2A3 Tube Opinions

Looking to add a pair of 2A3's for my amps that are full/meaty leaning towards the vintage sound.  Currently running EML Solid Plates and love them, but looking for more weight to the sound.  Thanks for any advice.


Most of the nos tubes will have a thicker, denser, sound due to a less extended high end. My RCA's sound nice. Another approach is to reduce grain and glare by upgrading the amp's fuse to a Synergistic Research Black fuse and the wall outlet to a Oyaide R-1 or a SR RED or BLACK. TheOyaide has a darker sound. The SR outlets provide a sense of more music and richer denser harmonics.

David Pritchard

Hi Arthur,
I must admit that I find your system and various amplifiers oh so interesting 😊.  Does your Found Music 2A3 amplifier drive the Tannoys full range? What a sonic  (I assume) contrast to the esteemed Dartzeel amplifier. You must be having a ball. I love the EML XLS 300b in my amplifiers. 
A good source of NOS/used quality 2A3s is Vacuumtubes.com.  They have single plate,dual plates, dua filaments etc.
Engraved base/black glass Ken-Rad 2a3’s with dual flat plates are by far the fattest/fullest sounding 2a3 tube I’ve tried.

I usally run RCA dual/black plates, but the Ken-Rads are a nice change now and then.
I could not find much info on your listed 2a3 amps, but various driver tubes may also give the edge to the fuller sound you are seeking (while still using your current EML tubes).

The only DH/SET amps I’ve owned are the Audion Silver Night 300B and the Bottlehead Paramours (2a3) which are currently listed with my system.

Both are SS rectified, so my only options (aside from rolling the 6922/input tube of the Audion and the 12au7 tubes of my Bottlehead preamp) were rolling the driver tubes.

With The Ken-Rad 2a3’s mentioned in my above post I ended up using thinner sounding European 12at7’s to somewhat balance out the sound of the fat sounding K-R’s.

I also use various different/fuller sounding 12at7 drivers with early Viseaux engraved base 2a3’s as well as with Grey/Black plate RCA’s.

I used to switch preamp tubes as well (12au7’s), but this became too much juggling (for me) so I settled with simply swapping driver tubes to match/mate with various output tubes.

Anyway, this may be a simpler course to pursue while still using your current 2a3’s.
I find that, among the low-powered triodes, the 2a3 is one of the leaner sounding tubes.  It does not deliver either the punch or the weight that most other tubes deliver.  I have run a number of new as well as old stock 2a3s in my Audio Note Kageki, and none really stick out much as far as more weight in the bottom end.  I have run both the meshplate and non-meshplate EMLs, the non-meshplate has a tighter sound overall, and the meshplate delivers a huge soundstage and the sound seems to bloom into a large space (some might say slightly phasey sound), but, but I don't think either could be said to deliver more weight (associated with a more pronounced upper bass) than the other.  

I would hesitate to suggest old monoplates because they are so expensive, but, the ones I heard did sound somewhat warmer.  I just think that the leaner sound is somewhat inherent in the 2a3 character.  You might be better off experimenting with different driver and input tubes.  These tubes make a big difference in the character of tube amps.

Good luck.

Thanks everyone for the input so far.  Want to make sure I'm clear there is no harshness or edginess and the amps aren't lean sounding, it's really a case of wanting a bit more of something than overcoming a deficiency.  Call it audiophile greed...   :-)

A little more on my amps they are a two stage direct coupled design with a separate power supply for each stage. The driver tube is 7A4, power tube is of course 2A3. Rectification is by type 82 and 83 mercury vapor tubes.  Here's a link to a long discussion about them from a few years ago.  http://www.whatsbestforum.com/showthread.php?4279-Found-Music-2A3-Amplifier/

I agree with dekay and larryi in that rolling the input and driver tubes would likely be an  effective tatic. Arthur which amplifier do you listen to more often given your terrific choices?  Do you use the Thoress preamp with all of your  power amplifiers?
I use the Thoress pre with everything.  It's really pretty equally split among amps.  I just got a pair of Sophia Electric 300B amps that are getting some serious air time right now.  Not sure where they rank in the world of 300B amps, but it sounds so good last couple days I hesitate to mess with anything. 
Hello Arthur,
 The Sophia Electric 300b has earned a reputation for excellent sound quality, natural is a word often used. It sounds as though your SET amps are driving the big Tannoys pretty well based on your comments.
Lets see, Thoress 845, Sophia 300b, Found Music 2A3 and  the SS Dartzeel.
No doubt you are enjoying audio bliss!
I've been really impressed with the Sophia.  Since I added the Swarm subs and lightened the load on the SET amps, I really am loving all of them.  I sold the Dartzeel and am contemplating either vintage Mac 225 or something from the EL34 family, as a change of pace.

P.S.  You left out the Line Magnetic, also SET...   :-)
I really might have an issue...
Hi Arthur, 
I didn't mean to exclude the Line Magnetic amplifier.  I was under the impression that you had sold it. You don't have an "issue" just exceptionally  good taste 😊.  Selling the Dartzeel is a bit of a surprise. 
Art, when Jeff Day (Positive Feedback online) reviewed the Sophia 300b SET he was using the same speakers as you.  He was absolutely giddy in his praise of this pairing. So I can understand your enthusiasm. 

Regarding el 34 amplifiers I heard a Jadis this year at Axpona and it was "very" good sounding. I'm partial to SETs  but I could certainly be happy with the Jadis given what I heard.
It was el 34 tubed integrated amplifier (not a dedicated power amplifier). So this likely isn't their top example.   Regardless, I can say unequivocally that the Jadis made music if you know what I mean. 


There are a lot of different 300B amps out there that sound better, to me, than the Sophia, but, decent amps are somewhat costly because they employ quite expensive output transformers.

Among the most common low-powered triode tube types--the 300B, 2a3, and the 45, I personally like the sound of the 45.  The 45 has tighter and more punchy bass than the 300B (by comparison, the 300B tends to be flabby and a bit overblown in the upper bass, lower midrange), and is not as lean sounding as the 2a3 (sort of in the middle between the two others); the downside being it delivers even less power than the 2a3.

It sounds like you are looking for a range of different sounds from your collection of amps.  A pushpull EL34 amp would certainly be a good candidate.  If the chosen amp can run other tubes in that family of tubes, I personally like 6L6 tubes for the sound even though they do not put out as much power.  There are some other rare tube types that sound fantastic in pushpull amps, like the 349, 271 and the extremely rare 252.

Another completely different area to explore are output transformerless amps.  This type of amp tends to be extremely lively and dynamic sounding. 

Hi Larryi,
In general terms I understand that the 45 tube has a tighter or more  controlled bass reproduction than the 300b.  I've also have discovered that there's a spectrum of bass performance across different brands of these tubes. I can confirm this having the opportunity to hear 11 brands of the 300b in my amplifiers. 

Furthermore the bass quality of a 300b SET amplifier varies quite noticeably depending on make and model.  There are a multitude of choices in regards to this genre of amplifiers  (as I am certain that you know this). I've always respected your opinions and listening perspectives.  Concerning the Sophia Electric 300b amplifier I haven't heard it but via word of mouth and reviews it's said to be very good sounding (They offer various levels of this amplifier based on output transformer selection).  It apparently is an exceptional  match it seems with Arthur's Tannoys. As is always the case in these matters YMMV.
... contemplating either vintage Mac 225 or something from the EL34 family, as a change of pace.
If you may be considering a vintage EL34-based amp I doubt that you could do better than a pair of Marantz 2 monoblocks.  Although of course they appear for sale only rarely, and are quite expensive.  I owned a pair during the 1990s, and they handily bested the legendary and considerably more expensive Marantz 9 monoblocks I also owned around the same time (although it's possible that condition might have been a factor in that).

I've never heard a Mac 225, but I suspect it would also be a fine choice.  As you are no doubt aware it is considered by many to be the best sounding amp McIntosh has ever produced.  Perhaps not coincidentally, I believe it was the only consumer-oriented separate (non-integrated) power amp McIntosh produced using the 7591 output tube.

Good luck.  Regards,
-- Al
Thanks Al - I will check out the 2.  And well aware of the 225, looking forward
to hearing it in my room soon, if it's as good as I think it will be, then the 225 will be home.  :-)
I've not tried very many 2A3 tubes in my Welborne Labs Moondogs , but the best sound I got was with the " mesh Plate " Sophia Electric 300B with 2.5 volt filaments that work in any 2A3 amplifier . More of everything compared with either of the NOS I tried or the Shuguang 2A3c . The driver tube has a lot to do with the sound, as do the coupling capacitors . But the latter aren't plug n play .  FWIW
Reviving this thread. I just got two (well three but I dropped one and it was damaged) 2a3 tubes from a swap meet. One is a RCA/Cunningham mono black plate and the other is dual box plate Raytheon. Are these good 2a3's? Is there a place in Los Angeles that will test them for a fee? 
@enobenetto Not sure if he will do it for free but Upscale Audio definitely has the equipment to test those tubes.  

@verdantaudio Thanks a bunch!! I will try them and hopefully they will be cool with. I don't mind paying them a fee (reasonable fee). 
@dekay  @biketech60 @larryi and others...

Your recommendations for 7A4 driver tubes for a 2A3 amp?

It is the exact same amp in this thread by @arthursmuck  [I purchased it from Arthur].

I believe the amp came with Sylvania 7A4s, though the lettering isn't clear. I'm currently running Philcos. Thanks.