Tube FAQ - The Common Questions We Get About Tubes

Isn't this ancient technology? Well, yes. The first tubes were developed in the early 1920s, so we're getting on to 100 years now. However, that doesn't mean it isn't effective technology. Transistors and integrated circuits (ICs) are smaller, cheaper, lighter, use less power and cost a few pennies a piece. While they make great switches and alarm clocks, it turns out they make lousy music amplifiers. The Class A Triode vacuum tube is a natural amplifier - it simply wants to be linear over a very wide range of inputs with hardly a fuss. By contrast, transistors and ICs have to be forced into linearity with massive amounts of negative feedback, which as we know, smears the fine details of the audio signal.

Much of the world's finest (and often most expensive) audio gear is still based on tubes because they simply sound better than all the alternatives. Tube amplifiers have "died" 3 or 4 times since 1962, but today there are still hundreds of makers of fine amplifiers using tubes.

How long will they last? Tubes are just like candles. When you light them up you are using them up - so they have a finite life. Fortunately, that life is decently long. In a preamplifier, like the BlueBerry Xtreme, the tubes will last on average about 3 years. A set of replacement tubes at today's price is around $60. If you use your gear 10 hours a week, your tubes might last an entire lifetime!

In Power amplifiers, like our pCAT, the power tubes have a slightly shorter life. Around 5,000 hours of use can be expected, and a pair of power tubes will cost around $100 at today's prices.

Where do you buy them? Well, gone are the days when you could buy a replacement tube at the drug store on Sunday afternoon. But, the Internet has come to the rescue. As of today, there may be as many as 100 online tube vendors and that doesn't even count Ebay, where there might be 5,000 or more auctions for tubes on any given day. In short, if you are reading this web site, and you know what the word "Google" means, all the tubes you could ever want are at your fingertips - literally. Of course, we recommend you buy them from us!

What are NOS tubes, and do I need them?NOS means "New Old Stock." It implies a tube that is new and never been used, but was manufactured a long time ago - like say, 1956. It was intended to imply a brand new item that has sat on a shelf for a long time unopened and unused. The importance of this is that tubes made in the '40s, '50s, and '60s are generally regarded as being superior to tubes manufactured today. They are superior for a host of reasons, but primarily because the companies making tubes in those days were the industrial giants of the era who made most of their money on tubes and thus had the most modern tooling and processes possible.

It's fair to say that all things being equal, NOS tubes are superior to currently made tubes. However, all things are rarely equal. And one of them is that the phrase "NOS," as it is now used out in the marketplace, almost never means a "brand new item that was sitting on a shelf somewhere for the past 50 years." It has come to mean "used vintage tubes that test real good on a tester." Very different meaning! So, while we can appreciate the possibility of NOS tubes sounding better, we are also careful of the pitfalls. Be very cautious when buying "NOS" tubes. A tube that tests "100% Strong" on a tube tester, can be a noisy tube that won't work well in a phono circuit, for example. On the other hand, a nice pair of slightly used 1960 RCA Black Plate 12AT7s in a BlueBerry will bring shivers to your spine.

What's all this about "biasing" tubes? This pertains to the output tubes in your tube power amplifier. It is necessary for the user to adjust the "right amount of idle current" for power output tube(s) such as KT-88s or EL-34s, etc. This is required in some push-pull amplifiers to assure that the "push" half of the signal matches the "pull" half of the signal exactly. The usual procedure on old vintage amplifiers requires attaching a meter somewhere in the circuit, and then adjusting some control(s) using a screwdriver until your meter reads the proscribed voltage or current, depending on what amplifier you have. It is generally done every six months, or when you change tubes, and could be way more of a technical involvement than many users would be comfortable with or equipped to handle. Our answer to that is HOGWASH! Our pCAT Lynx tube amplifier uses computer logic to provide a no-hassles means of biasing your amplifier with no tools, no meters, no special information. Just turn the panel mounted control until you get a "green" light and you have absolute perfect bias every time you play. Takes a few seconds and it will always be "right." In preamplifiers, there is no need to bias any of the tubes.

Can I mix tube and transistor (SS) gear?Yes you can. We have many customers who use our tube preamplifiers with SS power amplifiers. Because the preamp is the closest electronics to the source material (CD or LP or FM), the tube gear "preserves" all the relevant nuance and detail in the signal and even though you are then using an SS power amp, your sound will be more luscious, liquid and spatious than when using an SS preamplifier or receiver.

It is less common to use a SS preamplifier and a tubed power amplifier, but that can be done also. When using a transistor (SS) amplifier with JuicyMusic preamplifiers there is one specification to be aware of, and clear about: input impedance of the power amplifier. If the input impedance is below 10,000 ohms, we suggest our Peach II preamplifier for driving that very low impedance. The Peach II can drive virtually any ampliifer that we are aware of because of the special 'SuperLoZ' drive mode in the Peach. For any impedance value above 10,000 ohms all of our preamplifiers are well suited to match up.

Do tubes require more maintenance than SS?The truthful answer is "a little bit." If you need a system you can put on a shelf, plug it in and walk away for 10 years, tubes are probably not the right thing for you. We don't call it maintenance, but prefer to call it "involvement." Tube gear requires marginally a bit more involvement than a brand new JapanCo 100W Deluxe Receiver. There is the periodic little bias adjustment on power amplifiers (see above), and there is periodic tube replacement. If that level of involvement in your audio system is a hassle, don't buy tube gear!

Clearly, we wouldn't do this if we didn't believe the rewards of tube gear far outweighed the minor added involvement. Having a tubed audio system is like driving that original Lotus Elan - a real genuine sports car, whose benefits need not be explained to the owner of same!

How hot do these tubes get?The preamplifiers like BlueBerry, Merlin or Peach don't get much hotter than an average CD player, and they are no where near as hot as an AppleTV appliance! (That's a seriously hot appliance.) Power amps on the other hand can generate heat equivelent to a 200W flood lamp, so they will require adequate circulating airspace. The preamps can be tucked into any rack or enclosure with no concern at all. The power amps do not have, or require any fans for cooling - just a bit of free airspace above the tubes.

Do these products require a long "break in" period?Very simply, no. We burn-in every unit for 24 or more hours and any breaking in that would occur after that is simply your ears becoming more accustomed to the sound. The units DO however, take about 1 hour to fully come up to the absolute maximum operating temperature. During that first hour from a cold start, you will experience very, very slight changes (improvements!) in sound quality.

Should tube gear be left on 24/7?There was a time we said "yes" to that question if you used your equipment every day. That time was when electric bills were $6.month! Today, we can't in good (green) conscience recommend the 24/7 on time. My current suggestion is to turn on your tube equipment about 30 minutes before you want to listen.

Does this stuff sound like old Dynaco and Fisher Gear?Absolutely not. The old vintage gear was great stuff in its day, and even today sounds pretty good. But, vintage designers had a totally different set of rules to go by than we do today for "high end" gear. Vintage gear was always scrubbed meticulously for lowering the cost of parts. If a 10-cent part could replace a $1 part with no change in "measured performance" or reliability, you can bet the change was made. There was really no consciousness about what today we call the "high-end" marketplace. Those designers were great by any standard, but they were generally hampered by "market realities" of price vs. performance vs. competitors.

The vintage gear often had very skimpy power supplies, and there just weren't all the great sounding capacitors we have available today. There was also far too much reliance on measured performance on the bench versus sonic performance. Modern tube gear sounds more open, clear, and dynamic than their vintage counterparts which often sounded hooded, overly warm, and could have a very dark and woody coloration. By comparison with modern tube gear, vintage tube amplification is generally too sweet, too overblown, too much bloom. Modern designs are fast, resolved, and crisp without ever being edgy. They expand the benefit of tubes without the drawbacks. They are more spacious and neutral (what you really want) sounding. Sometimes the term "transparency" is used to describe this difference, meaning the sound which is presented is closer to the sound that was intended, without the very noticeable coloration. So, if all your listening experience with tubes has been old vintage pieces, you owe it to yourself to hear a modern tube design

Why would you name a product "BlueBerry"?Because we got bored with names like Super Ultimate Platinum Reference 6.0i/XRv.

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