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


I am looking to change / upgrade my tube amp.  I have a good, all-purpose Primaluna EVO 400.  It employs the EL34's and has a nice sound, especially in the ultralinear mode. Other components:  streaming from Innuos Zenith MKIII to Lampizator Atlantic DAC.  Everything playing through Daedalus floorstanding speakers with a 96-97dB sensitivity. Currently, my office / listening room is on the small side: 12'L x 16'W x 8' H, but I'm building a new listening room on our farm where I will later upgrade some components to fit a larger room.  Now, here are the tube amp options I am looking at:

Audion Silver Night PX25  8 Watts.  Very popular among some, touting a slightly more balanced, dynamic sound over the 300B.

Swissonor 45 SE  or  Tektron TK One 2A3 / 45 i   The 45 is the low wattage (2.5W) but sweet tone alternative. Considered by many to be one of the most musical out there. Of course, its low power makes it more restrictive, only efficient with high-sensitivity speakers and in more small-to-moderately-sized rooms.  It might be great in my current office but would have to work harder in a larger one later.

300B Integrated Amp, Make / Model not yet determined.  8-10 watts.  Of course, the 300B is making a big comeback and has wonderful characteristics, especially in the midrange and especially with certain genres of music such as acoustic, vocals, jazz, etc.  I heard one opinion from someone with a history of work in sound production, "The 300B is great if you just want to listen to a female vocalist with a guitar." One take on it.

Adherents of the PX25 and 45 tend to regard the 300B as a nice-but-limited cousin. I honestly have no experience with any of these three tubes.  I moved from SS to tube with the PrimaLuna, a well-built amp that I have increasingly felt carries some limitations that other tubes--more focused specifically on higher sensitivity speakers--would open up the sound in the lower frequencies and some tone qualities all around.

Any opinions would be welcome.

 

gregjacob

@gregjacob are you looking for an "integrated" amplifier which includes the preamp just like your Prima Luna, or are you looking for just the amplifier? There are much more 300b amplifier offerings than are integrated 300b.

kennyc:

Yes, I was looking for integrated at this stage of the game as it would probably be more within the current budget than separates, cables, etc.  Also, space issues where I have my sound system located.

My goal has been to learn from this system so that a major upgrade in about 2 - 3 years would be sussed out.  We are renovating an old farm in the country. I have a room that I'm renovating to be a dedicated music room, larger than the office where I currently have my system.  In my current room I have limited space with a pair of Daedalus Muse speakers.  They are sweet and demand little and I am not pushing them at all.  I will be upgrading to either a larger set of Daedalus or moving to a pair of Coherent 18's.  Both are reasonably high-sensitivity speakers but might require a different amp system at that time.  I'll have a better budget then as well. 

There is a reason 300 B everything /  anything keeps coming up for sale.

it inherently does not work well in its output application or generally falls way short of the power tube task.

 

perhaps consider as a driver tube but nothing else 

clhs04:  I believe there's some truth in that. I think most sound systems, environments, and demands do not fit the 300B ability.  Perhaps for the 20k+ 300B amps, there is a window to perform better, but not the low-budget systems.

@clhs04 I do not understand the comment that a 300B falls way short of the Power Tube Task. Likely, if they are not in the right "environment", they will fall short. 

Like the OP I too have the Daedalus Muse Speakers and enjoy them with a pair of Wellborne Labs DRD300 amps with both the silver wire and the Black Gate Cap upgrades. They are about 8 watts. 

Presently using a Modwright LS100 preamp with the MC option in play. My Atmasphere Pre also sounds exceptional in this system with the 300B tubes. 

Either Streaming or Vinyl has plenty of oomph . Jazz, Strings , Classical and limited Classic Rock all sound excellent. No I have not listened to Rap or Heavy Metal so no comment in that regards.

There is plenty of power to listen at all levels of volume in a smaller room. My listening room is 11 x 15. 

 

Alternately my office, which is 13 x 17  has a 175 watt Class A/B pushing PROAC Response 3.5 and  a 300B tube would certainly not cut the mustard in that system.