In this review we take a close look at the newest and 3rd tube amp of the Auris collection.
Disclaimer: Auris Audio is not related to Headfonia in any way. The Nirvana was sent to me to be featured on Headfonia.com and the local dealer uses our sample to feature at shows.
Only in March of this year we reviewed Auris Audio’s top of the line tube amp, the Headonia, here at Headfonia. Last year we covered their HA2-SE tube amp which won the “Best of 2017” award and so our loyal readers will probably already know all about Auris Audio.
Lately Auris has also been touring with the Head-Fi Canjam shows all over the world and the Serbian brand has become very popular in the personal audio market in a very short time. When I covered the HA2-SE back in 2017, Auris wasn’t as well-known yet in the personal audio segment but after our reviews and Auris’ presence at the different shows, everyone seems to know about Auris Audio. That’s a very good thing and of course if you make great products, word travels quickly.
For those of you who aren’t familiar yet with Auris Audio, make sure to check out the intro in our HA2-SE review first. Auris Audio was founded in 2013. Their mission is to fulfill the desires of the most demanding audiophiles and delight both listener’s ears and visual senses. Auris Audio puts tubes first, and how I like it. Now Auris Audio doesn’t only make headphone amplifiers but they have full product line-up with speaker amps, speakers, pre amps, DACs, and even more.
After Auris developed and launched the TOTL reference tube amp, the Headonia, Auris decided it was time to develop another high-end tube amp with a separate power supply and a lot of power. The Nirvana, which product page you can find here, isn’t the new reference amp but instead it is situated between the HA2-SE and Headonia. That means Auris Audio has three full sized desktop headphone amps in their collection now, but knowing the company’s owner, I’m pretty sure it won’t stop with just these models.
“As its name suggests, is designed to take you to the state of absolute blessedness – nirvana”.
With the Nirvana, Auris wanted to make a premium quality amplifier that enables the user to plug in any headphones they like. From the most easy to drive dynamic headphone to the hardest o drive Planar magnetic headphone, and the other way around. The Nirvana is extremely powerful for a headphone amp and with its 6.5W pure class A per channel it’s an absolute beast.
The Nirvana is based on EL34 power tubes in single ended configuration and the driver tube is the ECC82. We have seen the ECC82 before in Auris’ designs, and with the HA2-SE to be more precise. As before the Auris amps always allow you to set the correct impedance for the headphone you’re listening to but this time we can also find VU-meters which show you the real output power given/used. I will get back to these VU-meters in the “Headphone” section later on.
Also “new” is that the Nirvana now has a dedicated external power supply to deliver the best possible constant (no AC) power to the amp section. From what I understand there will be two version of the power supply: a normal one and the one you can see in the pics, with the same look and feel as the amp. The latter of course makes for the prettiest combo but also the most expensive one. There is no impact on sound between these two models.
The Auris Audio Nirvana sells directly from Auris shop for €5.550 Euro and that does make it a high end amp just looking at the price class alone. The Auris amps seem to be getting more expensive over time with the Headonia selling now for €7.500 Euro and the HA2-SE for €2070 Euro. The Auris amps don’t come cheap but in return you get perfect build quality, exquisite design and superb sound in return. Delivery is included in the price but we’ll get back to the price/quality ratio of the Nirvana later in this article.
The Nirvana, just like its siblings, comes in black or in white but unfortunately the black version wasn’t available at this time, so that leaves me with a white Nirvana, the odd one in the collection. The Nirvana comes delivered with a pair of Auris branded gloves, a user manual, the warranty and the full set of stock tubes. Auris does not ship any power cables but I’m pretty sure that audiophiles at this level will want to use their own power chords. You of course do get the specific cable to hook up the power supply to the amp section (only one power cable is needed). The unit weighs an impressive 19kg. In comparison to the previous Auris headphone amps we’ve looked at, the Nirvana doesn’t come with a remote control, but to me that’s perfectly fine.
As said the Auris Audio Nirvana uses double EL34 power tubes and a single ECC82 input tube.
The ECC82 input tube (which equals to a 12AU7, CV4004, CV491 etc) is a miniature nine-pin (B9A base) medium-gain dual triode vacuum tube. The tube is popular in hi-fi vacuum tube audio as a low-noise line amplifier, driver (especially for tone stacks), and phase-inverter in vacuum tube push-pull amplifier circuits. You can learn everything about this tube type on the following two pages:
The more famous and rare ECC82 tubes can set you back quite a lot when you want to buy them NOS (New old Stock). If you’re not really into tubes or don’t know much about these exact tube types, then I really advise you to read up on them if you’re planning to tube roll the Nirvana. Luckily there is a lot of information available on these tube on the www, and you can spend days reading up on reviews, comparisons, prices, etc. I love doing that but for you it might be different. In that case you can just stick to the stock tubes (see later).
The EL34 power is a thermionic valve of the power pentode type. It has an international octal base and is found mainly in the final output stages of audio amplification circuits. It was designed to be suitable as a series regulator by virtue of its high permissible voltage between heater and cathode and other parameters. The American RETMA tube designation number for this tube is 6CA7. The USSR analog is 6P27S (Cyrillic: 6П27C). You can find out all about the EL34 on the following two pages:
Stock tubes & replacements
The Nirvana of course comes with a set of tubes for both tube types.
For the EL34 Auris has selected newly built Electro-Harmonix tubes from Russia. According to EH, the EL34 is the most common power pentode found in British amplifiers such as Marshall, Hiwatt, Laney, and Sound City. The EL34EH defines the classic British rock sound of the 1960’s and 1970’s. The EL34 sells for about. The Electro-Harmonix EL34EH, according to EH again, is extremely musical and predictable with a sound that is rich, smooth, and detailed without being edgy. It is the perfect EL34 for vintage equipment and a sure way to improve the performance of modern equipment. According to the technical journal, Vacuum Tube Valley, “The Electro-Harmonix EL34EH is balanced throughout the entire music spectrum. Bass goes deep and is tight, mids are sweet and well defined, and highs are detailed and extended.” The EH34 officially sells for about$35USD a piece and the balanced set costs a bit more. A quick Google search however shows these can easily be found for €40 a normal pair and €50 for a matched pair.
The ECC82 that came with the Nirvana actually is a new built Tung-Sol branded 12AU7W (6189) tube from Russia. The Tube’s specs can be found here. If you look around a bit you’ll find them for about just over $20 a piece on the web. It is a 12AU7 tube built to match the performance of the military/industrial original GE 6189 tube. The Tung-Sol name and trademark have been acquired by the New Sensor Corporation. This new production Tungsol tube is manufactured at their Xpo-Pul factory (also known as Reflektor) in Saratov, Russia. New Sensor is an American corporation and since taking ownership of this factory has been steadily improving the quality of current production tubes.
Did I really use the stock tubes? That would be a no, and I sourced an NOS set of matched RFT/Siemens EL34 tubes and used the NOS Philips Holland made/branded ECC82/CV491 tube I sourced for the Auris HA2-SE.
The EL34 RFT made Siemens have dimple tops (like the EH) and they were made in Germany (like most of the NOS RFT/Siemen/etc branded tubes) but their plate structure and top getter are different. These tubes sell between $90 and $100 a piece but they’re quite nice and a guaranteed improvement over the more emotionless stock tubes. The most upgrade in sound comes from the Philips Holland made/branded CV491 tube input tube, as you can expect.
Everyone likes a different type of sound and the beauty of having a tube amp like this, is that you can change the sound with a simple tube roll. There are plenty of affordable tubes available for this amp, so if you do get one, make sure to try out some different combinations as they will let you finetune the sound to your liking. And it’s also fun looking for tubes and trying them out. That being said, the Nirvana does sound really good with the stock tubes already, so if you don’t want to get into tubes too much, the stock setup will do just fine.
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