One of the perpetual discussions audiophiles engage in is tubes vs. solid state. Preamps & amps come both ways and both have their enthusiastic supporters. I like the good things about "tube sound" and I like the good things about solid state equipment. Unfortunately, there is a down-side to each and I really dislike the downsides of tubes & solid state. As a prospective buyer of a preamp or amp you may be struck with uncertainty about what to buy after hearing both sides' arguments. One thing you may notice in tube vs. solid state discussions is that, as a group, tube-guys tend to be more passionate about their tube amps and preamps. They HAVE to be to put up with some of the "cons" of living with tubes. Solid state is a lot easier to live with, but many would argue that the price you pay for the livability is less emotional involvement in the music.
A look at the "high points" of the pro/con arguments for both types of hardware is a good place to start.
"Pro"-Tube arguments: they sound more like music; modern tube equipment is reliable (mostly); the essential midrange can be presented with almost magical "rightness"; highs sound smooth, floaty and pleasantly real; there are factories still producing all the popular tubes so supplies will be around for the foreseeable future; you seem to get more loudness from less watts with tube amps.
Tube -"Con" arguments include: tubes have to be replaced periodically (6 months to 2 years is common for preamps, 1 to 4 years is common for amps) and tubes can be expensive, ranging from $30 or so to retube a line stage preamp with 2 tubes, up to $500 of dollars for more complex tube preamps; amp re-tube pricing runs from perhaps $100 up to $1,000 for top of the line amps; tubes themselves are less reliable than equivalent solid state devices; different tubes make the component sound different, finding "the best" sounding tubes can become a pain and/or obsession; a few designs use obscure or hard to find tubes or very expensive tubes; tube designs are generally measurably "noisier" than comparable solid state designs (though this is not typically audible); some tube designs (amps mostly) leave breakable tubes exposed which may not fit some lifestyles (not a good idea around children for example); tube amps can make a lot of heat in a modest size room; deep bass from tube amps can be bettered by solid state designs; tube amps tend to be more expensive than solid state amps especially if comparing watts to watts; some speakers are difficult loads for some tube amps; if the amp is not "self biasing" (approximately a 50-50 chance) the owner will have to manually bias the tubes and some amps require that you provide your own volt meter to do this, if you aren't technically oriented this can be a challenge
Solid State - "Pro" arguments - low distortion; cool running (unless ultra high power or pure class A); highly reliable; no fussing with replacement tubes; excellent control/performance in the deep bass; very quiet; the best designs can be very musical; good designs can drive virtually any speaker made.
Solid State - "Cons" - many designs are not particularly musical sounding; highs can tend to be too edgy to sound natural in many designs (yes there are exceptions); usually don't do soundstage depth & width as well as tubes; some solid state designs sound "slow" when directly compared to tube designs in the same system/room; most solid state designs never quite achieve the same level of musicality (how enjoyable the music sounds) that good tube designs achieve (there are a few exceptions to this now and more come as time passes)
Both tubes and solid state benefit greatly from careful selection of associated equipment. There are amp-preamp combos in both categories which range from terrible to wonderful. Tube and solid state components both benefit from careful selection of the wires you use to connect them to each other and to the rest of your system.
Weighing the pros and cons isn't an easy job. Each person is likely to reach a decision for different reasons. But most people fail to consider a choice that might just be the BEST answer of all. What about having tubes AND solid state? Not too many high end companies make both kinds of equipment, so a mix-and-match approach might be necessary. That's OK as long as it is done carefully.
How do you mix tubes and solid state? Solid state preamp and tube amp or tube preamp and solid state amp? My personal opinion is that a solid state preamp combined with a tube amp brings the worst of both technologies into sharper focus. You drive a tube amp with a low distortion, wide frequency range audio signal with perfect bass performance and the tube amp will reproduce the (probably) lifeless midrange, make the bass less good that it was when it left the preamp and not be able to "fix" the less than pristine/delicate highs the solid state preamp is likely to make.
That leaves tube preamp and solid state amp combinations. This is where magic and musical happiness just might be waiting for you. There are a couple of "ifs". You really will need to look hard for a tube preamp that minimizes the "tube-cons". And you will have to look equally hard for a solid state amp that is head and shoulders above what is accepted as "normal" sound from solid state amps. I'll admit that lots of solid state amps have no soul. They rob music of the fun and the joy. This tends to be something you don't notice while you are shopping. You get hyped up by the dealer and listen to all the detail and the power in the bass and you forget to keep checking your EMOTIONAL reaction to the music. If you find yourself listening to an amp or preamp and getting all worked up about the detail it reproduces and how much better it sounds than what you are using now, force yourself to chill out and take your EMOTIONAL temperature. Are you hot for the MUSIC or hot for the detail or other technical performance parameter. I promise you that the MUSIC is more important by a factor of 10 or more.
When you combine a tube preamp with a solid state amp, you have an opportunity to combine the best attributes of both designs. Late model tube preamps are better than ever at doing deep bass and extended sweet & natural highs. Newer solid state amps drive even difficult speakers while providing authoritative bass performance. The magical tube midrange, soundstage size, "air" and overall musicality from a great preamp passes directly to a low distortion solid state amp which maintains/retains a great measure of the good tube qualities in its output. This can be a match made in heaven if the preamp and amp are selected correctly.
How do you find a tube - solid state pair that work really well together? Shop, listen, ask, read, and don't pre-judge a component only on someone else's experience. Shop at reputable dealers (see another article I wrote for Soundstage! describing how to find the right kind of dealer - see It's All the Same, Isn't It?). Listen to what dealers have to say, but maintain objectivity. Ask other audiophiles you know about their opinions - but remember, those are just 1 person's opinion. Read high end magazines (see the same previous Soundstage! article). When you read, understand that the reviewer will generally be exposed to a lot more equipment, rooms and setups than average audiophiles. Take the reviewer's opinions with a bit more weight - but maintain objectivity. Remember that even reviewers have prejudices that may or may not match yours. Avoid falling into the reviewer-is-guru trap. They might know more than you about high end audio, but their knowledge may or may not be important to your selection process - depends on how closely the reviewer's goals/likes match yours. Collect information, but don't try to solve the problem until you have some listening experiences under your belt.
Remember that listening experiences in different rooms with different equipment can be quite different from what will happen in your room. Try to get loaners or moneyback return privileges or at least even-money trade-ins for other equipment the dealer sells if you make a bad choice. Eventually a pattern will emerge that will have you favoring the performance of a select few components. When you get that close, your work is done... buy something, take it home and enjoy the music.
Here's an example of how this can be trouble-but-worth-it. My favorite tube preamp - solid state amp combination happens to be the one I own. No surprise probably. But if I tell you that the Audible Illusions Modulus 3 or 3A preamp and OCM-500 amp (or OCM-200) sound fantastic together, you are going to have a heck of a time hearing these 2 together at the same place at the same time. There aren't all that many dealers that carry both brands. Then you need to remember to have the dealer use Kimber KCAG interconnect (or something equal/better) to connect the two. And listen to the amp using a Cardas Hex 5C power cord if possible. Now we are really getting into the small percentages of being able to hear this exact combination anywhere but in my listening room. No, you can't invite yourself over for a listen! (-: This is just 1 example of the difficulties involved in the search process.
Approach this as a long term project. Take your time. Don't make snap decisions. Enjoy the process. That's half the fun of exploring high end audio. The other half is when you finally get your system set up and the music brings a tear to your eye or a smile to your face.
.....The Noisy Audiophile