300B, 2A3 experiances wanted


I took the plunge and bought an Elekit 8900 which I plan to assemble later this year when the weather here in the Northeast starts to get too nasty to be outdoors. I have not bought the tubes yet and would greatly appreciate hearing from any of you who have direct experiance with this amp and the tubes it takes. It will be played into, at different times, Klipsch Heresy 1's, homemade open baffles featuring Lii Audio F15 full range speakers with no crossovers and maybe even my KEF LS50s on occasion.

I like detail, texture and tone as well as a sense of space and air. Generally listen to acoustic instruments in the jazz and classical traditions, 80-85 db being plenty loud for me. I'm interested in what you think are the best bang for the buck tubes as well as some that might be on the aspirational side.

My prior tube experiance included a Dynakit ST-35 amp i build last winter and a Decware Zkit SE84 I put together the year before that. I find the Deware strangely enchanting but a bit noisy, and the ST-35 is clean and clear but, perhaps because it is a push-pull design and and not a SET, sometimes not as magical as the SE84. Kind of hoping that the third tube amp, Elekit TU8900,  with the right tubes might be the charm. I might mention that I plan to build it stock initally but might consider investing in alternate caps and output transformers if the vaunted 300B/2a3 lives up to it's legend.

Thanks for sharing your knowledge.

Ag insider logo xs@2xbruce19

Bruce I've heard your amp once, at CAF a few years ago and it sounded nice with 300B tubes. That said I much prefer the 2a3 tube it's much more transparent and linear than the 300B while still maintaining a sense of naturalness to the sound. The really important question is what speakers will you be driving? Because your looking at either 3.5 or 8 watts so they better be very sensitive and easy to drive!

The sonics of the 300B are mostly limited by the power and linearity of the driver section, because it is much harder to drive than the 45 or 2A3.

IF the driver is linear and powerful enough, the 300B has a power and expanse unmatched by anything else, with transparency as good or better than a 2A3. But IF you use a 12AU7, 12AT7, or 6DJ8 driver, the 300B will be murky and congested, and the 2A3 (or 45) will sound better.

Like everything else in audio, it depends. Some power tubes are hard to drive, and the 300B is one of them.

A pentode like the 6C6 is better for driving a 300B than those small triodes. My SET45 amp uses one 6C6 per channel.