Axiom Home Page Forums General Discussion Technical Questions Tube amps vs solid state with todays technology

Since this board has become my "audio for dummies" school, I'd like to know the following:
Given today's technology, what is the most significant imapct on performance/sound between tube and solid state amps of comparable quality? If there are differences, are they more noticable at different price points or are they a constant? I know the differences were signficant at one time (like 30 years ago), but then it seems to me I would listen to a gillion dollar MacIntosh versus a $1000 Nakamichi or something. I also know there are strongly held views, but is there the same kind of blind testing that Alan and sometimes Sushi and John K have referenced re: other components?

Solid state amps basically reproduce whatever you give them. If your source sucks, the sound will suck. Tube amps, on the other hand, color the sound. Tube enthusiasts find that coloration more enjoyable to the strict reproduction of the source. Audio being a subjective experience, you can't really claim one is better than the other. It's just a matter of preference. My suggestion would be to demo one and see if you share this impression before buying.

Hi Semi_On, My question was really academic, I'm not in the market. Thanks

Dharm, in my view tube amps represent an obsolescent technology and there's no good reason to seriously consider them. The distinguishing factor affecting most tube amps is a much higher output impedance(an ohm or more)compared to solid state amps(less than 0.1 ohms typically). This can result in the output "following" the swings in impedance of the speaker being used and therefore deviating from flat frequency response. For example, where a speaker has one or two large impedance peaks in the bass area, the tube amp would have a slightly elevated response at those points, which could be interpreted as "warmth", although in fact it's an inaccuracy. There's also a difference in the distortion characteristics of single-ended tube amps that make the onset of distortion less objectionable than in push-pull amps, but it's still distortion. Where the impedance or distortion effects don't create significant differences, the sound is identical.

I actually heard the pretty much the same thing from a speaker designer:

"Tube amps can do strange things to speakers, especially the highs. They are very susceptible to impedance variations, especially lower power models."

Hi fellas

Just laughing after reading your posts. I think y'all should put away your Nobel Prizes, get out the Q-Tips, put away your preconceived prejudices and kick back with a nice tube amp system.

Music reproduction is more than amplifier specifications, although to listen to some of you, the world is a very simple place - all solid state amps sound the same and are better than "obsolete" tube amps.

Find a nice Antique Sound Labs integrated, or some Manleys, a fine source and some nice Axioms actually listen to it, and tell me good tube amps are "obsolete," or inaccurate.

There are so many aspects to cover, but here are some of at-random $0.02 from a geeky music lover who used to build DIY tube amps in his youth...

First, like JohnK, I subscribe to the thoughts that, when it comes to the amplifiers, the sonic quality is essentially 100% measurable. I do NOT say the same for the loudspeaker sound, which I still believe has so many complicated aspects that even tomorrow's cutting-edge measurement systems cannot completely cover every attribute of sonic quality. This is especially true if you consider the room/speaker complex as an integrated transducer system. However, when it comes to source players and amplifiers, I do think that essentially ALL audible aspects are already covered by the physical measurement methods available today.

Second, it is true that many if not all tube amps exhibit definitive sonic signatures that are both readily measurable physically and clearly audible in well-controlled blind listening tests. The high output impedance of tube amps mentioned above is one of the major reasons for this. In other words, if you define the "ideal amplifier" as the one that does nothing to the input audio signals but faithfully amplifying them, then very few, if any, tube amps can even come close to today's solid-state amps, including fairly cheap SS amps.

However, as others have already pointed out, some people define the ideal amp very differently, and it is true that signal "aberrations" induced by some tube amps are indeed subjectively pleasing to many people. For example, single-ended triode designs tend to add a lot of even-order harmonic distortions -- basically, distortions consisting of the signals exactly one octave above the input sound (2nd order), two octaves above (4th), two octaves and fifth above (6th), three octaves above (8th), and so on... These distortions are MUCH less harmful musically than odd-order harmonic distortions, and sometimes even positively pleasing to people's ears (in contrast, the 5th, 7th order harmonics and above are "out-of-tune" as you know). I fully understand that these clearly audible sonic characters of tube amps add a lot to the enjoyment of the audiophiledom as a hobby.

Third, in my personal opinion, all commercial tube amps in today's market (except for some DIY "kits") are BADLY, GROSSLY overpriced due to this audiophilic tube frenzy of almost religious magnitude. Tube amps today contain essentially ZERO new technologies as compared with the ones made in the '60s -- except for those "frills" such as digitally controlled bias-regulation circuits etc. The manufacturing costs of some parts (including the vacuum tubes themselves) have understandably gone up a little due to the low quantities of production. Yet, as far as I can tell, no tube amp vendors could possibly justify those stratospheric product prices if not for the demands from the relatively small body of quasi-religious, cost-no-object tube fanatics. Of course, the same argument applies to many other absurdly priced "audio jewelries" -- but IMO, tube amps represent a good example of the "super-high-margin" product categories.

Well, Sushi, I agree with you about the even vs. odd ordered harmonics, but as to the rest, I don't figure I know all there is to know about why one amp sounds better than another. As to prices, yes, there are some super expensive tube amps out there, as there are some super expensive pressed sand amps.

Back in the golden-age of tube amps (early to mid 60's) a really nice house cost $40,000, a loaded Chevy Impala with a big V8 could be had for a bit over $3,000, a Buick for about $4,000 and a Cadillac for $5-6,000. So, basically a bit over 10 cents in 1960 dollars, will buy you about what a 2003 dollar will buy you. So, a top of the line tube amp in 1960 might have gone for as much as $500 back then, a perfect example would probably go for thousands of dollars today, used.

There are some super values in SET tube amps. Check out the Antique Sound Labs line. They sound sweet. They don't cost an arm and a leg. Do some research on the net, and you'll find some other good buys on great sounding tube amps.

Thanks, 2x6, to point me to the Antique Sound Labs, a brand I wasn't aware of -- it is refreshing to see that some of their amps are sold for the street price as low as $250/monoblock new. I definitely cannot say those are "overpriced." However, I also see that their SET designs with reputable power tubes (300B, 211, 845, etc), as well as higher-power push-pulls, are mostly priced at multi-grands. I don't know if I would call them a "Hong Kong Bargain."

My friend finally dragged me to a high end audio boutique in Orange County, we kicked back and listened to a $10,000+ AR tube amp and preamp hooked up to a pair of really expensive Thiel speakers, enjoyed a mug of their high quality coffee and some terrific jazz. All I can say is that we both figured that an Antique Sound Labs MG S1 15DT 5 watt per channel SET (KT88 driven), a modified Ah! Njoe Tjoeb tube output CD Player, a pair of M22 like Michaura M55s modified with Jensen paper/oil caps and Caddock resistors, a Vance Dickason Titanic sub sounded at least as good.

BTW, my ASL tubie cost about $700. I swapped stuff which cost me a bit under $400 but for which they credited me for more than $700 for the ASL. I gave them a giant Yamaha 5 channel amp (so big I would've needed a new house which I picked up from a local penny saver ad for about $250) and a Parasound preamp which I picked up on uBid for a bit over $100. They gave me the ASL and some jazz CDs. We all walked away happy.

ASL also has the WAV8 monoblocks for about $100 each. They've received rave reviews, but require a preamp. A pair of these puts out much more wattage than my MG SI 15DT, but watts aren't everything. The MG is smoooooooth, liquid mids, sparkling crystaline highs, punchy rich bass.