Conrad Johnson has three small tubes on the sockets. Replacement is as simple as pulling one and, after replacing damping rings, pushing new one paying attention to orientation. 5 min job. When I was young, we had TV full of small tubes. First one was replaced at about 10 years. I would base decision only on the sound in my system and the reputation of the company. SS (even SMT) can be as unreliable - it depends on design and quality of the parts.
You can listen before 30 minutes, you don't have to wait that long. The warm up time, optimal performance, for tube gear varies depending on manufacturer. Changing out a tube will not void a warranty. It is pull out the old and plug in the new, simple as that. Now on a tube amplifier it may NOT be as simple as that as biasing is required and how biasing is performed varies among manufacturers'. It can be quite simple to a royal pain but this isn't about tube amplifiers.
Tube life? well that depends on the circuit. Conrad Johnson gear about every 2-3 years in my past experience with their older gear. Their newer preamps running 4 hours a day I would venture about the same but it will vary on the quality of the tube used. Chinese tubes don't last in my experience, even some of the premium ones at those premium prices although some sound quite good. The better tubes are from the golden age of tube manufacturer from the 1930's through the 1970's. These would be tubes made in Germany, UK, Holland, Canada and USA. Also some of the Russian tubes are also quite rugged and will last longer. The older the tubes, generally the more expensive they will be. There are many reputable tube vendors to purchase tubes from as well as the manufacturer. A further word about tube preamplifiers, don't worry, be happy. They are as reliable as SS. I have been using tube pre-amplifiers exclusively for the past 30 years and have NEVER had any problem other than replacing tubes and an occasional fuse and I must say they are fun to own. You can try different tubes to suit your tastes but you don't have to.
Good advice and comments given above. The tubes use in preamplifier are typically low signal and often run conservatively, they can last year's if of good quality.I have a Quicksilver preamp that I use in a 2nd system, it's 's 23 years old and hasn't missed a beat since the day I bought it new. You can tailor the sound via trying different tubes. Simple modification like capacitors or better fuses make a difference as well ďue to the simple circuits of most tube preamps. My advice, get one that the builder provides a high quality and robust power supply. Power supplies matter.
Very good advice given above. It really depends on the tube type, the vintage/manufacturer of the tube, and the particular circuit design. When tubes are driven close to their maximum rating, they don't last long, but driven modestly, the same tube might last for an extremely long time. There are people who claim that their tabletop radios are on almost all day and the tubes have never been changed in 60 years or more of operation.
Within a given type, there are some tubes noted for their extremely long life. These are typically vintage tubes. I am certainly counting on these claims as I have invested quite a bit to get Telefunken ECC803S tubes for my phonostage (12AX7-type of tube); these have a reputation for being "lifetime" tubes. I am also running some very expensive 348 and 349 tubes in my amp; the amp is rated for very low output (even for these tube types), so I am hoping that the tubes will last for many years.
A lot depends on the circuit the tubes are run in. I know that some designers run tubes quite hard, like the old Counterpoint gear, and tubes had to be replaced every year.
I would suggest buying a replacement set of tubes to have on hand at all times. Once in a while, switch in the replacement tubes, if the sound improves dramatically, it is time to re-tube.
Excellent comments by the others.
A concern I would have with both of the preamps you mentioned, especially if you are using digital sources, is their very high gain (specified as 20 db for the LD-2, and either 22 or 27 db for the CJ depending on what document is looked at). If you are using a digital source, most of which provide non-adjustable maximum output levels of 2 volts or more, such high gains are very likely (depending on the gain of your power amp and the sensitivity of your speakers) to cause you to have to operate the volume control too close to the bottom of its range.
That is less likely to be an issue with vinyl sources, but depending on cartridge output and phono stage gain it could also be a problem in some cases.
Many other CJ line stages, btw, also have gains in the mid-20s.
Good luck. Regards,
AL makes a good and specific observation, my reply was more general in nature. My original (early version) Coincident Line Stage had 18 db of the gain. My DAC has an output of 3.2 volts and my speakers are 94 dB sensitivity. I had too much gain, couldn't go past 10 o'clock on the volume control. I replaced it with a 10 dB gain version from Coincident and all was well, VC range now is 11-2 o'clock for most recordings. Total system gain has to be taken in to account.
In some respects, it is easier to live with a tube linestage or preamp than a solid state one. If you are someone who turns off your solid state linestage, it actually takes much longer for a solid state linestage to be fully warmed up and sounding its best; most tube gear is pretty much fully warmed up in less than 10 minutes. The big convenience factor with solid state is that you can leave a linestage on all of the time.
In terms of ultimate longevity, in some respects, tube gear has a longer life. It is easy to refurbish and maintain classic tube gear for decades while a lot of solid state gear is MUCH harder to find replacement transistors, ICs and op amps.
For me, the choice would come down to sonic preference and the kind of amp that the linestage/preamp will be driving. If the amp is solid state, I would be more inclined to stick with solid state for the linestage/preamp.
It is easy to refurbish and maintain classic tube gear for decades while a lot of solid state gear is MUCH harder to find replacement transistors, ICs and op amps.Isn't *that* the truth! The hardest part about keeping older solid state gear alive is finding the semiconductors! The irony is that many semiconductors are far more obsolete than most vacuum tubes...
"Would running low freq music, heavy bass techno etc etc through system break in the capacitors at all on preamp? Adding more bass overall???"
A very good question, I really have no idea as to how that might affect the capacitor break in, Al or Ralph might weigh in here. I DO know first hand that teflon capacitors take a while to settle in. NOW getting back to what Charles said about power supplies and how they make a difference, I couldn't agree more and it is something you should also pay particular attention to if you really want that bass to come through naturally and well articulated along with the amp/speaker interface. Power supplies are probably the biggest difference in adding a more effortless, natural and larger presentation of the music without it congealing and sounding too LOUD. They ALSO add to the cost. You might also consider integrating a quality subwoofer as well for your music of choice.
"Musicians love tube amps since tubes are easy to replace. Semiconductors failure is harder to diagnose and usually require professional repair."
Not too sure about that Kijanki. I would think it's more about the fact that the sound can be manipulated to achieve a desired result. At least that's the case with the one's that I've talked to. Plus most of the guys that use tube amps just like the sound, it gives them that "tube thing" that can't be replicated by SS. 2nd order distortions and all that makes tubes, well tubeelicious :)
Audio reproduction and tube guitar amplifiers have completely different objectives with one similarity, the preference for tubes in the circuit, it's simply a matter of taste.
Tubegroover, That’s what I heard from the few of them. Nice distortion (crunch) is another reason. It seems logical to me that tech person in the band (often one of musicians) can easily bring amp back to life by simply replacing a tube, but SS amp would be practically irreparable on the road. Any performing musicians here?
Yes, audio amps and guitars amps are different but ability to fix them easily is always appreciated.
articdeath, don't be so quick to dismiss using a tube preamp just because tubes wear out every few years.
The first time you change the tubes to a different brand/type, you will hear the different sonic possibilities tubes can bring to your system.
I was hooked and now own my 3rd tube pre with a SS amp.
BTW, if you are interested in CJ, there are many highly rated used models in the $2500 range; e.g., CJ Premier 16LS and 17LS. (And I don't think the McCormack LD-2 preamp uses tubes).
Impedance matching between the tube preamp and the SS amp is critical, especially if you are still running those low-impedance mono blocks.
And as Al stated, CJ specs indicate high gain levels.
There are many tube preamps out there with low impedance and low gain.
I've been using MFA tube preamp and mono amps for many years and all components have been extremely reliable. Having tube gear does not increase my "audio nervosa" in any way. Speaker placement is more likely to do that! :)
I have a decent tube tester which will confirm if a tube is indeed bad. Other than that, I trust my ears. Tube rolling can be fun, and for the most part, an economical way to experiment with how one's system can sound.
For me, tubes are appealing on a number of levels. ONE: They glow. TWO: They offer sweet dimensional sound. THREE: Once I "went tubes" there was no going back to SS. Yes, I understand that SS can often offer more "punch" at the low end, but my tastes in music are not particularly oriented to amplified mid or lower bass punch. I've listened to many jazz combos in clubs, with acoustic bass, and not once does that bass sound "punchy." Likewise in concert halls with symphonic orchestras.
If I were more into hard rock/metal, I'd possibly be more inclined to choose SS amps, but I'd still want a tube preamp.
Tube components for me, makes for a more engaging way to participate in high-end audio. I love the history and "organic" quality of those glowing glass bottles.
Of course, many others disagree, and YMMV.
Still considering the Conrad Johnson classic 2 SE.
I THINK THERE IS ONLY 1 Small tube in it???? Help me if I'm wrong.
Would this his be ok for rock/metal, or would bass be too slushy with this preamp?
Will be buying ing the nad 546 CD player. And some Grover Huffman cables for my amp to preamp connections, and possibly a pair for my cd to preamp connection, depends how good Santa is this year
Why do you think the tube would be a pain in the ass? There have been many members commenting on the reliability of tubes and the wonderful sonics.
The only effort on your part is finding the brand of tube which sounds best to you, since you'll eventually want to replace the stock tube with a better one. And tube rolling is fun; dealers and forum members can advise you.
But don't rush into this purchase for these reasons:
I don't see any output impedance specs listed for the Classic 2SE, can you find them?
Plus, Almarg has already alerted you to the high gain of 22 or 27 dB, 9.5 VRMS. You may have to use attenuators to have full range of the volume control.
Please list the input specs of your amp and the sensitivity of your speakers.
Don't make the common mistake of mis-matching components.
As others have said, Tube Pre's tend to go forever, before tubes need replacing. Once you have heard tubes in the Pre or Power amp, there is no going back, as far as I am concerned. It is tempting fate to say this, but I have never had a problem with a Power amp tube going and that has been very infrequently. I have heard they can take out capacitors when they go, never with me. Replacing a tube could'nt be easier to do. To check which tube has gone, simply switch one tube at a time to the other channel, till the problem appears in the other channel and you have your culprit.
I have had a number of Tube Pre amps and I agree with Lowrider, that CJ make some of the best, the 17LS I had for a number of years was one of my favourite components. Unfortunately I need XLR outputs into my ARC Ref 75SE and CJ do'nt do balanced outputs, so I bought a Modwright 36.5 as an ex dem model and it is excellent, as good as the Arc Ref 3, in my opinion and a lot cheaper.
Myself and other geezer guitar amp users (in my case since 1962, but not professionally before 1967) were mostly clueless about preamp tubes and abused the hell out of tube amps with no MOLLYCODDLING. Whatever that means…very rare for a good tube amp to fail, even when abused 6 nights a week for several sets a night…my old Fenders…friggin' bulletproof.
You can't abuse a tube preamp via the input signal :)
I play in a band as well and while I have technical skills, the idea that a semiconductor is going to fail on the road is not a happy thought- that bit of equipment is going to have to be dealt with in a shop, not on the road. OTOH a tube can go and its simply a matter of plugging in a new one.
I play metal and heavier music at home and find that tubes do that extremely well. Just a FWIW- electronics generally speaking does not care what material you put through it- if its properly designed it will be as good for metal as it is for classical.
Tubes wear out because the vacuum degrades and the filaments burn up at higher oxygen levels in the tubes. Since you cannot keep a good vacuum forever, this is inevitable.
Solid state devices can fail as well, but this is more determined by the original design and support circuitry than the devices themselves. I have Tektronix measurement gear (such as amplifiers and O scopes) that were built in the late 60's and early 70's using the earliest solid state transistors that still meet factory performance specs to this day. That is because the power supplies and bypassing components were of military or high commercial specification, and voltage transients from the power line did not get in and destroy those transistors.
While you can perhaps overload a tube circuit without a big issue, overloading a solid state circuit can spell disaster for a semiconductor. Under certain conditions, overload and secondary breakdown in a transistor is measured in microseconds. No fuse can protect a solid state device unless the device was designed to withstand the eternity of time it takes a fuse to blow.
Heat is another killer for solid state devices. Failure lifetimes are exponentially reduced at high operating temperatures. High temperatures enhance conduction mechanisms in SS devices that can lead to avalanche conduction and catastrophic breakdown.
So, if a solid state design is done properly to keep heat down and transients controlled, solid state devices can last for decades. They're lifetime may be dependent on replacement of certain components (like capacitors), which if fail, will take the solid state components with them.
I have had a cj Classic 2SE for a little over two years and it's a great preamp....I love the sound it produces....It replaced a McCormack RLD-1 which was nice, don't get me wrong... The Classic blows it away so it was easy to give up remote volume and switching for something as stripped down as the Classic. Sound quality is paramount so for me it was easy to give up the feature set of the McCormack. I am using it with a pair of Quicksilver Mid Monos and it is a killer combo. Both have been rock solid, except for a tube here and there....My previous amp was a McCormack DNA 125 which is a great amp, no doubt but the Classic/ Quicksilver combo sounds better, just won't play quite as loud but I never push it loud so it's not a problem in my small room.
I didn't realise that the Classic 2SE didn't have a remote. In that case, if you are still interested in a tube preamp that mates very well with a SS amp, check out the new Atma-Sphere UV-1 priced slightly less than the Classic 2SE.
The sound is lush, dynamic with 3D soundstaging. No affiliation, just an owner of this wonderful new preamp. It replaced a Rogue and it's brought my system to a higher level. Google a review.