Best Tube Amp for High Sensitivity Speakers: 45, PX25, or 300B?

Great question - great idea for a thread.

I previously used a vintage (Cary Audio/Dennis Had designed) AES SE-1 300B stereo amp, from the ’90s. It sounded great and I loved it with my 93dB sensitive/efficent/whatever JBL studio monitors.

Then I had a chance to compare it to a pair of Alan Eaton 45 monoblocks, that put out somewhere around 1.5 watts. The Alan Eatons were better - deeper bass, clearer, lovely treble, richer tone, more beautiful sound. Note - this is in my room, with my listening preferences. I typically listen in the near field below 75dB, so I am just using a fraction of a watt. The Alan Eatons are simply coasting.

A couple months ago I also picked up a pair of Altec A7 Magnificents. ~96dB.

I learned about these amps on the Glow in the Dark audio website. I love that website for the photos, the writing, the descriptions of the various amps and tubes.

Also, as I have previously done, I humbling suggest you download a simple app for your smartphone so you can check what volume you normally listen at. I use decibel X-Pro. It was not expensive and works great. I use it frequently. No, it is not the best SPL meter in the world but it will tell you what you need to know.

Personally I think the 45 tube is where it’s at and these simple, simple circuits with minimal parts count and highly efficient speakers.

@gregjacob 

I think you're going to have to try some different options in your system. while i appreciate the opinions of those who have a strong technical understanding, my experience is that things that should not work DO work for me in my system. 

Again, my system, my room, my preferences. 

Rambling thoughts -

All this talk of "not enough power for your speakers" makes me wonder how loud everybody is listening. I mean really, on a day-in and day-out basis. I seldom get louder than 80dB. Sometimes I go louder, but not as a matter of routine. And I listen to all types of music, including hip-hop, rap, dub, jazz, classical, country, vocals, rock.

I'm seldom using much more than a watt. Ok, perhaps sometimes when I'm listening to the original quads that are in my room, or my 2805s. Or if I feel like cranking up Jimi Hendrix's fist album over the Altec A7s. I might be a little over a watt under those circumstances. But really, how loud do you typically listen? And what kind of speakers are you driving? Something with a power-gobbling complex multi-way crossover? 

8 watts is a lot. 15 watts is a lot. 

My preference is for simple circuits with a parts list employing high quality (read: fit for purpose) parts. Yes you can build high power amps with complex circuits and some of them can sound very very good. But then you're in a different place. Maybe listening for different things. That's ok. Totally ok. There's no one right way to listen or one "right" set of listening preferences. Those who prefer low power SETs are not "better", "smarter" or wiser than those who prefer amps capable of arc-welding. Same with those who prefer Quads, whatever their vintage. Or Altecs or any of all the myriad options available out there, or push-pull or solid state or whatever.

But I do think it is important to experience some of these options first hand, in a well matched system that can show the technology to good advantage.