AYON Epsilon KT150 P180w/T100w class-A Monoblock power amps

NZ$ 34,995.01 pr (incl. GST)
Ayon Audio

"The Bugatti of Audio" - TAS: The Absolute Sound magazine


AXPONA 2018 Show Winner – Positive Feedback Editors Choice
“Audio Oasis” Award!

"Best Sound” Cost No Object LA Audio Show 2017 – The Show Newport 2016 - Robert Harley & Neal Gader
The Absolute Sound Magazine Award

EPSILON MONOBLOCKS: Single-Ended class A Triode Amplification (with real-world power and control to spare)

Ayon's state-of-the art triode vacuum tube amplifiers provide music lovers worldwide with an authentic listening experience in their home environments. They offer abundant power resources unavailable from conventional designs while fully maintaining and expanding the traditional qualities of the single ended topology.

"HXOS" (Greece) 5-star award

"The Epsilon Monoblock immediately makes clear its wider power bandwidth with more speed, top-end air, detailed resolution and more articulate combined with an impactful bass. It has also a wonderful ability to unravel complex musical threads with grain less purity and surprising musical dynamics. This true balanced monoblock provides perhaps the finest  KT88/KT150 design performance available anywhere near its price".

"A Germany reviewer that uses Ayon Audio's Epsilon mono amplifiers for quite some time. He use them in both his mastering work while preparing vinyl re-issues and for reviewing purposes. His amplifiers use eight KT150 tubes each to produce sound. Attendees of the Audio Show in Warsaw (Poland) could find that out for themselves listening to how well these amps handled the mighty Dynaudio Platinum Evidence loudspeakers".

Research and development of our triode amplifiers is conducted by a team of renowned experts at our high end manufacturing facility in Austria. Absolute tonal neutrality, outstanding dynamics and a so far unknown level of resolution are trademarks of our amplifiers, complemented by an explosively fast and uncoloured bass and high power triode performance.

Their sound staging and ambient retrieval equals the finesse of the legendary low power triode designs while leaving behind their disadvantages of high distortion, coloration and limited dynamic reserves. Advanced zero feedback class A circuitry and cutting edge output transformer design make Ayon triode amplifiers recreate music with irresistible magic and authenticity.





Full-featured true balanced vacuum tube mono power amplifier
Switchable between pentode and triode mode
Ideal also for more difficult loudspeaker loads

Vacuum Tubes
The choice of signal and power tubes have a significant influence on the sound and hence on the inspiration and joy of listening. This is not only the decision between good and bad tubes but finally the interaction of the different types of tubes and their combination that are used in the various Ayon amplifiers.

Signal Path
We believe that the simplest circuits work best together with the shortest signal path. The shorter the signal path is, the less possibility of sonic degradation from various sources, including the wire itself. Even on the circuit boards, the copper traces are kept to a very minimum length. The completely redesigned circuit board provides a more straightforward and direct approach to the signal paths.

Logical sequenced soft-start power up for extended tube life
Power tube and electronic protection circuit system
0dB negative feedback  (of any kind ) 
Ultra short signal path
Simplest direct circuit path for purest musical sound and high reliability
No solid state devices in the signal path
High current and low impedance design that operates tubes in the best areas their curves
Minimal discrete wiring for optimum signal propagation
Automatic and manual bias adjustment
No followers or buffers in the signal path
High quality parts throughout

Power Supply
The power supplies have been further refined with new components and enhanced AC line noise filtration. Separate power transformers, chokes and filters provide total isolation between the input and output stages which makes this a pure power source. We also use electrolytic capacitors with much larger storage capacity to make up for the loss in filtering when using resistors in lieu of inductors.

2 Low noise –insulated power transformers
Power transformer is encased, excellent damped and RFI/EMI shielded
Innovative power supply provides a high speed energy delivery on transients
Dual choke filtered power supply for power tubes
Choke for pre and driver stage
Separate and isolated power supplies over each stage of amplification
Regulated DC filament supplies with soft start
AC power line filter to avoid noise and hash from entering into the unit.
High capacitance energy storage. 
Current in-rush limiting
Auto sequencing - Power on cycle completes in 1 minute

Dual Grounding System
The modification of the grounding topology leads to increased rejection of noise from the power supply and other areas.
The dual grounding topology used in all of our amplifiers is quite unique to the whole hi-end tube amplification industry. Such extensive topology provides for quieter backdrop for which the music can unfold in its entirety. It further establishes the quick and controlled bass response and the full bodied expression of the high frequency. The ground leg of the signal has not been neglected and given meticulous attention in its implementation. The importance of proper grounding cannot be over emphasized.

Ground switch
Central one-point star earth grounding
Dual grounding system (switchable)

Output Transformer
The super-wide bandwidth output transformer’s major strength is that it can deliver the current in the bass, while at the same time maintaining the speed in the high frequencies, dramatically improving the square wave response of the amplifier. The effect is a much more natural and relaxed sound with much better clarity, resolution and fluidity.

Super-wide bandwidth high performance output transformer
High efficiency with low insertion loss for optimal current and voltage transfer
Multiple tight layering and coupling for extended frequency response
Output transformers are sealed with an anti-resonance compound material

The type of parts used therefore must have a synergistic relationship to the circuit they are placed in. It is this relationship of which type of part to use where, that ranks our products apart from the mass.

Selected, premium quality passive components used in all applications
High speed  & high quality audiophile grade coupling capacitors
Special tube sockets with beryllium- copper spring pins, custom made by Ayon
Ayon high quality – binding posts
High quality – RCA input jack
Neutrik/Swiss - XLR chassis connectors
Special isolated - internal wiring
Silver-copper matrix - internal signal cable
Gold-plated industrial grade PCB
All wiring to the circuit boards is done with the use of special pluggable pin-connectors. 
This is done for easy of repair should ever the need arise.

High Grade Speaker Binding Posts
The new ayon gold plated solid body speaker binding posts provide performance levels that are truly in the very High End. The solid body construction ensures that there is no gap or breach in the flow of electrons. The gold plating provides for superior contact and resistance to oxidation. These binding posts are chosen primarily for their sonic performance, edging out even more expensive counterparts.

Mechanical Construction
The high grade aluminum chassis impart a richer, more lustrous tonality with a cleaner background and less hash and grain. All brushed anodized anti-vibration-resonance and non-magnetic chassis’s are fully hand assembled to insure the highest level of craftsmanship.

Improved heat ventilation chassis
The aluminium feet are resonance absorbing types
Backlit “ayon” logo
All front & rear panel descriptions are engraved
Ground switch
AC phase polarity control indicator  
Chassis finish: black / chrome


Class of Operation: Triode* or Pentode mode, Class-A*
Tube Complement: 6x KT150 std (KT88 optional)
Load Impedance: 4 & 8 Ohms
Bandwidth: 8Hz - 70kHz
Output Power / Pentode mode – KT88 = 150w / KT150 = 180w
Output Power / Triode mode – KT88 = 80w / KT150 = 100w
Frequency Response; 10 Hz - 60 kHz
Input Impedance at 1 kHz: 47 KΩ
Input sensitivity ( full power ): 900mV
S/N ratio at full power: 98 dB
NFB: 0dB
Inputs: RCA & XLR
Dimensions: 350W x 550D x 250H mm
Weight: 40 kg ea
Specifications subject to change without notice


The Epsilon could be the first choice for you. they are for me,

SUMMARY: whether you are looking for power amplifiers with immensely inexhaustible power reserves, a conspicuously extensive spatial representation, great detail inflexibility and despite all the ability to analyze a charming touch of warmth, without compromising on everyday life and reliability The Epsilon could be the first choice for you, they are for me. 

EXRENDED REVIEW (translation): Tube versus transistor, analogue to digital: these debates certainly had their charm, but for me, but since the rapid development of the high-bit and DSD technology snow yesterday. Completely free of ideology, it is a question of the sound of tubes, not least thanks to a good portion of high-tech. In short, it is about Ayons Epsilon - and the new KT150.

The longer I am concerned with Hifi , the less I dare to attribute certain sound characteristics to a circuit concept or detail . And, last but not least , it does not matter in principle which active components in my hi-fi components are responsible for the amplification . The first power amp of my Hifi story, which together with an Audiolabor preamplifier replaced a powerful Onkyo full-amplifier , was a Michaelson & Austin TVA-1, in which two KT-88 Gold Lion push-pull 75 watts . That she later had to give way to a transistor amplifier, lay alone because it did not harmonize with my new dream speakers. 

Although I have been using an analog drive with a tube section and a preamp in which tubes are at least partially amplified, I have never come to the reputation of being a tube fan. If you like to hear loudly and use a loudspeaker with a not even so low efficiency of 91 decibels for high-efficiency loudspeaker enthusiasts but still ridiculous, there would also be a lot of tube amps that have the necessary power, but my device selection Was never determined by the question tube or transistor.

The fact that an Ayon Epsilon has now landed with me is not that Jürgen Saile, who, as I like to say, knows every tube with first names and accordingly acts as a monopolist for all the glass- mounted devices in hiphadatement , for an amp of this performance not the right, say "efficiency weak" speaker has, but that after I the mishap with the exquisite, but critical impedance Göbel transducers, yet always on the lookout for new amplifiers for my listening room Ayon chief and LumenWhite sales GerhardShepherd asked for a proven game partner for the DiamondLight . He recommended the brand-new Epsilons and made a short decision

A couple to Gröbenzell. There, they would still give the author a lot of joy without any thought of a test - if not the KT150 had provided for a lot of unrest among the tube friends. There was the idea to convert the Epsilon to the new end tubes. A previously unknown Ayan output stage, which has also been equipped with one of the most exciting new tube developments of the past few years, to be alone in working and enjoying in my listening room, seemed to me too selfish. But before I report on my experience with the Epsilon, I let Jürgen Saile speak up, who can describe the technical characteristics of amplifier and tube far more competently than I do.

Jürgen Sailes Technical Excursions:
The Ayon Epsilon can be ordered in different versions, once equipped with KT88 power tubes or with the new KT150. The KT 150 is a new tube type developed and manufactured by the Russian company Tung-Sol. It belongs to the family of Beampower Tetroden and is therefore related to the famous KT88, or rather, emerged from it. With an anode loss of 70 watts, however, it represents a different caliber and is currently the most powerful beam bundle tetrode. A doped KT88 so to speak. If you look closely, you can see the anode small spoilers. They should make the Tetrode even faster ... nonsense, of course serve the heat dissipation.

The somewhat unusual shape reminds somehow of Easter, and was developed by the Russians to ensure a better heat radiation. In addition, Tung-Sol promises a lower propensity for microphony. The KT150 is pin-compatible with other KT types, such as the KT88, but requires higher heating currents compared to an ordinary KT88. A simple changeover is thus not so easily possible. The Epsilon is fully balanced with six KT150s per device. This allows the output power to be increased again compared to the KT88 version, namely to 180 watts. If this performance is still not enough, you should be serious about your loudspeaker.

As is customary with Ayon, a lush supply of mains power is of great importance. This is not the case with the Epsilon, the three chrome-plated pots contain two mains transformers, one for the anode voltage and one for the heating voltage. The third contains the output transformer. The pots are filled with an epoxy potting compound, which is to make the last vibrations the cooking out. Inside the housing, there is another transformer for the supply voltage of the control electronics. Thus, not enough, the anode voltage is additionally filtered through two chokes and a capacitor bank in a CLCLC configuration. The capacitor bank can have over 1700 μF of screen capacity; This may seem a transistor fan mickrig, but we must remember that voltages of 400 V and more are present. The driver level also contains a choke for filtering. This is very complicated!

In addition to the armada of KT150 tubes, there are four comparatively tiny tubes, two 6SJ7 pentodes with an American octal base as well as a 12AX7 and a 12AU7 with the European base of the Novalsockel. These two tubes are the American counterpart to ECC83 and ECC82. The 6SJ7 Pentodes (these are the tubes in the black metal case) are NOS goods, ie tubes, which were produced earlier and which have hitherto been unused in some store. The use of these tubes has nothing to do with money, quite the opposite, these old tubes have a quality standard, which is hardly achieved in the productions these days.

The output stage has four stages. First, the signal passes through the input tube, which provides the necessary voltage amplification of the LF signal; The Epsilon assumes the 12AU7 double triode. Since the amplifier is designed to be fully balanced, one half of the triode is responsible for both positive and negative. Then it goes over a 12AX7 double triode to the driver stage. Here a powerful driver tube is needed, which makes the KT150 not limp. Ayon uses the 6SJ7, which is switched as a triode for reasons of sound. The KT150 triple packs work in push-pull configuration.

Another specialty is the BIAS setting. We remember that each tube requires a certain grid bias, with which it can work at the optimum operating point. This changes in the course of the life of a tube and must always be readjusted. On some devices this works manually by means of setting potentiometer, in some cases, this is also automatically controlled. The latter has, of course, the advantage that one has to worry about nothing more. Unfortunately, these circuits are often accompanied by a loss of sound, so that Ayon has devised something different. Under the designation auto-fixed-bias the regulation also works automatically, but should function without the mentioned sound losses. The regulation does not interfere with the signal path nor does it regulate during operation.

The Ayons spent a longer time in my listening room, but not with the new KT150. Gerhard Hirt brought me a few months ago the standard version with the KT88. At the speed is quite specific that he packed the two epsilons including inserted tubes without further packaging in his already almost completely full car - which not all power amplifiers really goutiert. Without thinking about this unsuitable transport, I then happily connected the two optically appealing amplifiers and was equally enthusiastic about their sound: There was a touch of extra fullness in the upper bass for the LumenWhite to go a little less strictly , Suddenly also did not one hundred percent perfectly recorded and produced recordings fun, Where they were too relentlessly drawn to their mistakes. And the best thing: despite this small extraportion warmth, the DiamondLight lost almost nothing of its fantastic tracing and the enormous detailfulness. The spatial image even succeeded a little more convincingly than with the multitude of the amplifiers so far used in my chain.

The joy, however, lasted only a day or two, before she had a bump ended. Unfortunately, this was not a real timpani, but the bang of a tube, which during the playful operation blessed the temporal. You can imagine my horror. It was not about the Ayon, but first about my loudspeakers with their not cheap chassis. So I quickly joined the cello monoblocks - and was relieved to find that the protection circuits of the Epsilon were fast enough to save the DiamondLight from too much current. The loudspeakers had survived the incident undamaged. I was already thinking about a longer repair time for the epsilons, when I called Gerhard Hirt. He said, however, quite calmly that it was extremely unlikely that the defective tube caused damage to the amplifier. I should simply insert a spare tube, start with a mini screwdriver the tube test and calibration program and wait for what happens. The likelihood that a resistance would have been affected would be in the perimeter range. And so it was: After a few minutes, in which the Ayon worked out their test routine, she switched to the normal operating mode and played as fascinating as before. 
I would not have dreamed of a new, elaborate tube design as much as I could have done with everyday life. In which the Ayon worked out their test routine, switched it into the normal operating mode and played as fascinating as before. I would not have dreamed of a new, elaborate tube design as much as I could have done with everyday life. 

As a result of the somewhat rough transport over 500 kilometers, another tube has been adopted, but completely unspectacular: In the usual bias current measurement after switching off the power amplifiers, a fault was detected, one of the six LEDs on the rear of the amplifier signaled , Which tube should be exchanged and the illumination of the Ayon lettering blinked instead of going out. I disconnected the Epsilon from the network, replaced the incriminated tube, restored the mains connection, and started the test and calibration program again. After a few minutes, the Epsilon sounded as if nothing had happened. If you are wondering why I am describing these two small incidents at all, when only the positive experiences with test devices can be read almost everywhere: First, Because I would like to emphasize once again that it is in no way beneficial for the sensitive glass flasks to be transported in the amplifier instead of in the protective cardboard box - even over short distances. And secondly, to encourage all those who prefer the sound of tube amps to those of transistor amplifiers, but still do not invest in the former for fear that tubes are particularly susceptible and thus not very everyday, to follow their sonic preferences and to raise concerns - At least when the objects of Ayon's desire are descended or just as secure as the Austrian high-tech amps.

So it took me a few weeks before the epsilons returned to my listening room. Even the best acoustic memory is not enough to describe the changes in the sound caused by the change of the tube. Overall, the more powerful tubes play a more lucid and more relaxed way to deal with impulses all the more violently. The fact that the power amplifiers are still absolutely undisturbed even at fairly high levels is also manifested in a spatially wide and enormously stable sound picture, in which a wealth of details are integrated playfully and completely automatically. But bestsellers in a variety of hifi disciplines reach many very good amplifiers. The outstanding single performance will be a coherent, emotionally captivating experience, But only the best representatives of their kind. The Ayon Epsilon is one of them.

What makes me so much for the epsilons, is the pressureful Oberbass area and this certain warmth. These are characteristics that are often called for, but to avoid misunderstandings: the epsilons are far from what is commonly known as a tube sound: they do not allow any smearing effects, have the bass chassis firmly under control and do not tend to Euphony. They do not turn poorly made discs into drugs for audiophiles, but are not quite as ruthless as some of their transistorkolders. For me, the Ayon are the almost perfect addition to my existing chain.

Since I am happy with the sound of the epsilons, I do not really know why I should use the KT150 Pentodes as trimes. But first, the Ayon offer this mode and secondly the colleague mold was in the test of the Cayin amplifier in Triode mode so excited that I can not just ignore this kind of game. So I do not then quite prejudice-free to the comparison, whereby due to the switching-off procedure of the epsilon between the two versions of the same piece pass up to five minutes. With Ravi Shankar's "West Eats Meat", the instruments in the room are somewhat more plastic in triode operation, the playback becomes a touch of air. The deep timpani and the electric bass have more pressure and contour in the Pentode circuit. Here are the KT150 in their former mode of operation for me first choice. At Keith Jarrett's Cologne ConcertThe decision is even more difficult: The triode circuit lets the piano sing just more intensely, the sound picture appears more closed, Jarretts play emotionally even more gripping. For this reason, the pentodes in the mode according to the mode of operation allow the individual tones to sound even more differentiated in their positioning in space and in the dynamics. This comes a bit closer to the somewhat sobering lecture, which I had been accustomed to over the years by transistors. But after a few months with the KT88 equipped Epsilon, I can not assert a more calm conscience, which - let's call it: - the intellectual-analytical mode of the more emotional.

Today I am more concerned with the question whether the tube amplifiers in the pentode or triode operation fascinate me more. Since the chain in my study should have tool-character, but I will stay with the Pentodes for the time being - but I can not and will not rule out the charm of the triode circuit more and more often. How nice that the Ayons have a choice here. The change-over switch is therefore not as superfluous, as at first sight.

Am I after these tremendously positive experiences with the Epsilons from now tube fan? For me a rather idle question: I remain synonymous in the future all circuit concepts open up - digital amplifiers perhaps excepted, because before the A / D conversion of fine analog signals from record player and tape recorder still frightening back, Epsilon and KT150 fan.

Whether you are looking for power amplifiers with immensely inexhaustible power reserves, a conspicuously extensive spatial representation, great detail inflexibility and despite all the ability to analyze a charming touch of warmth, without compromising on everyday life and reliability The Epsilon could be the first choice for you. they are for me, they are for me. 

PS: perfectionists are not around the equipment with the KT150 not around, but also with the standard KT88 guarantee the Ayon enormously much music enjoyment.