Apos Ray 12AU7 Vacuum Tube

General Information

We're excited to share the launch of a new product we've been working on at Apos: The Apos Ray Vacuum Tubes. These are not your regular tubes–they’re brand new, hand-selected, and tested to meet our rigorous quality standards, unlike the unpredictable quality of the New Old Stock (NOS) tubes commonly available today.

The Apos Ray Experience

Apos Ray Vacuum Tubes promise to take your favorite tracks to a new dimension. Be it the sparkling high-end or the punchy, tight bass, these tubes deliver exceptional audio performance. Vocals become textured and realistic, while hi-hats cut through with clarity. Above all, the impressive depth and separation these tubes offer make them a delight to your ears.

Selection Process

We don't just pick tubes "off the shelf". Each pair is brand new and hand-picked by our sound engineer for optimal gain, conductance, noise, and microphonics performance. The stringent selection process ensures that only about 4% of the tubes make the cut, bringing you an accurate sound staging and channel balance.

Excellence in Every Detail

The Apos Ray’s gold pins are more than just an elegant touch. They improve signal transmission for clear sound, resist oxidation for long-term performance, and ensure secure contact within the socket.

3-month manufacturing defect warranty

With our Apos Warranty covering you for three months against manufacturing defects, your purchase is protected.

Help Shape the Future of Apos Vacuum Tubes

With the launch of our Apos Ray Vacuum Tubes, we embark on an exciting mission to create a comprehensive lineup of tubes that cater to the discerning audiophile.

Right now, we're offering a matched 12AU7 pair, but we have plans to add many more in the future.

We view this as a collaborative journey with the audiophile community and greatly value your feedback and support. Let us know what you'd like to see from us in terms of future tube types and features. Your thoughts and insights will play a key role in shaping our future offerings.

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Meet the Apos Ray Vacuum Tube!

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Latest reviews


Headphoneus Supremus
Best among new production tubes!
Pros: - excellent sound quality
- extremely low noise floor
- great bass extension and quantity
- enchanting mids
- extended but not overly bright treble
- slightly warm tilt
Cons: - price
- unavailable outside of the US
During a recent tour initiated by @Deleeh, I had the unique opportunity to experience the Apos Ray 12AU7 tube, which is a very new entry among new production tubes. It's important to note that I have no affiliations with the manufacturer, ensuring an unbiased review of this product. I didn't even have direct contact with Apos staff, as Deleeh managed everything regarding tour logistics. Luckily I am last in the tour and have had extensive amount of time to test and enjoy them. (roughly a month at this point)

One of the first things that strikes you about this 12AU7 tube is its packaging. Unlike the standard presentation you might expect from 12au7 vacuum tubes, this one comes extraordinarily well packaged. It's clear that the manufacturer aims to deliver a high end product, starting with the unboxing experience.

Front and Back print

Stacked on adapters

Before diving into the sonic qualities, it's worth mentioning the price point. The Apos Ray 12AU7 tube sits at the higher end of the market at 180$ for the matched pair. This might give pause to some potential users, but as we'll explore, the quality and performance may justify the investment for serious audiophiles. At the time of writing this review, the tubes are only available within the US, with no offers in europe.

The setup used for this Review is the well regarded Feliks Envy 300B flagship amplifier. Power tubes used are the Elrog ER300B and in order to use the Apos Ray 12au7, an adapter is required, since the amplifier runs natively with 6SN7 tubes.
Both tube types can be used in the same circuit, since required voltage and amperage are the same, just the socket needs an adapter.
DAC used is the T+A MP2000R and the Source is a Rockna Wavelight Server running Roon with lots of local flac files and Tidal.
Aesthetically some Mini Elrogs paired with big Elrogs


Sound Quality:

When it comes to bass, the 12AU7 tube impresses with its extension and solidity. The bass notes are not just heard; they're felt, providing a robust foundation that's neither overpowering nor underwhelming. It's a delicate balance that this tube manages to achieve, offering a satisfying quantity of bass that complements a wide range of music genres.
As a Basshead I instantly fell in love with the Rays 12au7s presentation of that aspect.

The midrange is where the Ray 12AU7 offers a sweetness that's hard to come by, making vocal tracks particularly enchanting. Instruments have a natural warmth and presence, making each note distinct and full of emotion.

In the High frequencies there's no harshness or sibilance, just smooth, refined highs that extend well, adding sparkle and detail to the music. This silky quality ensures that even after extended listening sessions, listener fatigue is minimal, if present at all.

Compared to all the 6SN7 counterparts that I usually use in my amplifier, the soundstage is more intimate on the Ray 12au7. Instrument placement and separation remains excellent, even though the room size feels smaller than on Linlai E-6SN7 Elite for isntance.

In terms of detail the Ray 12au7 also absolutely delivers. Even finest nuances can be heard very well, which certainly partially depends on the extraordinarily low noise floor, that this tube provides.

Over the full frequency spectrum the Apos Ray 12au7 is mostly neutral with a slight tilt towards the warm side.

In conclusion, the Apos Ray12AU7 offers a compelling auditory experience that justifies its premium packaging and price. Its ability to deliver extended and solid bass, sweet mids, and silky highs makes it a standout choice for those seeking to elevate their audio setup without the hassle of hunting for NOS tubes. Whether you're an audiophile or a music enthusiast looking for quality, the Apos Ray 12AU7 tube deserves your attention.

I personally will add these to my collection after the review tour is over. I'm also looking forward to further tube releases of Apos Audio, they are certainly on my radar now, after this excellent first release.
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Wonderfull and Thank You,🙏🙏🙏🙏🙏🙏.

Thanawit Sagulthang

New Head-Fier
Apos Ray 12au7- Fantastic all-rounder with no major flaw. Will give many cheaper tubes a KNOCKOUT!
Pros: -Warm and Linear Tonality
-Even Presentation
-Excellent Separation
-Extra Sense of space
-Okay Dynamic
-Excellent Timbre
-Low Noise floor
-Immune to EMI
-No major-sound-detriment in any category
Cons: -Poor quality shipment through Amazon
-Extra import fee, depending on country, if purchase through Amazon
Disclaimer: The Apos Ray tubes are purchased with my own money. No one is paying or telling me what to say, all thoughts and opinions are my own.


The Apos Ray tubes were ordered from Apos shop through Amazon. I removed one star because of the damaged packaging. The tubes come in an Apos box which is shipped within a thin plastic sleeve. There is no use of cardboard box or extra bubble wrap to protect the Apos box, as a result through shipment the box got crushed and damaged. Luckily the tubes were intact, however, this is unacceptable as a standard shipping procedure. I order this product from America, and it is shipped to Thailand more protection should be given to product that is shipped internationally. $40 extra is paid for the import fee.

Pic. Damaged Apos ray box (top), Thin plastic cover it is shipped in (bottom).

0. The Context of this Review

0.1 Source Chain

While listening with Ray tubes, I discovered that the sound continues to change up to 20 hours of burn in. Hence, this review is a sound review after 20 hours of use. I listen to music at around 80dB on average. My source chain is Clef power bridge duo (power regulator), Asus laptop (source), Ifi micro idsd black label (digital to analog converter and pre amp), Cayin HA6A(amplifier)(with cage on): Power tubes: KT88 Full Music; Pre tube: Apos Ray; Rectifier tubes 22de4: NOS General Electric [GE], NOS Rca [RCA]. Hifiman Sundara (headphone). Audioquest, Furutech, and Cross Lambda cables.

For a better understanding of the context the reviewer is expressing, this is my opinion on the tonality of the gear I use in this review. Excluding the rectifier tubes in my system I considered my chain to have a relatively neutral tonality. Ifi micro idsd black label dac and preamp (dead neutral)(whisper “I acknowledge this device has a very warm power amplifier section”), Cayin HA6A amplifier (dead neutral), KT88 Full music tube (very slight warm), Hifiman Sundara (neutral, with a slight brightness at around 8kHz), GE tubes (very mid-range forward with bass roll off), RCA tubes (warm, with treble roll off).


Pic. Cayin HA6A with cage on and Hifiman Sundara (left). Cayin HA6A without cage (middle). Ifi micro idsd Black Label (right).

Pic. Kt 88 Full music tube (left). 22de4 rectifier tubes: top General electric, bottom RCA (right).

0.2 Music Taste

I mainly listen to dramatic instrumental music played by multiple instruments (60% Anime OST, 20% Movie and Games OST, 10% J-pop & J-rock, 10% others) Unfortunately there will be no vocal descriptions in this sound review.

The 10 tracks to give you a glimpse of what I listen to [song/album or anime/artist]

1. What is this thing call love/Bloom into you/Michiru Oshima
2. The Ultimate Price/Violet Evergarden: Automemories/Evan Call
3. BLEACH TYBW theme/TV animation bleach the blood warfare ost1/Shiro Sagisu
4. Journey of a Lifetime~ Frieren Main Theme/Frieren beyond the journeys end/Evan Call
5. Smash an enemy/One Punch Man/Makoto Miyazaki
6. Rapid as Wildfires/Genshin Impact/Yu-Peng Chen
7. Andor (Main Title Theme Ep1)/Andor Vol.1/Nicholas Britell
8. Rainy Night in Tallinn/Tenet/Ludwig Goransson
9. Ga1ahad and Scientific Witchery/Miracle Milk/Mili
10. The Theme from “Modern Juzz”/Modern Juzz/Ponta box

0.3 Description and Interpretation

It is important that I describe my experience as accurately as possible hence, I decided to divide the sound section into two parts. The first part talks about the characteristics of the Ray tube that can be easily noticed, not necessarily its stronger traits, but the characteristics that I find obvious and is the first thing that comes to my mind. The second parts talk about characters that may not be as noticeable at first, it does not jump out to scream at you what it is doing, but is important nonetheless. As for the degree to which the relative strength of each category is, I am deliberate with the terms I use and do not exaggerate my lexicon. If I say it is a “tad better” it is just slightly better, if I say the different is “noticeable” it is certainly easy to perceive that difference, if I say it is “night and day” the difference is enormous. With that said let the review begins!

0.4 Comparison

Others 12au7 tubes which will be used for comparison in this sound review.

1. New production JJ Tubes (came with the amplifier) [JJ]

2. New production Full Music $70 (per pair) [FM]

3. NOS Sylvania 6085 $70 (per pair) [Sylvania]

Pic. JJ, FM, Sylvania, and Apos Ray tubes.


In general, Ray tubes have a well-rounded sound, it keeps the instruments impressively well separated, has a slight warm and linear tone with no sibilant to be found, equipped with a classic increasing-space-from-tube plus some extra texture, topped off with great timbre and low noise floor. It received a 5/5 stars for sound.

1. The most noticeable characteristic of this tube

1.1 Warm and Linear Tonality

The first thing I noticed with the Ray was the shifted in tonality. If JJ tubes are considered to be dead neutral, Sylvania and Ray are slightly warm, while FM is warmer. The warm tone gives a relaxing cozy vibe to the music in addition with its good extension on both upper treble and sub bass, a healthy level of excitement is maintained throughout the listening session. Overall, the Ray has a very even frequency response with no apparent peak or dip at any particular frequency. This gives the Ray a smooth sound with no harshness left to be found. For context, I am sensitive to trebles and cannot tolerate bright headphones such as Hifiman Ananda or Hifiman Arya. The Hifiman Sundara that I use can be too bright for me if the source that I pair it with is too cold sounding. While using the Ray, the treble extension has good shimmer and sparkle but is never too bright or fatiguing to listen to. In comparison, I find the FM V-shape sound signature, containing a peak at around 8kHz, to be exhausting to listen to with certain genre. The opposite can be said with Sylvania, in which the frequency is rolled off at both extreme frequencies. The Ray contrasts other tubes as less enjoyable, from the too bright treble of FM to the lack luster sub bass of Sylvania.

1.2 Even Presentation / Excellent Separation / Tube Pairing

Ray tubes has an engaging sound that does capture your attention without ever sounding too forward or forced. It gives an even amount of body to each instrument, in contrast, Sylvania gives the band-leading-instrument more body, more forward (closer to you), and focus presentation than the rest of the band. The disproportionate body that the lead instrument received overshadows the rest of the instrument, hence separation suffers. Ray tubes, however, give an even amount of body to every instrument. When compared against Sylvania, the loudest sound becomes quieter, and the quietest sound becomes louder, resulting in better instrument separation. In fact, the Ray separation pulls a far lead over the second place, Sylvania, and a giant leap over FM and JJ.

For music with a busy passage with multiple instruments playing together, such as that in a symphony, the separation between each instrument can be heard effortlessly on the Ray. It is a joy to follow through different passages of melodic layer with the Ray, whereas, in a busy passage, no amount of attention given deliberately can ever differentiate certain music layers apart when listening with FM or JJ.

The Ray pairs better with tubes which have good focus and clarity such as GE. Unlike Sylvania, which pairs better with tubes that has a smoother and more laid-back presentation such as RCA. Pairing the Ray with the RCA (which has a laid-back presentation with treble roll off but is hazy/fussy/and has lower resolution) can be too much of a good thing. The combination gives extremely smooth fatigue free music, but the lack of resolution does make it sound bland and unengaging.

1.3 Extra Sense of space

Not every tube can give an extra sense of space around each instrument, but great tubes can, and Ray is one of them. Although Ray tubes have more sense of space than any other tubes that is in this comparison, it should be mentioned that “soundstage size” and “sense of space” are not the same thing. JJ and FM tubes have a small soundstage, the width of the stage in which the band is playing is small, while Sylvania and Ray have a larger soundstage. Even though Sylvania and Ray have a similar “soundstage width”, there is more “space” in between each instrument within that soundstage when listening with the Ray. This should be commended as Ray tubes do not achieve this presentation through an addition of excessive amount of treble frequency. If anything, the presentation sounds convincingly natural as if somehow more space is added to the recording. Sylvania sense-of-space, on the other hand, does not sound as large nor as natural. This is because that sense-of-space is created by adding a reverb-like effect to the instruments, hence the music can sometime sound slightly echoey. The sense of space is even more limited with the FM tubes and is nonexistent with the JJ.

2. Other Characteristics

2.1 Velvety Texture

If clean clear solid-state like presentation is what you are after, such as what found in JJ tubes, Ray tubes are not for you. The Ray adds a bit more texture to music to a similar degree to what Sylvania does (both less so than FM). This makes the sound of instruments decay and the material in which they are made of becomes more apparent. For instance, more body from violin can be heard when the bow moves against the string, drums leather fabric texture and its rumble can be heard more easily when it is hit with a stick. The effect is not overly done and does not make the music sound muddy.

2.2 More Than Acceptable Dynamic

The Ray dynamic is second only to the FM tubes, yet it is more than dynamic enough for me to feel whatever emotion the music is conveying. Orchestra do have a somewhat grand presentation with impactful and deep bass while retaining control. Dramatic feeling reaches the listener when there is a passage with big dynamic swing. The listener would never feel that the Ray is inhibiting the dynamic that the amplifier has to offer, but nor does it deliver the most out of the amp. Note that: dynamic is the trait that I value the most in my system hence being “good enough” to me is likely a “great” for others. FM tubes do bring a more grandiose presentation, more weight and impact, particularly at low frequency. The increase in dynamic switching from Ray to FM is very noticeable. If dynamic is the only trait that you are after, the Ray may not be the best tube for you.

2.3 Excellent Timbre

Ray tubes will show the listener what an excellent timbre sounds like. The instruments tone sounds correct, violin sounds like a violin and piano sounds like a piano, and their tonal color stands out. This is apparent particularly for music which uses real instruments. Each tone of the C D E F G notes that is played can be heard effortlessly and the music is filled with life and energy. The music which is highly melodic dependent that is played by real instruments such as violin and pianos will receive the biggest benefits, although other genres such as rock and metal do receive benefit as well. The Sylvania timbre, which I thought was excellent, is surpassed by a smidge by the Ray. While the dull sounding JJ and the metallic timbre FM sound night and day worse than the Ray.

2.4 Low Noise floor

Ray tubes have the lowest noise floor among the four 12au7 tubes. Having the least “hissing” sound in a listening-test in which the amplifier volume is maxed out when no music was being played. Ray tubes are also well protected from external electromagnetic interference, staying dead silent when phone calls are made 1 meter from the tube amplifier with its metal cage on. This is not the case for Sylvania, as it would make an audible winding noise every time a message is received on my mobile phone and makes a loud winding noise when there is a phone call.


Overall, Ray has many strengths from the sound to the user experience. It is a well-rounded tube with no major flaw in any category, while easily surpassing the performance of the other 3 tubes in most categories. The fact that the other tubes in this comparison always have an “if” or a “but” in certain categories proves just how difficult it is to design a well-rounded tube, in which the Ray is. If the Ray characteristic I aforementioned is to your interest, I highly recommend giving the Ray tubes a try. Although this is not a fair comparison, as I do not have a price appropriate or a more expensive tube to compare the Ray to, it does show that you do get more for what you paid for beyond the $70 mark.
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100+ Head-Fier
Apos Ray 12AU7 - A glowing light in the dark!
Pros: affordable 12AU7 tube
new production
balanced sound
Cons: not available outside USA

Disclaimer: The Apos Ray 12AU7 tubes were temporary provided as part of a European loaner tour

The new production Apos Ray 12AU7 tubes come in a very nice compact box with magnetic closure.
I connected them to the xDuoo TA-22 hybrid tube amplifier as soon as I received them (they had already been burned in by a previous reviewer).
After a bit of a warm-up on first listen, it was immediately clear that the sound of the Apos Ray 12AU7 tubes had gained in clarity and refinement compared to the xDuoo's stock tubes. Really a good upgrade for the xDuoo TA-22.


Balance In - Balance Out

The mid-bass has also gained in finesse, while being less bloomy with a slightly reduced quantity. Its really more balanced over all frequencies while still retaining the tubish qualities. This was also the case when using the Apos Ray with the Cayin HA-3A transformer-coupled tube amplifier (standard tubes from JJ Electronic), you give up some of the mid-bass elevation of the stock tubes for a more balanced approach with improved clarity - it's not less engaging, just a different flavor!



Headphones tried on the Apos Ray 12AU7
ZMF Caldera
ZMF Atrium Closed
Meze Liric
Denon AH-D9200
E-MU Teak
Klipsch HP-3
Dan Clark AEON 2 Closed
Kennerton Rögnir
Kennerton Rögnir Dynamic
Fostex TH-909
Audeze LCD-XC 2021

Gear used for comparison
xDuoo TA-22 [tube hybrid amplifier]
Cayin DAC 11 + Cayin HA-3A [Burr Brown DAC with tube output + transformer-coupled tube amplifier]

It is becoming increasingly difficult to find "new" old tubes at reasonable prices and with consistent quality.
With the Apos Ray 12AU7 you get a balanced tube sound at a high level at an affordable price.
I only wish they were also available outside the USA.
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New Head-Fier
I wonder if they make them from scratch by them self or outsourcing to some factory to make them based on their design and specification and then just do selection and matching and sell the outcome as their product?

Buying and importing from US is not that difficult. If they are that good as described let's hope that some tube-specialized retailers add them to their offer and cover the world's need for good 12AU7 :)


Headphoneus Supremus
I wonder if they make them from scratch by them self or outsourcing to some factory to make them based on their design and specification and then just do selection and matching and sell the outcome as their product?

Buying and importing from US is not that difficult. If they are that good as described let's hope that some tube-specialized retailers add them to their offer and cover the world's need for good 12AU7 :)
As far as I know, production is outsourced to a Chinese factory for now.

Importing wouldn't be difficult, but they do not ship outside USA or Canada at all for now.