Aum Acoustics 2A3 Amp

The Aum Acoustics
Statement Quality
2A3 Tube Power Amplifier


One of the finest sounding statement quality stereo 2A3 tube amplifiers money can buy . . . available only on a custom build to order basis (but only to a super qualified audiophile!). I don’t make enough money to build this amp so I’m very careful choosing who I will accept an order from.

Please realize, that building this amp takes up about 3 months of my attention and several hundred hours of actual build time. I could get paid more by working at minimum wage. The result I get, however, is so worthwhile that I will continue to offer my expertise on a very selective basis.

I do want my LIO and Harbeth client’s to know that I not only care intensely about creating high audio quality but have gained my knowledge from direct experience where I’ve achieved my goals through my own hands on success – at a very high level.

My own 2A3 amp (paired with my own LDR based volume control solution) is the only other system that I will recommend in addition to the Vinnie Rossi LIO. This 2A3 amp isn’t for everyone, however, and does not allow for playing all genre’s of music. It is specialized in what it does but what it does do is performed at the highest audio level possible. If you want the finest sound quality for small scale music genre’s, this is your “beast”. If you would like to enjoy all music and achieve an extremely stunning audio quality please consider the LIO as a better overall solution.

(17″ wide x 9.5″ deep x 2.25″ high w/o feet)

It takes about three months to build this incredible amplifier and the two slowest items involved are the chrome plating for the top plate and obtaining the Hashimoto transformer set from Hashimoto in Japan. This is definitely not a production item nor will there ever be a lot of them built. Instead, it is a “cost no object” design and my goal is to create the absolute best sounding 2A3 tube amplifier built in the best way that is possible. I’ve accomplished that goal and am willing to sell this unique “one-of-a-kind” statement quality amplifier for actual parts cost plus a very fair and reasonable markup for my labor.

My raw parts cost for this amp is over $5,000. The tube selection that I’ve tuned this amp for costs around $1,200. It is imperative that a pair of Emission Labs 2A3 power tubes is used along with a NOS Mullard GZ32 rectifier tube. The pair of 6SN7 tubes are selected to match each particular audio system depending upon whether you need complete linearity or an emphasis in a particular frequency spectrum area.

My labor cost will be negotiated with a new prospective client and is definitely a serious value when you find out how many hours goes into building this amp. That’s also without consideration of the research and development needed to create the entire amplifier design. I refuse to give my time away as I have in the past and if no one orders this amp, I’m fine with that.

I have one, love it, and know that it provides the absolute best sound quality possible in audio today. I do not believe that there is a higher quality level obtainable. Staying as close to the first watt of power and using a world class high efficiency speakers system results in a truly fulfilling and extremely unique sound quality. However, everything in audio is a trade off and a better purchase value would be that of a fully loaded Vinnie Rossi LIO paired with the Harbeth Super HL5+ speakers. An alternative would be adding the Vinnie Rossi VR120 power amp and moving up to the Harbeth Monitor 40.2 speakers. However, my vote is for the HL5+ combination.

The LIO plays all genres of music extremely well (particularly when paired with Harbeth) whereas this 2A3 amp is very specialized in what it can do and speaker matching is extremely difficult. Nothing can touch it, however, where it shines if you pair it with a high quality full range speaker system like that made by Rethm in India. I used to be a Rethm dealer and absolutely respect what Jacob George at Rethm has accomplished for my kind of high-end tube amp design.

Audiophile Requirements

My additional requirement (before accepting an order) is that the new owner is capable of and will provide a serious and honest review of this amp. I’m looking for a “seasoned” audiophile who already owns a super quality pair of high-efficiency speakers (97db or higher). I’m also looking for someone who knows audio well and is a serious tube amp lover from owning more than one. I want that new client to have owned and listened to other amps to be able to appreciate how good this 2A3 amp sounds in comparison. It does but that will not be obvious without prior tube amp ownership experience and hence my unique requirement.

If I was able to efficiently allocate my time and not waste a single moment, it would take at least 2 full time weeks to build this amplifier and probably well over 100 hours. However, CNC machining, chrome plating, hard coat anodizing, custom painting, parts ordering is a waiting game and it literally takes about 3 months to complete all of the tasks to accumulate the necessary finished parts and to build this amplifier. It’s a hurry and wait game with many hurdles to traverse through.

It takes a huge amount of patience and the labor investment is intense. Also, there is considerable testing that is done once the build is complete and then a proper listening and burn-in process that follows. I cannot imagine any company building this high quality an amplifier and expecting to make a lot of money. It just takes too much time and is the reason this will remain a very exclusive product and one that I’m not hurrying to build. I’m also not willing to give my time away and consequently, this will remain to be a very exclusive project. I have no interest in doing this in any other way.

My original goal was to build what I call an “archival” reference amplifier, one that will be able to endow many generations of people for a long period of time. I’m very serious about this and feel that including this intangible benefit is something that I must do. This amp’s sound quality is so good that I would like many others to be able to appreciate it.

The Hashimoto transformers that I use are able to be used for at least 50 years before needing repair, re-building, or replacement. In a world of “throwaway” short-lived audio gear, this (for me) is a worthwhile goal and one that allows me to endow other people beyond myself. The market for ultimate quality is small. It also is not one where money making and profitability can take the front seat. Instead, money should be the least consideration. Important? Yes, but not the proper way to create this kind of archival vehicle. Money is only required to purchase the proper grade of parts and to pay for (even though not enough) a reasonable amount of time involved. Without your having some “skin in this game” I’m not willing to offer a gift of my time.


There are a number of ingredients that must be present and included to make a 2A3 tube amplifier one of the best reference examples available:



I have voiced this amplifier around a particular set of 5 tubes that in my opinion sound better than other alternatives:

One, rectifier tube – rare New Old Stock (NOS) Mullard GZ32 in red, white, and blue original Mullard box. This tube is the ultimate for this 2A3 amplifier and I will provide one with the purchase of this amp. (Thereafter, I will sell one of these NOS GZ32 tubes for $250 each. I maintain a stash of these rare tubes and will provide the additional $250 NOS GZ32 in the original Mullard red white and blue box)


A 2A3 matched output  tube pair – New Stock, Emission Labs 2A3. I can provide a new matched pair if you desire. I have them in stock. My purchase price is $500 with the purchase of this amplifier. You can also purchase your own for $629 per matched pair (plus PayPal charge plus shipping cost) at


Two, CV181-TII (aka 6SN7) matched input tube pair – New Stock, Pavane CV181-TII ($290 per Grade A pair at Grant Fidelity) – This is the most balanced sounding 6SN7 tube. I own many NOS rare and expensive 6SN7 tubes and the Pavane sounds the absolute best for my Rethm single driver speaker systems. I can help you determine whether these would be best for your system or another choice. Once again, I can provide a new matched pair of Pavane CV181-Tii tubes if you like. I have them in stock.

I also stock rare NOS MELZ 1578 with the holes in the plates. These are some of the best 6SN7 type tubes available anywhere. They are slightly bright with my Rethm speakers and I prefer the CV-181TII. However, if your system can handle the extra high end extension, these would be “killer” tubes. I paid $283 per Amplitrex matched pair and will sell them at the same price to whoever purchases this amp.


Another rare tube that I stock are the NOS Sylvania 6SN7 “Bad Boys”. Once again, the selection of the pair of tubes in your 6SN7 position is really dependent upon the speakers you intend to use. All three of these types that I’m recommending have the best possible sound quality and these are the type of tubes that make this amplifier sing.


You can use other tubes if you desire but please consult with me before trying anything other than what I recommend above!

However, the Mullard GZ32 is the only rectifier tube you should use for this amp and is why I’m including one with your purchase.