Bóng công suất Emission Lab 300B – Phiến lưới

This tube is a direct replacement for the Western Electric E300B as build until 1988. Glass height and diameter are the same.

Sound Character of the EML 300B

It is probably the most asked question, and for this we refer to the one and only genuine 300B, as made until 1988 by Western Electric itself, in the Hawthorne plant, Cicero, USA, and not to the new production USA made 300B.

The 300B tube has less interaction with the speaker system, as smaller tubes like the 45 have. This makes the sound character less dependant on the speakers, and for that same reason more dependant on the tubes itself. We see 300B often used with medium efficiency loudspeakers. Meaning, the tube often needs to work relatively hard, which is indeed what the 300B is designed for.

However, a Single Ended, no-feedback amplifier can not combine highest output power with lowest distortion. The user will often comes into a situation, where relatively high output power, still requires relatively low distortion. Moreover, distortion should increase as little as possible, during the aging process. Add to this, lifetime expectations are high by itself, even though this tube is loaded often quite hard by the amplifier. Though 300B is strong, these are still no easy specifications for a tube in general.

At EML we have contributed to this, by extremely low hum and low distortion of our 300B tubes, over the major part of the lifetime. This is done by our unique filament and grid construction, featuring a real, physical filament Cathode Tap, positioned outside of the grid, but inside the glass bulb. We use not only gold grid wire, but we completely gold Plate the grid, after it is made. The clean, gold Plated surface increases bias stability, and good matching between two tubes stays constant like this over the full lifetime.