stated noise floor?

How critical will the load impedance be? (test at 2 to 16 ohms in 2 ohm steps at half power, for instance) test damping? various distortion tests.

just some ideas to keep you busy :-)

I wonder what tubes you are using? what circuit? point to point or circuit board wiring?
reply if you want to.

I would think the output transformer, a very good power supply, some low noise tight tolerance little components, careful feedback network, and common ground point (or lack of loops) is the big deal here.

[jujueye]

Let me jump in again here. What are you really going to do with it? If you're just going to use it for music reproduction, the VERY best instrument YOU can use will be your own ears. It may measure incredibly in every possible test, but if it sounds liek crap, it won't really matter. Once it's built, just listen to it. Tubes always measure worse, but that soft clipping is what makes them sound so nice.

You might also throw these questions around at http://www.bottlehead.com.

Finally, Nelson, I know what you're getting at with your description of adding at 10¢ resistor...but please tell me your use of the word "similar" was not real! If that were really the case, every ss amp manufacturer would be doing it...and we wouldn't be having this conversation! LOL! I'll agree that the first watt is the most critical. How about that, then? (!)

[flat5]

tnx for the link jujueye.

http://www.bottlehead.com/et/bottleh...logy_story.htm

Plenty I did not know.

[jujueye]

Ah, you'll be in trouble now flat5!
Seriously, though, the forum there is amazing. Spend some time digging through and you'll see just how much information is stored there. Lots of truly helpful and technically adept members. Build a kit! I built the Foreplay preamp kit and I have to say it truly kicks ass. I think its because the circuit is so simple. With a few tweaks, it borders on greatness.

[longbough]

Originally Posted by RonRyan85

...but to my ears, there is not a whole lot of difference ...

I think you answered your own question.
The amp itself is just one item in the chain. It has to be evaluated in the context of a complimentary music source (turntable/cartridge, reel-to-reel, CD player etc.), transducers (cones, electrostats, horns, ribbons, hybrids, etc...) and cables (solid core, twisted copper etc...). In any case it's not so much a question of "better" or "worse." Most high-end afficionados will tell you that various amps are simply characteristically distinct. Only part of that "character" is a function of frequency response, harmonic distortion, impedence etc... the rest is a matter of personal taste.

I used to follow "the numbers" as a guide to evaluating equipment until I put aside the literature and just went to listen to various systems and figured out my own preferences. And the more expensive amp (or loudspeaker, or player, or cable...) wasn't necessarily better to my ears. I have heard some great tubes, but I'm not willing to put up with the inconvenience for the sake of music.

Still, it's not just a matter of the "Emperor with no clothes." There ARE differences between amps. In a side-by-side comparison some recordings will reveal this more than others. Many studio-mixed heavily synthesized pop CDs might not sound much different in different systems. On the other hand, a well-engineered recording of a live concert could reveal dramatic differences.

[flat5]

jujueye says "Build a kit! I built the Foreplay preamp kit and I have to say it truly kicks ass."

I'll read some of the forum. Not really a serious interest of mine.
If I really wanted to build something, it would be another 80-40-20 meter SSB receiver.
The one I built in the 70s is gone now. Still miss it :-)

The amp I use (found on the street - that's Amsterdam for you) is a Luxman L-30.
2x30watt - Built from 1976-1978. picture here, five rows down on right side of screen.
http://www.hificlassic.dk/

[jujueye]

No problem, flat5. Maybe I'm just addicted to solder fumes... But do hit the forums. A big brain dump going on 24/7 there.

The Luxman: cool, man! Go Luxy!

For ronryman: another thing to consider with tubes: you can always change the sound of a tube rig by simply changing tubes. There are a lot of places still manufacturing or selling old tube stock. And they do not all sound the same. This, as you know, cannot be donw with ss components. Just an fyi.

[Catmandu]

Doesn't the fact that changing tubes will change the sound imply coloration? My feeling is that tubes are normally laid-back and graceful where SS is bright. I personally prefer the brightness because it allows me to choose speakers that integrate with it. Speakers can't spit out a sound that doesn't exist. But they can eliminate unwanted sounds. Additionally, I have found that SS amps tend to be quite a bit more bulletproof.

A question for those of you who mentioned familiarity with professional recording: are live shows all SS these days due to the reliability of the equipment?

[jujueye]

Catmandu - whooee - that could spawn another huge thread! I suppose that gets back to the question of: what is the right sound? With stereo gear, we are trying to reproduce what was recorded at the studio or site. Without having access to that gear, then its a tough call. Shooting for a flat frequency response doesn't do too well either as it usually sounds bland. So are we coloring the sound to be more pleasing or to make it more like the original sound? I'm not trying to make this more difficult, but it's a tough question! I'll think some more about it and try to get more info to you.

As far as tubes sounding laid-back, I can safely say there are tubes that strive to be clean and accurate like an ss sound. With the wrong speakers, these could burn your eardrums just like ss! On the other end of the scale, there are tubes that sound like what we all remember: smooth and buttery. Like any audio gear: component matching is key. And if the current tubes don't sound great, start shopping for more!

[shakran]

The trick to buying audio is to get whatever sounds best to you. Go listen to the tube amps, then listen to the solid state amps. Use the same CD on both. Make sure it's one you're familiar with. Make sure they're driving the same speakers. If the tube amp sounds so much better that it's worth the extra expense TO YOU, then buy it. Don't let some audio snob tell you you HAVE to buy it because it's what all the cool geeks are buying this year.

IMHO tubes sound a little better than solid state, but they don't sound so much better that I can justify spending hundreds and even thousands of dollars extra for them. I'd rather put those dollars into buying music - after all, if you sink 80 grand into a stereo (and when you get into high-end tube amp territory, it's pretty easy to do that) but can't afford any albums (note I did not say CD's or records, to avoid opening THAT can of worms) to play on it, then there's not much point in having bought it.

[supafly]

Originally Posted by flat5

Certainly the tube amp will have more distortion. Great care with the output transformer and circuitry is required and that is a big part of the extra expense of a good tube amp. The output feedback network, and balancing can make a big difference here.

supafly, you don't mention non-harmonic distortion tests, such as weird mixing products. You should do two tone tests too.

other tests you might consider:

Test freq. responce at just under clipping.
Pulse tests might be interesting. (overshoot, under shoot, sorta like slew rate, I guess)

You might test the noise floor at zero volume and full gain with input terminated.

What will be the dynamic range before clipping with a stated noise floor?

How critical will the load impedance be? (test at 2 to 16 ohms in 2 ohm steps at half power, for instance) test damping? various distortion tests.

just some ideas to keep you busy :-)

I wonder what tubes you are using? what circuit? point to point or circuit board wiring?
reply if you want to.

I would think the output transformer, a very good power supply, some low noise tight tolerance little components, careful feedback network, and common ground point (or lack of loops) is the big deal here.

The tests will be:

-Frequency response
-THD (total harmonic distortion)
-Crosstalk between channels
-Input CMR (Common Mode Rejection)
-Damping factor
-Input impedance
-Input sensitivity
-Slew rate

The two tone test and the load impedance test you mentioned are quite interesting suggestions.

The tubes I'am using are two E88CC's for the driver circuit and eight EL36's for poweramplification. The EL36 tube was commonly used in black and white TV's but works well for audio too.

THe output tranformers I use are 3A524's they have quite a nice freqency responce and are made by Amplimo. This is a famous tranformer manufacturer from The Netherlands (www.amplimo.nl).

The circuit design was done by myself. I can post the schematic and some pics in a few days if you're interested.

[Painted]

Originally Posted by shakran

IMHO tubes sound a little better than solid state, but they don't sound so much better that I can justify spending hundreds and even thousands of dollars extra for them. I'd rather put those dollars into buying music - after all, if you sink 80 grand into a stereo (and when you get into high-end tube amp territory, it's pretty easy to do that) but can't afford any albums (note I did not say CD's or records, to avoid opening THAT can of worms) to play on it, then there's not much point in having bought it.

You took the words out of my mouth. Sure, tube amps sound a little better, but it's not really worth all that cash and unreliability.

That being said, you can build your own tube amp for a relatively low cost.

[Nelson]

Explain to me the desire to have an under powered amp that sounds best when clipped?

For me, a SS amp with plenty of dynamic headroom - let the 'golden ears' gather around the tubes and tell stories about speaker wire, optical cable burn-in, and magic power chords LOL