Tubes in the pre-amp are easier to do and maintain, but the biggest difference in sound is, IMHO, found in the amp. I have an all tube system and I have to admit that I could use a good passive or a neutral ss preamp without loosing much but I just couldn't give up the tube amps. If your speakers can handle tubes and you can make the mental adjustment to maintenance of tube amps, thats the best way to go. Hybrids are popular and are nothing more that the consolidation of a tube preamp with a ss amp. There are tube integrated which have, essentially, passive line (pre-amp) sections and tube output's.
The biggest sound difference, tubes vs. SS, will be in the power amp, hands down. Having said that, I do not use tube amps for that very reason: they sound too much like tube amps, and I can't live with that much deviation from neutrality. Tubes are vastly better suited for the impedances seen in electronics, not speakers. This is one of those iron laws of physics that no one can do anything about. The closest I've seen to a real solution to this problem is the Berning ZOTL approach, but that limits your choices quite a bit. In the end, you need to listen for yourself, in your system, with music that you enjoy, and decide. The good thing about tube amps on Audiogon is that you won't lose much resale value if you buy carefully.
If your speakers are moderatly efficient , I prefer all tubes. They add a natural richness and level of realism that many SS components can not approach. Tubes do require a small amount of involvement for biasing , replacing tubes, tube rolling. I think its fun. I reccomend Audio research gear to get you started. Its very reliable and well made. My first ARC piece changed my 30+ years of audiophile experences.The sound is so amazing you will not believe how beautiful the sound can be from tube equiptment is.
They matter the most where the most gain is, which generally is in the preamp (or phono stage, even.). All tube system is the best way to go. reserve SS amps for bass-only use, if at all.
I suggest all tube. I use no transistors anywhere in my signal path.
Generally speaking I think that tubes usually impart their characteristics most in amplifiers, and depending on their load it may or may not be for the best of technological reasons. There may be some particular tube amps that are exceptions. While I haven't heard them myself (I very much would like to) the Walcotts may be such an exception. As to whether this imparted characteristic is "nice" is open to debate.
The best place to use tubes is in the preamp and source, adding that wonderful distortion (gulp, I admit it) we tube-lovers thrive on.
A "really good" solid state amplifier will add very little to the signal that it's been fed. Note the emphasis on "really good". Using a quality solid state amplifier downstream allows the infamous "straight-wire-with-mucho-gain" amplifier to feed the preconditioned signal to your transducers with authority. The amp will not add any obvious sonic signature to the music but will provide controlled/consistent power to your speakers. I realize this may sound somewhat theoretical and maybe even a bit of a stretch to some, but there are many "really good" solid state amplifiers on the market. It works for me, even sober.
So far dealers have only played me all-tube amp/preamps or all solid state amp/preamps. I like the liquid effect of tubes, the etched sound of solid state amps I've heard hasn't really done it for me.
Is that because I'm hearing solid state amps that are not "really good"? What would you consider a "really good" solid state amp? And is the cheapest way to not get that "etching" effect to use mosfet rather than bi-polar transistors? I'm still in college so I have to be creative and work within a budget.
lastwaltz, my guess is that you haven't heard a "really good" ss amp, as (1) there aren't very many, and (2) they are all pretty expensive. My list of "really good" ss amps under $5k and $10k retail is: Ayre V5x ($4500) and Pass X350 ($9000). Perhaps some will object to this brevity, but I don't know of any others that are as good as these two in their price range. If you can find either, listen to it, preferably with a good tube preamp. You have been warned, though: you'll find it hard to go back to budget gear.
I don't want to tempt myself by listening to a 4500 amp...yet. I'm kind of leaning forward to an Dynaco ST-70/Klipsch combination.
Tubes probably matter most in the power amp but a tube preamp can add quite alot of tubeyness. Or, like the Audio Research LS 16 I use just add a little bit of that magic to make everything just right. I personally couldn't have a tube amp as too much smoothness kills the inner detail. I started with a Cary AE 3 preamp which was very rich and liquid but was too much for me. It has some wonderful attributes especially for vocals though but the bass and detail wasn't there for me. The ARC preamp however is just right. I'm driving a Parasound Hca 3500 SS amp which isn't noted for being the most smooth ss amp out there but with the Audio Research pre things are smooth and grainfree, ss nasties are gone. I'd been using a Krell preamp before the Cary and the little Cary was easily more enjoyable to listen to than the Krell. You can have too much ss sound too but you can find a balance you'll like with just a preamp IMO.
I really think the power amp is where tubes matter the most. My experience is more limited to guitar amps, but they certainly are amplifiers.
I own a class A tube preamp made by Matchless, which is quite a great item, btw. I also own a '67 Fender Super Reverb. While the preamp is a great thing to bring to a rehearsal room so I can warm up the inevitable Solid State Roland Jazz Chorus I'll find there, it just can't sound as good as the all-tube Fender.
I find that I get the best tone from any amp (clean tone, that is, which is what you're looking for in an audio setting), by keeping the preamp levels as low as possible in favor of cranking the power amp, at least up to the clipping point. Granted, each component may have a sweet spot where you have to set the gain higher on the pre to get the most out of it, but in general, I'd prefer to hear the sound of the power amp opened up than the pre.
As such, I'd much prefer to have a tube power amp and ss pre, if forced to make the choice, than the other way around.
My system is all tube, as is even the CD player which is the Audio Aero Mark II. The McIntosh 2102 glows well in the dark as does my vintage Fisher receiver. Together they heat my room which is appreciated in the winter.
Oh yeah; sounds great,too.
I'm with Unsound, and Karls for perhaps the same reason. I use to be all tubes, including cdp. Then I was convinced into buying the Pass X amp by an amp builder. These things run so clean, that I found all I needed for tubes was my trusty cdp.
I can hear every nuance of each tube I try, most being objectional.
I happen to like the ss amp crispness. There are a lot of sounds that don't approach life without it.
Reducing tubes to the signal source promotes the valve liquidity, spaciousness, and air, while not suffocating the music as an all tube set up of anything but the greatest.
Anyway, great tubes are having their prices pushed to the stratosphere by demand.
Its a discussion that has gone on for years since the advent of transistor from bell lab's, one a transistor is a current device, a tube is a voltage device, most transistor amps are directly coupled to the reactive speaker load and thus can produce extreem low frequency response because of the nature of the device and no output transformer to saturate at low frequency however a speaker is a reactive load, not a totally resistive which is another complete topic in its self, but in a tube amp in push pull configuration, the even order harmonics are cancelled out by the output transformer and since the transformer has a windings in the secondary it produces a better matching to the speaker load and not getting into audio transformer design and therory the transformer acts as a choke and a capacitor kind of like sponge it is able to asorb large peak current and not totally reflect it back on the tube its self to try and put it simply so the amp produces a soft clipping many other things take place in both type amps and it can be discussed for another 30+ years or so.
Both devices have have their place in audio, I use a transistor amp crossed over at 250 hz down for subs and from
100 hz and above I love tube amps mixing and matching can produce cool results in any system providing the frequency response is suited for the amp used.