Tubes vs Solid State


I have have been listening to music all my life but have only recently started experimenting with different amplifier and/or speakers/component combinations. I have recently moved from Parasound JC 1's to Classe Cam 400 monoblocks which I have both loved (maybe the prior a bit more) and are contemplating another move. I have been very intrigued by tube monoblocks and have the opportunity now to move to ARC ref 600's. I can also get Mark Levinson 33's for about the same cost. I am just uncertain about the Ref 600's as I am worried that I might be disappointed in the tube sound.

Can someone with more experience perhaps help me out here ? I am using the amps as part of a home-theatre setup driving 802 d's and other 800 diamond fronts and rears. I would really appreciate some good advice here.
128x128gfdt
Ralph, how critical is the 4 Ohm factor if impedance drops to 4 Ohms from 70 Hz to 200 Hz; and does get above 6 Ohms from 60 Hz to 500 Hz? I drive my speakers with an ARC tube amp, 130 wpc??? Should I invest in the "Zero" device? FWIW, I've tried using the 4 Ohm output taps on the amp and the sound quality goes down the drain.
There has been the question of why there is 4 ohms. The answer is that it makes it easier to make power with transistor amps.

But making power is not by any stretch the same as making the best sound for a given amp. You can look at the specs of any amplifier made and one thing is made clear over and over- with lower impedances the amp will make more distortion.

There is a device called the ZERO which allows you to drive a 4 ohm load, while the amp is loaded at 16 ohms. Even people with transistor amps and class D have reported that the the system sounds better when using the ZEROs rather than driving directly, even if the amp has no apparent problem driving the lower impedance.

The reason why 4 ohms is problematic is several. For conventional transistors, there is a non-linear capacitance exists as part of the junction of nearly any semiconductor. The capacitance is magnified by increased current through the device. This causes increased odd-ordered harmonics; IOW if you put the amp on a high impedance load, it will have less of these odd orders and so will sound smoother.

Output transformers of conventional tube amps will loose as much as an octave of low frequency bandwidth when driving 4 ohms as opposed to 8 or 16 ohms. The transformer will also be less efficient and heat up more and there will be higher distortion (open loop).

Finally, speaker cables become critical- you should not expect to run any speaker cable over about 2 meters with 4 ohms speakers if you want the best response. In addition, the gauge becomes important, a few hundredths of an ohm can have surprising effects on the damping factor.

Four ohms became more popular when the transistor made its way into hifi. It is a way of possibly getting more power out of the amp. Only a few years earlier when tubes were the only game in town, speaker efficiency was pretty important (which is why there were so many horn systems from the 50s and 60s). Transistor power was cheaper to make, and speaker manufacturers realized that if they made the speakers less efficient, they were a lot cheaper to make too. Four ohms was a way of getting back some of the 'efficiency' but of course what we are really talking about is 'sensitivity'! If you don't know the difference, go back and look at the link I initially posted in this thread.

IOW follow the dollars- its cheaper to make less efficient speakers so four ohms 'helps' with 'drivability'.

But in the world of high end audio there really is no argument for lower impedance, as all amplifiers known do not sound as good on the lower impedances, increased power or not. In high end audio, its about sound quality as opposed to sound pressure, so the additional 3 db you get by doubling power from 8 ohms down to 4 isn't a big deal.

Now there are a lot of software programs for designing speakers that say if you put two drivers in parallel, you double the efficiency (which is part of why you see such loads show up so often). This is incorrect- you double the *sensitivity*. IOW add 3 db but that 3 db comes from the transistor amp, not the speaker!

There is also the myth of 'control' that the amp has over the speaker. Any amplifier will have more control over 2 drivers in series than in parallel, yet you will see many who insist its the other way around. But if you look at it from a damping factor perspective, an amp that drives a 4 ohm load with a 20:1 damping factor will have an 80:1 damping factor on the same drivers in series...
Maybe a hybrid power amp would work well;being able to roll different tubes for personal taste and also have the power required to drive the load the B&w's present;moscode
401hr,402au (moscode has in home auditioning) and there are other manufacturers of hybrids as well.
I have a set of B&W 802Ds. The impedance curve is rediculous, dropping to 3 ohms in mid base. You need high power SS amp to drive these. But if you like the tube sound, there's a good compromise. The Cary SA-500.1 monoblock can drive the 802's with ease and still have that airy top end tube sound. I have a pair of these and they are fantastic, huge bass extension with great mids and highs. I'm using the Cary SLP-05 to drive the amps. But the preamp needs some good NOS sweet or soft tubes since the diamond tweeters are so strong.
For movies plus music I would stay with SS. The big AR 600s would likely be seductive for acoustical tracks but may(??) lack the immediacy of SS on movies and driving rock. As others have stated tubes can be quite a treat but do require maintenance and can create a lot of heat. For your speakers and application SS would be my choice, IMO my 800ds are fantastic with big SS monos with all genres.
As Ralph (I am assuming it was Ralph for Atmasphere) said, it is all in the matching- I have used tube amps since the very early 70's and have used many ARC products during that time. ( I currently use very low powered SET tube amps by Lamm, but while the amp i have is wonderful, it is not suited for all speakers). I tend to like smaller rather than bigger tube amps, in part due to the size, complexity, heat, retubing cost, etc. I'm sure that big ARC amp would be killer in the right application.

As far as tube availability goes, I buy most of my tubes from vendors over the phone/Internet, so location is not a big deal. (I don't even know of a brick and mortar store I could go to, even in NYC, to buy a tube these days).
If you are open to experimentation, and want to play around with tubes, why not experiment with a tube preamp to get started? And you could have some fun 'rolling' tubes and getting to see how different tubes affect the sound. (Just be aware, those little preamp tubes can cost much more than big power tubes, if you are buying 'new old stock' vintage tubes).
Tubes make real magic with electrostatic speakers: Quads, Martin Logans, etc. If you were willing to buy a decent pair of electrostats and a decent tube power amp, you could quickly see what tubes can do and how they differ in sound from SS. Atmasphere's amps and a good pair of electrostats would be killer. (I am currently using horns, but have two pairs of Quads, a 63 and a 57, and those are all marvelous on modest e.g. 60 watts or less tube amps- in fact i have the original Quad amps that match my Quad 57's and with 12 or 14 watts, they are a perfect match).
Today, there are some marvelous solid state amps, at least toward the top of the food chain. So, despite my long history with tube amps and preamps, I'm not advocating a 'tube is better than ss' view; again, it has to do with matching, to the speakers, to the preamp (and the source components) and ultimately, to your ears.
Us the right tool for the job at hand. B&W's work better with ss, some other speakers work better with tubes. Choose your speakers, then choose the appropriate amplification.
Bradluke0,
Your experiences and evolution mirrors mine,there`s no turning back.

Gfdt, You are most likely better off with SS amps given your goals with the current setup/speakers you have.There`s really nothing difficult about tube amplifiers, with the right speakers you`ll probably love them.
Best of L uck,
First of all I want to thank you all for the great feedback. It really answers most of my questions. It seems like in the home-theatre setup I intend to use the amps, and the speakers which I intend to use them with, solid state will make more sense and is probably more practical. If I quickly want to watch a movie it will be frustrating to allow for warm-up time first. In South Africa, where I live, it might also be difficult and expensive to find replacement tubes. I am nevertheless still very much intrigued by tubes and will have to go that route soon. I have a normal two channel system in my bedroom with B&W 804 diamonds. Maybe I should start with a smaller tube amp there ? Perhaps any thoughts on what I can use on them ? Perhaps a ARC of around 100 Watts into 8 ohms ?
The message which I am getting from your responses, and please correct me if I am wrong; Tubes are like a beautiful but difficult woman. The times she brakes your heart make the good times even more special.
Thanks again for the great response to my first posting.
Hi all ! I say try it and see how you like it ,you never know . Building a high efficiency high impedance speaker is tough but apparently getting easier . Mine are 96db and constant 8 ohms . Presently driving them with a 15 wpc tube amp , never heard such dynamics and clarity .I will never go back to SS and low efficiency .
Hi Unsound,
It`s simply what works best for us as individuals. Many would share your viewpoint and many others mine. Fortunately we all can be happy either way.
Regards,
...And many of us clearly find that lower impedance speakers, and ss amps are the better approach for more natural/real sound.
Mechans,I`ve wondered about that very same issue for years,why so many 4 ohm speakers on the market? Having owned higher powered SS amps with lower impedance/effiiency speakers and then moving to lower power tubes with a higher ohm load and efficiency. I clearly find the latter approach better for me(more nautral/real sounding). As Atamasphere pointed out in a different thread reccently, it`s more difficult to build a good higher efficiency-higher impedance speaker.My current speaker is 94db and has a 14 ohm load and it`s fabulous.
Regards,
I use tube amps with B&W 800's. In my experience, the biggest difference in using SS and tubes with these B&W's is in bass control. I went from a pair of Bryston 4BSST's bi-amped to a pair of 150 watt Octave MRE 130's mono amps. The sound from the tubes absolutely trumps any other SS I have heard and many other tube amps, thus far. The bass does not have articulate deep punch with the tubes, however, it has a solid specificity that makes drum, tom toms, and any hardwood sound so real. I would say the pitch with tubes is far more accurate and the punch the SS amps offered is not really missed and more akin to the depth of what a sub offers. I hear the drums with more of a real effect, but not with the absolute deep articulation, like what you would get with a subwoofer, and that is what I did, I added a sub. In many instances, I do not even play music with the sub on, unless I want to absolutely rock and play loud, then musical accuracy goes out the window as I crank up Aerosmith Train Kept a Rolling to ear shattering levels with the dual 15's adding the punch to get the party started.

The most accurate way for you to determine what you will like is to listen. The experiences I have had with tube amps and B&W 800's runs contrary to what a few would say are not a good match. But, how many have others have heard Octave MRE 130's mono tube amps with the Super Black Box driving B&W 800's? I dare say not anyone in the continental US besides me.

Ciao,
Audioquest4life
There are many reasons why a speaker designer might choose to use a low impedance, one of which, as you have alluded to, is that it's easier to get deeper bass response with a lower impedance, (at least with most typical dynamic speakers).
Why are so many speakers built with woofer arrays/types that are 4 ohm or less? Is it that hard to make speakers with high low end impedances? That said, I own JM Focal that have less than 4 Ohm minimum impedance and drive them with 78 wpc Tube Monoblocks and yes they sound great. I wonder though if they would sound even better if they had higher minimum impedances.
I’ve been there and for many years (about 15) I listened exclusively to tubes. 6550, 5881, 300B, EL-84. IT was fun...kind of. There was always the issues of re-tubing and finding decent tubes. It got to the point where I just wanted to listen to music and not live in angst worrying about how the tubes were doing.

I agree with Elizabeth that going to a tube pre-amp is pretty painless, but amplifiers are whole different story especially in the power range you’re looking at.

I’ll also echo Ralph’s advice. There’s a reason B&W was marketed with Krell gear.
I`m a person who generally prefers tube power amplifiers but it all depends on the speaker being driven. I agree with Atmasphere,Unsound and others in this situation.Your speaker design seems to demand SS amps given it`s difficult load characteristics.
I would pay close attention to ralph's (atmasphere) response as it is probally going to be one of the best ones you will receive.
Matching amps and speakers is important!

Take a look at this link:
http://www.atma-sphere.com/Resources/Paradigms_in_Amplifier_Design.php

The B&W 802 is designed to work on an amplifier that can double its power when the load is cut in half. Specifically, it has an 8 ohm midrange and tweeter, but the woofers are in parallel and so are 4 ohms. Not only that, but the woofers are 3 db less efficient than the mid and tweeter. To correct this, its expected that the amplifier will double its power into the lower impedance.

No tube amp can do this and so on this speaker, tube amps will have less punch in the bass. Now if you had a speaker that did not expect that of the amplifier, then you could get more punch out of a tube amp than a transistor amp...

Its all in the match. Of course its my opinion that tubes offer more music much easier than transistors do (I know of one transistor amp that is really musical but it retails for over $100,000...).

Another issue with 4 ohms is that the speaker cable is more critical and also that any amplifier driving 4 ohms (tube or transistor) will not sound as good as it does driving higher impedances. So if you are seeking musicality, you may want to consider replacing the speaker as well.
I use the Rogue M180's with KT 120 tubes to drive Martin Logan Summits (which present a very difficult load to amp) with very good effect. You can retube yourself as there is a built in bias meter.
Post removed 
If you need to stick to the B&W's, stick with SS. In addition to all the reasons stated, tubes will be unstable with the loads the B&W need. I had a similar problem with my B&W's but I then sold them off to get speakers that were tube friendly.
If you can live with the practicality issues of that ARC 600 (ie size, mass, heat generation, tube life, etc) and cost (isn't it about 10x the JC1?), then go for it. For that kind of cash, I would have your dealer install it in your home for a trail listen. Then you can see if you can live with it.

Generally, I have found SS amps to be better for me (and I also own a pair of JC1s driving B&W 803ds) than EQUIVALENT priced tube stuff, this comparison is a whole new ballgame. Generally that is because driving my 803ds with an equvalently priced tube equipment means a lot lower power in the tube amp which results in lower dynamic range and transient punch. Where power is important (particularly with B&Ws and movie sound tracks), solid state is the cost effective winner. The ARC 600 takes the power issue out of the discussion, even if its not an apples to apples comparison.
If those 802 d's and 800 diamonds are the B&W's I think they are, then you're probably going to regret going from ss to tubes.
Once you try a good tube amp, my bet will be that you will never go back to solid state.