300B or 2a3 SET Class A for Heretic Model A?


Wondering which one would be the perfect match/magical integrated? 100db is more than enough to drive almost everything.

Between these: Mastersound Compact 300B, Trafomatic Evolution Two, Robson Acoustic 300B Masterpiece,  WE91E or even Luxman SQ-N150.

Thanks in advance!

superelmar

+1 for Aric Audio

Give Aric Kimball a call, he's a great call even if you don't buy his equipment. He offers 2 different 300B amps, a 2A3 amp, an EL34 "Push Pull" amp, a KT88 "Single Ended", and a pair of KT monoblocks. I own his Motherlode XL preamp, and the EL34 "Push Pull", and they are ridiculously good with high end components.

Ralphs (Atmasphere) tube amps get great reviews (though I've not heard them), and would be a great option for OTL amps. He even suggested that you look at the below Raven monoblocks.....tells me a lot about his honesty.

The Don Sachs/Lynn Olson Raven monoblocks that Ralph suggested, are Don and Lynn's end game amps.....though end game costs $10,000 for each monoblock

It always bothers me when some asks about a lower power tube amp and someone chimes in with, get a higher powered amp. To me if you want a 300b, 2A3 or 45 amp get one. I have all three. I listen to music all day and at good volume and one room is 1400 square feet. These amps are the best, and at the same time there is a culture around them. The people who espouse the more power mantra are not part of that culture and are irrelevant if you really want a low powered tube amp that’s about sweetness and musicality and tactile-ness.

@yaluaka I've tried plenty of SETs over the last 30 years as well as designed and built my own using the 45, 2A3 and 300bs. SETs do not rule the roost in any of the areas you mention above. But there are plenty of PP tube amps that fall short; if you've not been exposed to the right PP amps I can easily see how you came to your conclusion.

Here are some things to consider: The mark of the best systems is they never sound loud even when they are. You may have noticed that your SETs seem to get plenty loud but what is happening is the distortion they make causes them to seem louder than they are (there are sound pressure apps for smartphones that can easily show what is happening). When you have an amplifier with less distortion it will be very natural to use more power and enjoy it.

The distortion of SETs increases linearly as you increase the power level. Above about 20-25% of full power, the higher ordered harmonics start to show up. They appear on transients (where the power is) and because the ear uses higher ordered harmonics to tell how loud a sound is, this causes the transients to sound louder, giving the amp a very 'dynamic' quality.

IOW the dynamics of SETs is really distortion and nothing more- real dynamics come from the music.

Bandwidth is another problem; with greater power its progressively harder to make an output transformer that really has hifi bandwidth. So usually the highs are made right and the bass suffers, since the kind of speaker you need to really take advantage of an SET (likely horns) often don't have deep bass response. So if you really want to experience the music properly you'll need subs and driven by the preamp rather than the amps.

OTOH, there are PP amps that are every bit as involving that don't have  these problems. Consider though that if you really want to compare apples to apples, the PP amp might have to use the same kind of output tubes, perhaps it should also be class A and zero feedback as well, to level the playing field? Usually these things aren't considered when making comparisons. You might also consider what happens if the PP amp makes the same power as the SET; for example if compared to a 2A3, perhaps the PP amps only makes 5 Watts? Again, to level the playing field.

If you work to eliminate these variables you find that SETs really don't have an sonic advantage over a well designed and built PP amp.

Hey Atam,

 

you’re entirely right, I have push pull amps too and love them. But that’s not my point. The 300b/2A3/45/50 tube world is a culture unto itself. And I find that huge fun to be a part of. Not only do they (or I should say, they can) sound great, but it’s a very interesting esoteric part of this hobby that’s great fun to learn about, historically both from hifis inception and more recently with Japanese and other Asian cultural approach’s to this era of equipment design. 

It has been a while, but, I have heard the Atmasphere M 60 and M 30 amps.  I liked the sound a lot--very alive and vivid without being harsh.  If you are looking for extra warmth, they might not be ideal, but, they are still very fun to listen to.  More recently (about three months ago) I got to hear their MA 2 (I believe) amp which is much bigger and it sounded great.  Some SET amps are also very lively and dynamic sounding within their restricted output, but, OTLs do the extreme dynamics too and should certainly be under consideration for a tube-based system.

we are a Mastersound dealer the compact 845 is a remarkable amplifier reliable, dynamic, with enough power to drive more moderately efficient set of loudspeakers 

 

one of the most memorable amplifiers I have ever owned in 40 years of professional system design.

 

Dave and Troy

Audio intellect NJ

Mastersound dealer