Single Ended Amp

The function of all the grids is to modify the current flowing between the cathode and anode plate, in one way or another, and the multigrid tubes can produce higher powered amplification, but, unfortunately, more distortion. Triode based tube amplifiers were the first, the simplest, and, in the opinions of many, still the best amplifiers. Their sound is incredibly pure, in part, because they are simple. The finest in this category is called a single ended Pure Class A triode amplifier (see below for description of classes of operation). Usually one output tube is used, and the plate is connected to one wire on the primary winding of an output transformer (the secondary winding of this transformer supplies the speakers), while the other wire of the output transformer primary winding is connected to the power supply. Only a few watts of audio power (7-30 watts) can be obtained from such amplifiers, but the sound is marvelous. However, they don't have much application in home theater, because the sounds in movies often require high power to reproduce them realistically. On the other hand, this type of amplifier would be wonderful to have as part of a separate audio system for listening to music at modest volume levels. You should audition a single ended triode tube amplifier in any case, just so you know what they sound like. Models begin at about $1,000.