The 300B Triode

300B. The 300B is the most well-known and revered member of the Triode family of tubes. Here we have a Czech made Electro Haronix Gold Grid, a Chinese made GuiGuang, and a Russian “Gold Lion”. Surprisingly, to me anyway, the GuiGuang tube sounded best to me in Alan Eaton’s 300B monos. Making a whopping 6-8 watts of power in single ended, the 300B can meet the needs of most speakers and still have that lit-from-within feeling. This was never a consumer tube, it was developed by Western Electric for long distance telephone and saw service all over America with Ma Bell, with original production into the 1980’s. It’s an expensive tube, NOS Western Electric versions are priced like a pretty good used car in 2020. Even in new production, the 300B is expensive. It can be very good sounding in the right circuit, and has been a happy ending for many an audiophile, although I think the lower power tubes outclass the 300B in most every respect. Those tubes require efficient speakers to really appreciate, and in my opinion the slightly higher power is the one and only real strength of the 300B over a tube like the 45 or the type 10. Tube data for the 300B can be found here.