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Still, we wanted more and when we first heard an amplifier equipped with AVVT 300Bs, we had an us-too moment. Though prone to oxidation, this tube is special just like its manufacturer. It's its own hobby to search the web on the life and times of designer Alessa Vaic. One of his brain children was the 300B SL where SL stands for Super Linear. On the Tri, this tube was as powerful as the JJ in its capability for producing well controlled and deep bass in combination with a very open and wide midrange. Where the previous tubes lacked control in the highest registers, the SL handles those with verve. This tube has been our favorite for a long time. It never plays favorites with any music and can play as loud as we can stand. Mounted on the Tri, it did all the familiar things. When it comes to authority and vigor, the AVVT is definitely the one.


Later we discovered the KR Audio 300B. This is the one with the standard specifications, not the XLS that provides more power when fed more voltage and amperage. With 107dB loudspeakers, the 6 to 8 watt a standard 300B puts out is more than sufficient. The KRs build quality surpasses the AVVT with gold-plated pins that won't oxidize. We visited KR's Prague factory and witnessed their tube production to be impressed. Now we put the Czech valve on the Japanese Tri and let it settle. Surprisingly, the KR was the least tall of all tubes tested here but not the lightest. The accompanying specifications of 15 watts output for a standard 300B and 32 cathodes that are really 32 sides on the 8 cathode strips are a bit wishful but the sound wasn't. These tubes handled the signal such that the noise in the room was transformed to wonderful music in our heads. Analytical listening became impossible as the music took over. The KR asserts plenty of control over the entire audible range. Is this the ultimate 300B-alike and thus our perfect match according to Eduardo de Lima's theory?

There was only one test left, with the tubes we currently use in our standard system. Those are Western Electrics. How close can you get to the original 1935 tube with these produced by WE on the same machines as then and even with certain original materials? The WE is the most expensive 300B in our stash. With the KR's impression of mistress-with-silk-gloves authority still in mind, the first tones with the WE were a shock. How could a tube so light and delicate when compared to the cast-iron KR produce a sound that outperformed the KR in two short bars? It must be the simplicity of the build that doesn't interfere with an expression of air and involvement. Where 300B-alikes miss bass extension or add it by fortifying their internal construction, the WE simply amplifies the incoming signal and only adds a little 300B sauce. With the WE 300B, the warmth of the woodwinds, the shininess of the brass and the tension of the drum skins come to the fore and form the music.

We only had a small amount of tubes available for this comparison and there are many more on the market such as by EAT, EH, EML, Sophia and TJ. But these tubes formed a valid representation for us, with price tags from $100 to roughly $900 for a (matched) pair. While not cheap, it's certainly cheaper to roll tubes than buying a whole new amplifier. Now that we found the best match for our system in the Western Electric power triode, another project can concern itself with the driver tube...