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The 300B World

Disclosure:  I am not new to Aric Audio, but I am new to the 300B.

 

I took delivery of my Aric Audio 300B PSET a couple of months ago. Since then, every listening hour has been different than it would have been were I new to both. I want to know who is responsible for what I'm hearing. So, the overriding question every observation is passed through is simply "Was that the 300B or was that the 'Aric Audio Heft'?" Over the years I have purchased a number of different amps and preamps from Aric and have come to identify certain characteristics that can be expected from all of his builds. That's why I keep going back. Examples include the "dead black" background, the solid signal strength delivered by his preamps, the ease with which the soundstage can be mapped, and the raw power resulting from the overbuilt approach he takes in his design work: "The Aric Audio Heft." Knowing what I would get from any Aric Audio amp is instrumental in being able to appreciate the magic of the "show off tube." 

 

I've heard it said that people who go to the 300B never really come back and I've been intrigued by that ever since. It invites critical listening across the broadest spectrum of music one can tolerate. It's here that observations are bagged and tagged, the first being the kind of music I listen to matters much less because I find myself listening differently and hearing so much more. One of my favorites is the leading edge of the lower frequencies and the way every beat reminds me that I'm listening to a 300B. The way I would characterize the sound profile would be to say it's as if the veil has finally been lifted and the distance between the performance and my listening chair closed. You know it immediately even if you can't quite define it yet and it commands your attention.

 

For some reason I'm surprised by how closely the tonal qualities of SET and PSET modes align. Somehow, I thought there would be more of a "sonic cost" for that extra power. I'm still cautious here though because the quad of tubes I'm using for PSET mode are not topflight tubes. So, the final analysis will have to wait until I can level the playing field. In SET mode I'm listening to a pair of Gold Lions, which I consider to be at least among the heavyweights. The question I'm presently grappling with is which tubes come next? I've done my due diligence researching the various offerings and think it will be a quad of Emission Labs XLS 300Bs. Any input around your experience with 300B tubes I would welcome. Yes, I have my wish list that starts with the Western Electrics (which I'm sure I'll own one day) but the guidance I'm seeking here is the step between now and then. What would be a suitable tube to take an already remarkable experience to a whole new level? Conversely, are there tubes that I should simply stay away from? My thanks to all. Happy listening.

128x128pseudonym
calloway
874 posts
 

My SET monoblocks use 300B as the driver tubes. I have used Psvane ACME 300B and the new WE 300 B tubes. the WE tubes are better but you have to let them burn in for about 300 hrs before they reach their best.I use 845 tubes as my output tubes and use Psvane ACME 845s their also

pseudonym's avatar
pseudonym OP
4 posts
 

My thanks to everyone. There's been a lot of material put forth that will be very helpful in my quest.

markusthenaimnut's avatar
markusthenaimnut
371 posts
 

Fun thread. And yeah, it would be great if there was a website where 300B owners could share, obsess and research information on various amps and brands and vintages of tubes.

BTW, Brent Jesse now includes the JJ 300Bs on his website and speaks pretty highly of them.

A comment about the Cary SE-1; yeah, that's a really nice amp. I have one back in my system right now and it sounds good.

I'm not trying to derail this thread, but I'll reiterate a point I've made elsewhere - I think it is essential to know what sound pressure level you are listening at, and by inference, how much power you're using. I have 93dB efficient JBL monitors and ~99dB efficient Altec Magnificent A7s in my system. I listen around 70dB most of the time. I've found that I can get by with 1.5 watts, and there's a pretty audible difference between the 300B and the vintage 45 tube. So I've switched over to Alan Eaton 45 monoblocks. I still think the 300B tube is a wonderful thing. I used to think "nothing could sound better than this". Now I understand why people talk about 2A3s and 45s and so forth. I love simple, low parts-count amplifiers.

atmasphere's avatar
atmasphere
11,803 posts
 

The rectifier tube should be a consideration in 300B SET build.

In a traditional single-ended 300b amp the current draw is constant, from idle to full power. That means the voltage drop across the rectifier is constant too. If you are hearing differences, there can be only 2 causes; the first being that the amp isn't biased class A1 so at higher power levels the current varies (there is a class A2 and A3 operation where grid current is present at full power).

The second reason is you are hearing the difference due different voltage drops across the rectifier tube itself.

One advantage of tube rectifiers is that don't interact with the power transformer to create 'diode noise'. However, solid state rectifiers can be set up properly so the diode noise is properly taken care of; they can be as quiet as a tube rectifier. The nice thing about this is that they don't go downhill over time and hold up better. If this is done correctly it will outshine any tube rectifier. With DHTs you don't need to worry about cathode stripping since there's no cathode coating.

treperry
1 posts
 

"In a traditional single-ended 300b amp the current draw is constant, from idle to full power. "

Ralph, the current draw is constant averaged over one cycle of the lowest frequency present. Otherwise the current is rising and falling with the input signal.

If the last capacitor in the power supply is properly sized the power supply voltage should stay constant even in the presents of changing current draw on the power supply.

The last cap in a power supply filter should be thought of as a bypass cap (like a cathode bypass cap) for the whole circuit.

Tre'

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