Matched Pairs of tubes are special order directly from Emission Labs. Typical delivery is within 2-4 weeks.
the EML 300B Mesh is a wonderful and most amazing tube. The use of this tube requires some care, because it is no plug & play replacement for any 300B. However excellent sound quality is possible with this tube.
Some 300B amplifiers work at a low, quite delicate operating point. Some work at an average operating point, and some others try to get the highest possible output power. Obviously, as the above three methods are all used, each has it's own justification. We do need to understand what that justification is, so what did the designer have in mind when he build this amplifier. With amplifier design, there is always the trade off between best sound, and highest output power. It's not possible to have best sound, and highest output power in one design.
We really need to look at how the amplifier design is presented. When we have a "muscle" type of 300B amplifier, claiming to get so and so many Watt out of a standard 300B tube, it has to be clear, the design compromise here was: power at the cost of sound quality. By the same idea we have to understand amplifiers which can produce medium output power only, and such which produce only low power. (of course a pre amplifier, or a driver stage with 300B is also a low power application)
Important is, that speakers should be balanced with the amplifier.
Meaning, if you have speakers with very high efficiency, it is not ideal to operate those with a "muscle" kind of 300B amplifier. It's high output power is not needed, but at the same time, such an amplifier sounds a bit sterile or dominant at very low power. So to say the triode sound is not really there, because it develops only when there is more output signal on the tube, which characterizes such kind of an amplifier. Such speakers benefit a lot more from a typical low output power 300B amplifier.
However when speaker efficiency is low, any low power type of 300B amplifier would be forced to run at it's maximum. Even though with a low power amplifier, distortion at the same output power is much lower, you may find the volume dissatisfactory if combined with low efficiency speakers. In such a case you would operate the amplifier rather at the end of it's capabilities, and dynamics of the output signal may suffer.
Please understand we build only the tubes, but the EML 300B-Mesh, which we talk about here, is designed to use in 300B amplifiers of low and medium-low output power only. So it can not be used in any 300B amplifiers with very high output power. (For this, consider plain EML 300B or EML 300B-XLS)
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