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

 

A typical 300B SET with zero negative feedback. Frequency response .The green line represents a simulated 8 ohm speaker.This was a Mastersound but is typical for the breed.Tube selection is unlikely to make much difference.

 

A typical 300B SET with zero negative feedback. Frequency response .The green line represents a simulated 8 ohm speaker.This was a Mastersound but is typical for the breed.Tube selection is unlikely to make much difference.

Technically I understand the point. The last transistor amplifier I owned was a very fine German make called Symphonic Line. To this day I haven’t any doubt that it produces superior FR graphs and probably every test bench measurement one would care to see compared with my 300b SET mono blocks.

Playing field changes to actually listening to music and the 300b amplifier went to where my Symphonic Line couldn’t follow or render. So,of course  it depends on what one is seeking in their audio systems.

Charles
 

Yes you can certainly achieve good sound with a zero negative feedback SET but that will require more than a hint of two wrongs making a right.And some good luck.

Many SS and Class D amps also overdamp rather than underdamp speakers so they produce a dead flat frequency response but also sound dry and flat.

I believe all SETs should be fitted with a variable negative feedback control which will help you to better match them to different speakers.When I owned an Almarro 318B I had it modified to include one of them and it certainly helped .I never liked it with zero negative feedback and the default factory setting had slightly too much for my speakers.

I definitely agree that NFB amplifiers need appropriate matching speakers. If this is achieved then extraordinary sound quality can be the outcome. NFB adjustment is a very reasonable and useful idea.. It would widen the range of speakers deemed suitable for the amplifier.

In my audio system the 300b SET, 101D preamplifier and 6080 tube DAC are all zero NFB and the combination sounds remarkably emotionally engaging and sonically captivating. For sure the speakers are designed from the ground up to be very compatible with zero feedback amplification.

Charles

I'm using the Sophia Mesh 300b (2.5V version).  Didn't see them mentioned.  I think they are a great tube and is underpriced compared to the competition.

I think rectifiers are as important at the output tubes.  For a GZ34 designed amp, you can't beat Mullard or Matsushita (same equipment).  I'm currently using a radio shack that sounds excellent.  Probably cost $2.99 new.

Jerry