A good 2A3 amp can give a more detailed and open sound than a 300B, but with less bottom-end warmth, and of course, less power. Most are around 3 or 4 watts. This means that you will achieve about a 98db maximum SPL at 1 meter with your speakers, before exceeding the rated power of the amp.
Alot depends on how loud you like to listen, and how much dynamics is in the music. If the music has about 10db peaks, you can listen at about 88db average. If the music has 20db peaks you only get 78db average. Many people find this quite acceptable, but some would not.
My own system has a 2 watt 45 amp for power, and 100db speakers, and I can get 103db max. I think that this is plenty for me.
Now, on to the good points. A 2A3 based amp, that is made very well, with good quality output transformers, and especially with choke loaded plates, will provide some sound that you may not have experienced before. They can be extremely beautiful sounding amps. Many people do say that the 2A3 exceeds the 300B in midrange clarity and liquidity. Also, many say that the 45 exceeds the 2A3, again, at even lower power.
High quality output transformers such as Tamura, Audio Note, and the like, are needed to reduce the high frequency roll-off associated with SET amps, so make sure that the output transformers are top quality. The speakers should provide 8 ohms minimum impedance for decent damping factor, which will alleviate the "bass bloat" commonly associated with SET amps. Careful matching and selection will greatly reduce these common maladies that afflict SET sound.
I think that your speaker's efficiency is marginal for this use, and may not play at the volumes most like. I would recommend using speakers of 98db efficiency, for a max SPL in the over 100db territory. Lowther or AER speakers are made for this application, have very high efficiency and sound great with SETs. They do not have to be front-loaded horns, to have high efficiency. Both speakers I mentioned are direct radiator types, at near 100db efficiency.
Alot depends on how loud you like to listen, and how much dynamics is in the music. If the music has about 10db peaks, you can listen at about 88db average. If the music has 20db peaks you only get 78db average. Many people find this quite acceptable, but some would not.
My own system has a 2 watt 45 amp for power, and 100db speakers, and I can get 103db max. I think that this is plenty for me.
Now, on to the good points. A 2A3 based amp, that is made very well, with good quality output transformers, and especially with choke loaded plates, will provide some sound that you may not have experienced before. They can be extremely beautiful sounding amps. Many people do say that the 2A3 exceeds the 300B in midrange clarity and liquidity. Also, many say that the 45 exceeds the 2A3, again, at even lower power.
High quality output transformers such as Tamura, Audio Note, and the like, are needed to reduce the high frequency roll-off associated with SET amps, so make sure that the output transformers are top quality. The speakers should provide 8 ohms minimum impedance for decent damping factor, which will alleviate the "bass bloat" commonly associated with SET amps. Careful matching and selection will greatly reduce these common maladies that afflict SET sound.
I think that your speaker's efficiency is marginal for this use, and may not play at the volumes most like. I would recommend using speakers of 98db efficiency, for a max SPL in the over 100db territory. Lowther or AER speakers are made for this application, have very high efficiency and sound great with SETs. They do not have to be front-loaded horns, to have high efficiency. Both speakers I mentioned are direct radiator types, at near 100db efficiency.