The Audio Gods are tough but fair-Have you had the "Curse of the 300B" ?


These amps can really pull you in to hear the singer. The voice instrument is so spot on it can provide moments of disillusionment. For example, I've always preferred Sam Cooke's Live at the Harlem Square Club over Live at the Coppa.  The former is way more free and pushes the R&B needle.  It's musical and soulful.  On my 300B setup I agree with that but I also can put Live at the Copa on and be drawn in... in so much that I start enjoying that album as much as Harlem Square. My attention gets focused on the music and not that this isn't my favorite Sam Cooke album.  And I start hearing and feeling things in the vocals that weren't present before. It's wonderful in the truest sense. 

The 300B SET also delivers smaller group instrumentals like no other.  Drums in the jazz, acoustic/folk settings are sublime.  You really identify the drum skins. You do this sonically more than viscerally.  It is, however, intoxicating.  

When done right these amps can be captivating.  But the 300B mistress is not without its issues.  

-You have to mate it with more sensitive speakers.  This is huge.  You are no longer looking at the lion's share of state of the art loudspeaker reviews.  No. You are searching for sensitive, efficient speakers because the 300B runs out of gas real quickly. 
-You have few choices in amps, 
-You have few choices in tubes and they get really expensive for the 'premium' makes.
-You are likely listening at below moderate to moderate volumes. 
-You may keep a second system to use outside of 300B time. 

When I go back to push pull, or even solid state, I immediately appreciate the power and increased visceral impact.  My attention, however, gets more easily lost, and while they don't sound "bad", I lose the clear window into pieces of the performance.  Subtle nuances of how the singer's voice has personality arising out of the phrasing and tone of the vocal.  Instruments with the 300B sound more "instrumenty".  I don't consider any of what's lost when switching to push pull to be hyper detail or analytic.  Instead, it's characteristics of the sound that aren't there leaving less of the inherent personality of whatever sound is being reproduced--vocal, instrument, or the room in which the performance is taking place.

And so I've done things with my system to help it when it's in 300B mode and push pull mode.  For 300B, I added an REL subwoofer and a second Sumiko I had laying around.  I use those to load the room and expand low end but increase soundstage and make things sound bigger with few watts.  For the push pull setup, I've got the input source all tube whether digital or vinyl.  

This leaves me with the feeling that the Audio Gods are tough but fair.  It's hard to have it all with SET or PP.  Nonetheless, my mind seems made up that it seems easier to work within the 300B setup to make it better as opposed to the push pull. 

As a total aside, I am not the audiophile sage that many are on this forum or out in the audiophile-wild.  I will say with confidence though that if you love hifi you owe it to yourself to spend a month with a SET amp coupled with efficient speakers. 
128x128jbhiller
Hi Mark, In my opinion Yes it would. However this depends on how loud you listen and what type of music you listen to. For jazz, acoustical or any analog music you will achieve healthy volume levels. If on the other hand you listen to bass heavy reggae/ska at loud volume levels and like to pressurize the room with bass- then the 300B will start to run out of steam. I listen to all types of music- including what's mentioned above. With my 97 db speakers the 300B has plenty or current and headroom to achieve very loud levels but I am able to make them clip if I am pushing heavy rock music loudly. In that case, I really like my KT150 single ended or perhaps my EL34 push pull amplifier. However for all music- the 300B single ended sounds better when driven within its power limitations. I hope this helps, Aric
Aric,
Yes, thanks. Those comments are helpful. I'm preparing to move, and in my new listening room I should have room for two systems (since my wife objects to having the rather large JBLs in the living room).  The write-up above and all the comments are very compelling.
Mark/Markus
I have a $120,000 system in a dedicated listening room and it is amazing. 
My second system, in my living room, cost $20,000 and is comprised of a Cary 300 SEI integrated 300 B tube amp with Wilson Benesch Arc Monitors and an REL S/3  Subwoofer. I'm using a Prima Luna tube CD Player and speaker cables and interconnects are Nordost. I can honestly say that the 300B set up is every bit as enjoyable as the big system which cost 6 times more money. Both systems provide a completely different listening concept but the 300 B outfit is so sweet that I could live with it alone if I could not afford both systems! I have been buying and selling stereo equipment for 45 years and the 300 B is very special to say the least.
Question: would 300b amplifiers work with my ~93dB efficient JBL 4430 studio monitors? Or do I need something more efficient than that?
Unless you are playing the speakers nearfield you either will need more power or more efficient speakers.
Again, an SET is best used when the maximum volume attained does not used more than about 20-25% of full power. Otherwise the amplifier starts making more higher ordered harmonics. If you've ever wondered why SETs are known for being so much more 'dynamic' than their low power would suggest, this is why: Those higher ordered harmonics are used by the ear to sense sound pressure and since music has a great deal of transients, the loudness cues (distortion harmonics) initially show up on the transients as you turn up the volume. This sounds to the ear is if its more dynamic but in reality its just distortion. Once you are aware of this fact, its also easier to hear that such is the case, so I may have ruinied it for you if this is how you use your SET.
Own very efficient speakers, 94db+ and be prepared to listen at a lower volume. This is how I prefer to listen, and brings me as close as anything to audio-nirvana.