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.
Once you try a good tube amp, my bet will be that you will never go back to solid state.
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.
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 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.
Going to a tube preamp is nothing big deal.
But going to a BIG tube amplifier IS a BIG DEAL.
I would love to have a pair of ARC REF600s to run my speakers..
But the power tubes are a big drawback.
If you are buying used, then you may have an issue with the tubes soon enough. Sending them back to ARC for retubing is a must unless you know and trust a local tube guru.
Personally if I have the money to buy the ARC REF600 i WOULD certainly do so for the great experience it could be.

So I say if you can afford the expense of retubing, go for the ARC anyday. It may be a really great experience.
(Or a moneypit)
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.
Matching amps and speakers is important!

Take a look at this link:

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 would pay close attention to ralph's (atmasphere) response as it is probally going to be one of the best ones you will receive.
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’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.
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.
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).
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.

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.
...And many of us clearly find that lower impedance speakers, and ss amps are the better approach for more natural/real sound.
Tube amps are more fun. There I said it.
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.
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 .
I always liked SS sound. The Bel Canto REF1000M's (ss) do a great job with the 802.
Take a look at the new Rogue tube Class D hybrid amps with the B&Ws.
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.
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,
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.
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.
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.
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.
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.
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...
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.
Bifwynne, I would certainly give the ZEROs a try and see how that works out.

If you are using the 8 ohm tap, at the 70-200Hz region the power tubes are loaded at half of what is expected for them. IOW, the output transformer live up to its name- it *transforms* impedance, so if it were to normally load the power tubes at say, 3000 ohms if there were an 8 ohm load on the 8 ohm tap, it would be only 1500 ohms if 4 ohms is on that same tap. The power tubes will thus have higher distortion and lower power as a result.

Now with a lot of output transformers, the 4 ohm tap is not nearly as efficient as the higher impedance taps are. So its no surprise that things go downhill using the 4 ohm tap.

If the speaker can be bi-wired, you could use the ZERO on just the low impedance part of the speaker and run direct on the rest of it.

Got a pair of Zeros that I need to get around to selling. slap @gmail onto my username and shoot me an e-mail if interested.
Currently I have arc ref 250 driving my 802. The arc is replacing a mc302, that I liked, but the ref 250 is way better. I did a comparison between the ref250 and the mc2301, with the arc ref phono 2 and ref5. The all arc system was better, but both amps were able to drive the speakers wonderfully. There were power enough to fill my 36 sq m room. Actually, and don't ask me why, I need less 'watts' with the ref 250 ( to perceive the same volume level) than with the mc302.
What kind of amp you will use should be always seen with the connected
amplifier. You will find a lot of high powered Tube amps which are able to drive
insensitive loads, but they will never get the magic you can get with high
sensitive speakers (in a way this can be said for Transistor amps, too).
Unfortunately it is not so easy to find such speakers because the quality &
design of the X-over is mandatory (Some owners think that - for example -
95dB Wilson speakers are perfect with 18/30W Tube amps, it is a mistake, but
what you don't know you won't hear...). Atma-Sphere will have a good selection
of Speakers which work with their Amps. I would recommend to ask Ralph for a
Recommendation (because his amps are sounding right).
Some say, the magic is in the first Watt .... well, it is not that wrong. I listened to
tube amps matched with high sensitive speakers, they showed a Performance I
never heard with Transistor amps.
Btw. the Ref 600 have no "Tube" Sound, they are pretty straight, but for those
B&W speakers for home theatre the Levinson will do.
Your Wilson example is a good one. Higher load impedance seems more important and beneficial than just looking at a speaker`s sensitivity. It certainly seems the higher the speaker`s ohm-load, the better tube amps(in particular) will sound. Atmasphere`s explanation makes much sense. The sound does become more alive, dynamic and natural.
1) I have heard tube amps that sound harsher than SS amps, vice versa, quite alike, and then of course quite different. I feel the further up in the bucks one goes, the more and more amps begin sounding more alike than they do different. It's almost as if the "hi-fi" world treats Tubes/SS just like they do digital/vinyl...

2) I have noticed that amps, regardless of what they are, can either dig into the speaker well, or they just fail to do so. Even tube amps with say, 90 watts a side vs. my 30 watts a side amps can sound inferior not just sound quality wise but POWER wise...that 90 watt $5K retail tube amp just cannot dig into my speakers like the 30 watter can...same with SS amps...5K-20K SS amps can have just as much trouble, but, the ones that are capable, absolutely flatten my tube amps with respect to breaking open the speaker:)). No getting around that one:)! However, just because they are breaking open the speaker more, does not mean the "quality" is as good. So you are then faced with, am I ok with the power levels I can achieve with the much superior quality OR do I really need the much louder levels with a sacrifice of the quality?

3) I am in the camp that a reference level line stage, a very pure sounding one, can actually do wonders for SS amps...sure, I still find issues with these SS amps vs. my reference tube amps...BUT...those issues are a LOT more subtle and even capable of the compromise. In other words, I can easily live with an SS amp with lesser sound quality (so long as the SS is close enough sound wise) because my preamp gives such a fantastic signal/resolution for that amplifier to enjoy. Some will say the tube magic in a pre ahead of an SS amp is the way to go, and this is indeed a very basic/simple way to go...but my preamp (it's a preamp+dac tied into one unit) has such a clean sound in spite it is a transistor based linestage, that I do not find any point in using a tubed device. I have a tubed pre-dac as well and yes, it adds some flavor, but it's so similar sounding due to the designer's very similar circuitry/design tastes that I don't consider it to be any different in terms of "helping" that SS amp sound more like tubes or whatever. Anyways, point here is that preamp can truly "click" onto a well done SS amp and make all the difference in the world in terms of sacrificing that love for your beloved tube amp, but gaining in that ultimate breaking loose of the speakers.

There's never an easy answer in all of this, but I rank things like this:

Preamp (in my case, pre-dac) and then a "good" SS amp or a "good" tube amp (either/or dependent on your speaker's efficiency or even how loud you need to hear the music).

Lastly, and something I did not discuss is impedance matching..the very best impedance matched system is going to "always" have a head start..matching the system impedance/gain structure goes a long way to get as pure of a signal as tightly locked together as is possible.

Hope this helps others in spite it's a year old thread:))!
There are tubes.
There are transistors.

Both are valid, both can sound good; get both as I did is my philosophy. There is no "vs."

They are what they are.
I can't say one is better than the other. I've used tube for about 5 years and I've loved it, although I miss ss like crazy. That's where I started in the 70's and it carried me all the way until around 2007 when I got my first tubes. When matched properly both are fantastic. I'm missing the ss ease of mind.having both is ideal.
Tube amps are more fun, and more fun is better. There, it's settled.
With my years of experience in this hobby, I have the idea that the best solution comes as either small tube powered amp matching very high efficiency speakers or highly powered SS or class D amps matching modern low efficiency speakers. The trend is class D and low efficiency speakers. High powered tube amp is fast becoming thing of the past as SS amps are sounding very close to tubes.
I still find the Berning zotl amps have the speed, drive, dynamic capability and bass control of the BEST SS amps with the dimension, texture, low level resolution and presence of the best tube amps providing they are ideally matched to the speaker. Really tough to beat that combination of virtues in a tube design. Another big plus is the efficiency of the tubes operating at lower filiment current for longer tube life and less heat in the room. I also agree that there is less place in this hobby for high powered tube amps unless they can somehow find a way to design them to be more efficient.
Zombie thread come back to eat your brains!

You don't have to know anything about the technology of tubes and transistors, or even the sound of them to know that something special is up with tubes. Tubes were declared obsolete about 55 years ago- they have now been around as obsolete technology for longer than they were the only game in town! If they really were obsolete there would be no market forces to cause new tube production facilities to be created but that has happened in the last 15 years or so.

The simple fact of the matter is that the market says there is a good reason for them to be here, decades after they should have been gone forever. We would not have these conversations otherwise!
Tubes are fascinating devices from an electrical engineering perspective but to the less technically educated masses, I think the fact that tubes glow and look cool have something to do with their longevity and cult following. Transistors are boring to look at as are CDs compared to vinyl. And don't even get me started about what file downloads look like. What could be more boring to look at than....nothing? :^)
Nice try Mapman, I'm just guessing that you haven't recently heard or listened to the best attributes that tube contribute to reproduced sound. I could say the same thing about my inexperience with Class D amplifiers. Not all tube amps nor class D "ice" amps are created equally, I've heard a few "ice" amps and while they can offer some of the attributes contributing to good sound they have not to date influenced me in any manner to prefer them over my amplifier. I know that what I am saying has nothing to do with whether they glow or not. First off, I can't even see the tubes in my amp as they are covered by a rather utilitarian perforated cover that doesn't reveal what's inside, they could be solid state, Class D or tube to a casual view. To me it all comes down to what works and sounds most convincing in a given system regardless of tube or SS. Your remarks are a bit more condescending than maybe your intent. After all, our ears should be the final arbitrator in this discussion/debate.

My tubes are hidden in my ARC sp16. They sound really good but do their thing out of site. I'd like to see more of them if possible, but of well....

My mhdt Paradisea has 1 visible tube and a see through plexiglass case that lets the light shine through. Ahhh...

I like to see my tubes glow. ALways have been fascinated by that since just a kid. They look way cool!!!! I can get good sound many ways, but only tubes glow and look cool like tubes.

Call me shallow for liking how tubes glow, but hey, at least that helps make up for my boring looking OHM speakers.

I'd bet that if all tubes were hidden, they would not be as popular. Any takers.
TG, I think the The Map was just having some fun....RIGHT MAPMAN??!!!!!!!!!!!!!! ;-)

I remember an IEEE (I think) paper from many years ago that said, "The transistor is superior to the tube in every regard except one, the amplification of audio". Doesn't mean you can't screw it up and also some speakers will just do better with a ss amp.
"TG, I think the The Map was just having some fun....RIGHT MAPMAN??!!!!!!!!!!!!!!

IF you can't have some fun with cool looking glowy things like tubes, what is there to live for?

Well, I have received a few shocks and burns over the years from gadgets with tubes in them, but I do not blame the tubes for making me want to touch and play around with them. Kinda like women... :-)
Only buy a SS amp if it has VU meters that move...all SS amps should be required to have this, and the fact that they don't is shameful. If you have a tube amp that does not display the tubes, sell it and get one that does. This is really the only way...another idea is to use a SS amp that sounds good (you know.."tube like"), hide it, and place any crappy old tube amp with visable tubes that light up where it can easily be mistaken as the amp driving the speakers, thus having the best of both worlds except for the tube sound, which is also more fun and better for your health, like organic rice.

I like the way you think!

VU meters also glow and are way cool!!! I do miss them also. My squeezebox Touch devices have a VU AND a graphic Equalizer display mode, but I can only use one mode at a time. I need two SBs so I can have all those pretty lights glowing and flashing along with the tube in the DAC, which normally ONLY glows and does not flash. If it flashes, I think that is a bad thing??

Maybe audiophiles truly have evolved and matured to the extent now where glitz, lights and bling does not matter as much anymore as in the past, and Wolf and I are good examples of throwbacks to our more "neanderthal" days?

Nah. The audiophiles have evolved part that is, not the throwbacks part.

Spartan modern gear is largely vendors managing cost and keeping profit levels up I would say. We all would mostly still like to have all the glitz and bling to go along with the good sound.

I blame it all on the AHEE. RaulRuegas, are you listening? Maybe just a little on WAF as well.....
I guess those of us that like and appreciate both tube and solid state electronics must not be welcome here. So Nelson Pass, Dan D'Augustino, Mark levinson and the thousand of other really good electronics designers (read solid state) designs must be like a radio shack piece compared to the simplest tube electronics. Just kidding all. So don't just down my throat. It sometimes appears as if on this site if you aren't 100% in the tube camp you don't exist. Some tube amps just don't do it for me, same for solid state. However, there are some that are absolutely wonderful. Better than the like designed/priced tube/ss amp? nope. different, maybe. Right now, I really like the new Audio Research REF 250 amp. Wow! it is great. But, I'm sure there are equally good solid state amps out there in the same price/quality range. remember, always compare apples to apples.

anyway, enjoy
In all seriousness, the best tube amps I have heard sound pretty much like the best SS amps to me and vice versa. Not sure I have ever heard either sound equally top notch with the same speakers though. Gotta look at the whole picture...