What would a 2a3 based amp. bring to the table?

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.

I am interested in this too. I just got some 96dB Omegas and am looking into an 8W 2a3 SET (Antique Sound Labs) which should give me 103dB SPL at my 8 foot listening position (according to the great crystalaudio.com website). I suppose this will be adequate. I have not fully decided with which amp to go with as far as sound so posts here will interest me too. Arthur

Aball, I think that amount of power will be fine with a 96db speaker. They must be using PP or parallel 2A3 to get 8 watts.

Twl pretty much covered it...from my experience, I purchased a pair of 2A3 monoblocks from Wright-Sound last year for use with my DIY speaker project. I hooked these guys up to my Thiel 3.6 speakers (86 db effieciency) expecting to hear...well I didn't know. These guys simply shoved aside the Thiels' efficency and filled the 13x18 room with more than enough volume for small scale classical instrumental and jazz. As a frame of reference: with my ML 20.6 monos and the volume knob on the preamp at 10 o'clock, the 2A3's put out the same SPL at 1 o'clock on the volume knob. I have no doubt when my single driver Lowther is ready the walls will simply shake. The website for George Wright's stuff is www.wright-sound.com\ He has a new 45 based SET that looks interesting.

Gotta agree with Gs5556! I can only tell you what MY experiences are and based on my tastes and system -- BUT --- in my second system (where I listen to mostly jazz, acoustic, vocals and light rock - leaving the big scale stuff at loud volumes for my main system), I went from a pair of 11-12 watt Cary 300SE Signatures [with WE 300Bs] (driving a pair of Silverline SR-15s and an ACI Titan II LE sub) to the 3.5 watt Wright 2A3 monos and could NOT be happier. The Wrights, to my ears and tastes, have better midrange, better bass and do not poop out or congest as I thought they would on the 89-90db, 8 ohm Silverlines except at outrageously loud volumes.

Not to trash Cary at all, but going from a $5000 pair of amps to a $1500 pair and getting beter sound in my system was a no-brainer.

Good luck and have fun!

More thumbs up for Wright Sound! I recently purchased a pair of Wright 2A3 monoblocks and a Wright preamp, along with a pair of Reimer McCullough speakers which are rated at 94 dB efficiency. A friend who has been building speakers for many years told me that, based on the drivers used, these speakers are probably closer to 90 dB efficiency. The Wright amps do a fine job with these speakers, and they make glorious music!

JD

I would call Don Garber at Fi and ask him to build you his 2A3.

Twl: No, I think they are a single triode 2A3 per channel. You can see for yourself at www.divertech.com. Cool stuff.

Aball, I looked at the ASL website, and all their 2A3 amps are about 3.2 watts/channel. The only 8 watt amps they have are 300B. The reason I made my comment about it, is because you can't get 8 watts out of a single 2A3 per channel. 8 watts is normally a single-ended 300B wattage figure. Check it out. They do have 8 watt/channel 300B amps.

You are right. It is a 300B. I keep thinking it is 2A3.

Speaker comparability with 2A3/300B SET is not just depends on the sensitivity of the speakers. Impedance curve of the speakers are probably more important than the sensitivity.
For example, you can use 89dB Merlins VSMs with 2A3 SET amps fine since they are 8ohm nominal with very small impedance dip. In other hand, another speaker with 94dB 8ohm nominal but impedance dips down to/below 4ohm will not work well even with 300B SET amps.

Thanks to you all.