Yes, everlasting dilemma - vacuum tubes or transistors for amplification? Looking strictly technically, amps and pre-amps with transistors features superior technical characteristics. It is mainly shown in less harmonic distortion and grater damping factor. About harmonic distortion, with vacuum tubes it is lot less then 1%, which actually is not detectable. Modern loudspeaker design greatly overcomes the problem of lower damping factor of tube amps.
On the other hand, using the latest and the best quality passive and active components in combination with vacuum tubes results in constructions that simply achieves more than superior sound (sonic) characteristics when compared with similar solutions with transistors. Therefore, it is not surprise that the highest places in high-end class of equipment are reserved for vacuum tube amplification. Tubes just need to be heard.
What is the lifetime of vacuum tubes?
Lifetime of vacuum tubes depends of type, manufacturer and operating conditions. Generally, NOS (New Old Stock) tubes will last more than the same of newer fabrication.
Looking at numbers, lifetime of vacuum tubes varies from 1,500 to 10,000 working hours. We (NAT) are expecting, for tubes that are implemented in our units, to last at least 4-5 years assuming average use of the unit.
Why tubes have limited lifetime?
The answer for this question should be founded in the operating principle of the vacuum tubes. Cathode of the tube is covered with thin layer of special material (usually barium based) which contains plenty free electrons which can be emitted when this material is heated. In time, this layer partially looses the ability to emit electrons and tube simply becomes "deaf".
How to recognize that tubes in my device are "deaf" and how to replace them?
As we already mentioned, tubes have limited lifetime. The symptoms that indicate that tube is ready for replacement can be different, and not always so obvious. Mainly, it is sounding. Sound from amplifier becomes muffy, details are lost. In some cases occurrence of noise is possible. If this happens with power amp tubes, then the amp usually cannot provide nominal power, or the sound is greatly distorted.
Technically, tube is not able to conduct enough current to ensure proper operating of the device where it is implemented.
In above cases it is necessary to replace old tubes. Our recommendation is that this tube replacement in your device should be performed by qualified expert. If you choose to do it yourself please contact us for details.
How to choose proper cables for connecting my amplification system?
NAT devices are not projected for use with any particular type of cables (signal or sound). The best rule is to trust your ears. If you are in position to try different cables from different manufactures, choose the one that sound best to you. Of course, it is always good to choose the best possible quality and already proved connections.
Is there a need to turn off the electric devices during the stormy weather?
Stormy weather makes electromagnetic charges that can lead to destruction of some components in some of your equipment. Generally speaking, during stormy weather it is recommended to unplug all fairly sensitive electric devices like audio and video devices, computers etc. And not only to switch them off, but to unplug them from the wall socket.