˻ PREMIERE ˼

⌈ FEZZ AUDIO is a company specializing in tube amplifiers. It is the audiophile brand belonging to the toroidal transformer manufacturer TOROIDY.pl, that are also used for audio applications. Fezz Audio was founded in 2014, and its first product was the LAURA integrated amplifier. We are testing its most powerful integrated amplifier, OLYMPIA. This is its premiere review. ⌋

IF YOU ASK AN AVERAGE AUDIOPHILE, assuming, of course, that such a thing as an “average audiophile” exists, because it is, after all, a very diverse community and the people in it are anything but average, what they think a good audio amplifier should be characterized by, they will probably say high output. Supporters of high-efficiency speakers will, of course, answer exactly the opposite, but I assume that the majority will pay attention to this aspect.

Power is an understandable and relatively easy to measure characteristic. In the industry, there are several measurement methods that take into account the operating time of the device, the assumed distortion, the frequency response, the measurement length, etc., which in the past has led to many misunderstandings and often to misrepresentations. Those of you who remember the invasion of cheap Japanese portable systems will probably also remember the large stickers on their speakers, shouting 100, 200, 500, or even 1000 W!!! (exclamation marks were also part of this message).

It was silly, but in a way it was true – in an extremely short time and with a limited bandwidth, even small speakers can produce that much power. This says nothing about their actual capabilities, but it sends a certain message out into the world. Today, the consensus in audio is moving in a slightly different direction – power is important, of course, but current efficiency is even more important.

And this kind of power allows for the perfect operation of small amplifiers with a fairly wide range of speakers in fairly large rooms; if you are interested in the measurement methodology, I refer you to an interesting article in the “Stereophile” magazine: The FTC Updates the “Amplifier Rule”, more → HERE.

Sometimes, however, output is what it used to be – pure POWER. When we listen to music with particularly difficult speakers, that is, with low efficiency and low impedance combined with a large phase shift, and if we listen to music loudly, which can be rock or classical, then physics does not allow for anything else than choosing an amplifier with more than twenty to thirty watts. For example, the Fezz Audio Olympia Evo integrated amplifier, which offers 100 watts per channel.

▌ Olympia Evo

I WONDER WHEN FEZZ AUDIO will reach its limits. That is, when it will have developed amplifiers based on all the popular power tubes. The range of this Polish manufacturer currently includes as many as five tube integrated amplifiers, two of which are available in various versions.

These include SET amplifiers, i.e. single-ended triode, based on single and parallel 300 B tubes, on single 2A3 tubes, one can also find classic push-pull amplifiers, for example my favorite model Silver Luna Evo (also in the Prestige version), and Titania. If it were possible, I would also include amplifiers with even more powerful KT tubes and single-ended pentode amplifiers – EL34 and KT88/120/etc. – at least as long as we are talking about currently produced tubes that can be precisely matched.

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| A few simple words…

MACIEJ LACHOWSKI
Owner, and designer

Photo by Fezz Audio

OLYMPIA WAS THE NATURAL NEXT STEP in the evolution of the Olympia monoblocks that Fezz had been offering for six months. Since our amplifiers are produced in several standard sizes, we did not have as much space as we would have in a new, larger housing. The position and size of each component had to be carefully considered so that nothing collided with anything else, and speaker transformers or sensitive input circuits did not pick up interference from chokes or power supplies. I will gladly admit that it worked out well, really well.

Last year, a young engineer named Jakub Korpacz joined our team. And it is thanks to his ingenuity that we have elevated Olympia to the highest technical level in Fezz's history.

The solution we applied, in combination with a carefully designed voltage amplification system and toroidal core output transformers by Toroidy.pl with very low leakage inductance, unattainable for molded transformers, resulted in an amplifier with a wide and even frequency response, which, in terms of power and distortion, enters the territory previously unattainable for tube amplifiers.

We have decided to introduce an expansion card slot as a new solution. For the time being, the Bluetooth module is available, but in the coming months we will expand the offer by five additional options: MM phono preamplifier, DAC with USB input, DAC with Toslink input, additional RCA input and additional XLR input. Everything is very easy to install and requires virtually no technical experience. Just remove two screws on the back panel, connect the selected card to the ribbon cable and screw the screws back on.

Many people ask me if Olympia is the top Fezz amplifier. My answer is “no”. It is an equivalent amplifier to the Lybra 300B, but intended for a different type customers. We dedicate Lybra to systems with high-efficiency speakers, e.g. horn speakers, i.e. where power is not a key parameter, while Olympia will simply drive any speakers. ML

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OLYMPIA IS THE NEWEST amplifier in Fezz's product range. It belongs to the Evo series, designed by Tomasz Pydo, Katarzyna Borkowska, Jacek Nosiła and Jan Wilczak, for which the Polish manufacturer received the prestigious Red Dot Award in 2023. The logo, which was also new for this series, was designed by Dominika Wysogląd; more → HERE ˻PL˺.

This line is characterized by excellent external design and a choice of seven colors for the housing. Even their names have been “thought out”: Big Calm, Republika or Bartosz Łuczak's favorite color, which he uses for “High Fidelity”, Evergreen.

TECHNOLOGY • Olympia is the most expensive integrated amplifier in the Fezz Audio's history. As mentioned before, it delivers up to 100 W output per channel with low distortion of less than 0.1% below 100 W and less than 1% at full power. The manufacturer also specifies a wide frequency response for a tube amplifier: from 16 Hz to 80 kHz.

High power is achieved by using two pairs of KT88 tubes per channel, working in a parallel push-pull configuration. In turn, such a wide bandwidth is achieved by using self-made toroidal output transformers - unique in the industry. The power transformer and choke (!) are also toroidal. The preamplifier and phase inverter use the popular ECC82 and ECC83 double triodes.

The Fezz Audio website states:

Olympia is an integrated tube amplifier in dual mono configuration. The device, based on eight KT88 tubes, offers a truly captivating sound. Its character combines powerful dynamics with sophisticated timbre, creating a unique spectacle. (…) The new remote control allows you to adjust the volume, select the source and turn the device on and off.

The amplifier also features a convenient standby mode and a two-minute warm-up cycle, which guarantees optimal operating conditions and extends the lifespan of the tubes. In addition, there is a slot for an optional expansion card for additional functionality, increasing the capabilities of the device.

⸜ Fezz Olympia Dual Mono Amplifier, → FEZZAUDIO.com, accessed: 25.02.2025.

As one reads further, tubes in this device are protected electronically, rather than by traditional safety fuses. This, together with the anode voltage delay system, should reassure those who associate tube amplifiers with difficult operation and failure rates. The same goes for the automatic bias control and correction system, which, according to the manufacturer, “ensures optimal sound quality and eliminates the need for adjustment”.

As you may have noticed, the device is a dual-mono design. This means that both channels are routed independently. This reduces so-called “cross-talk”, i.e. the influence of one channel's signal on the other. Usually, this is an incomplete system of this type, with a common power transformer, possibly with separate secondary windings for the left and right channels. In this case, it is true - there are two separate power and amplification paths.

FEATURES • The tested Fezz Audio amplifier’s looks are very attractive. I know, I've already said that, but it's impossible to ignore such a good design. It works even in a project as big as this one. Big, meaning with the top panel filled with tubes.

The device is a classic audio amplifier, i.e. there is no digital-to-analog converter or file player on board. It offers three line inputs, which seems like reasonable restraint in this day and age. There is also a direct input to the power amplifier stage. It can be used to connect a source with adjustable output level if you want to bypass the potentiometer in Olympia, or to include it in a home theater system. But in the future, you can also buy an external preamplifier and use Olympia as a power amplifier – a high-power one, at that. And there is also a line output for a sub-woofer and a switch to disconnect the ground from the housing.

Under the cover plate to the left of the RCA input and output sockets, there is a slot for a Bluetooth 5.0 receiver module. Apart from the electronic protection circuits for the tubes, this is the only concession to modernity. Once the module is in place, it will allow wireless transmission of a digital signal from a smartphone, tablet or computer. This will be a compressed signal, as is the nature of this type of connection. Version 5.0 offers a fairly large range of up to forty meters indoors and up to two hundred meters outdoors, which is completely sufficient for comfortable use of music services.

The device can be controlled with two large and comfortable knobs on the front panel or with a remote control. After major problems with previous remote controls, the company switched to a new platform offered by another subcontractor. The new remote control allows you to adjust the volume, select the source and turn the amplifier on and off. There is also an option to purchase a set of “Premium” tubes, which offer even better performance than the basic ones - they are sourced from Genelex.

A protective cover for the tubes is included in the set. It used to be available as an option, but here it is a standard feature of the amplifier. You have to assemble it yourself by screwing the acrylic front onto the metal element. It is not very handy, but it works.

REMOTE • The new remote control works in the classic way, using infrared. The characteristic “window” with the receiver had to be added to the front panel of the amplifier. The remote control housing is made of milled aluminum, and the electronics are manufactured for Fezz, it is not an “off-the-shelf” system. The buttons are reliable, even though they tend to “float” in the holes. There is one thing missing: a “Mute” button. The remote control is only available in silver. I wonder if one could order it in the same color as the amplifier for an additional charge?

▌ SOUND

HOW WE LISTENED • The Fezz Audio Olympia integrated amplifier was tested in the HIGH FIDELITY reference system and compared to the Solution 710 power amplifier, paired with the Ayon Audio Spheris III tube preamplifier.

The tested device was placed on the Finite Elemente Master Reference Pagode Edition Mk II rack. The source in this system were the Ayon Audio CD-35 HF Edition SACD player and the Lumin T3 file player. With the Ayon Olympia was connected using the Siltech Triple Crown RCA interconnects, and with the Lumin via Siltech Master Crown. The Harbeth M40.1 speakers were connected to it using Crystal Cable Art Series Da Vinci cables.

The amplifier was powered using the Harmonix X-DC350M2R Improved-Version cable. It should be added that the speakers were connected to SPEC RSP-901EX speaker filters, which the manufacturer describes as a Real-Sound Processor (more → HERE).

» RECORDINGS USED FOR THE TEST ⸜ a selection

⸜ FRANK SINATRA, Sinatra Sings Gershwin, Columbia/Legacy/Sony Music Entertainment 507878 2, CD (2003).
⸜ DOMINIC MILLER & NEIL STACEY, New Dawn, Naim naimcd066, CD (2002).
⸜ R-MEN, I thought about you, T-TOC Records MCDR 3002, „Platinum Gold Sound”, Master CD-RIIα (2010).
⸜ JASON ISBELL, Foxes in the Snow, Southeastern Records/Tidal, SP, FLAC 24/96 (2025).
⸜ ZOE WESS, Traitor, Valeria Music/Tidal, SP, FLAC 24/96 (2025).
⸜ EXPLOSIONS IN THE SKY, American Primeval, soundtrack, Netflix Music/Tidal, FLAC 24/48 (2025).
⸜ SHURA, Richardson (feat. Cassandra Jenkins), Play It Again Sam/Tidal SP, (2025).
⸜ SAM SMITH, Love Is A Stillness, Universal Music Operations Limited/Tidal, SP, FLAC 24/96 (2025).
⸜ GARY LOURIS, Getting Older, SHAM/Tidal, SP, FLAC 24/44,1 (2025).

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MY PERCEPTION OF THE KT88 TUBES was shaped by my experience with classic amplifiers featuring them, such as QUAD II and → MCINTOSH MC275 (more → HERE). They were very good, successful design, designed by engineers and listened to by music lovers. I liked and respected them very much.

However, the more often I came across new designs of this type, the more I mentally moved away from beam tetrodes. In my opinion, they lost something important and started to fight for power. The culmination of this trend was the flood of amplifiers using powerful KT120 and KT150 tubes. Rarely did a device take full advantage of what these tubes have to offer. That is why, as you can see by reading my reviews of products such as Fezz Audio Silver Luna, Leben CS600X or Kondo Overture II, I favored EL34 tubes. And it was only Olympia that reminded me of what KT88s are capable of and how they can become the center of a system built around them.

This amplifier sounds incredibly silky and smooth. The FRANK SINATRA’S album Sinatra Sings Gershwin, which I played at the beginning of the tests, is a test for me of the tonal balance and the device's involvement in the music, if I can call it that, which is in my head. Not only the second track on this album, ˻ 2 ˺ I've Got A Crush On You is an incredible example of recording technique from the pre-tape era, and each of the tracks on the album sounds different and requires not only tonal balance but also high resolution.

The thing is that if the timbre is not saturated and full, some of these pieces sound bright. And if the resolution is too low, then they sound flat and have low energy. The Polish amplifier played them all remarkably well, not only in terms of its price, but compared to much more expensive competitors. It played them densely and deeply, but without warming them up. And with incredible energy, although hidden under the hood of calm. As if it were in control of everything and had nothing to fear.

And that's probably how it is, it's an amplifier in which the power is used in the right way. Not for pumping bass or pretending to be dynamic, but for energizing the air in the room in such a way that we don't even notice it. Although I could have expected it, I was still pleasantly surprised by how the amplifier conveyed the wonderfully deep, dense and low guitars from DOMINIC MILLER'S and NEIL STACEY’S New Dawn. It played them in a very similar way to what I remembered from listening to another excellent Polish amplifier, → MORE AUDIO CS100 ˻PL˺.

In absolute terms, there was a slight emphasis on the mid-bass in Olympia, thanks to which the scale of the events was large and the sound was tangible, even very tangible. But I prefer it that way rather than the other way around. All the more so because the treble is sonorous and strong with this amplifier. It's just that it's not bright. The Fezz Audio is not a device that produces dark or warm sound. We perceive its sound as somewhat warm, but this is not due to coloration, but to the naturalness of the sound.

When we listen to the ˻ 1 ˺ Orbits or ˻ 2 ˺ Circle, the tracks on the Miles Davis Quintet album Miles Smiles, we can clearly hear the intensity of the drums in the left channel, and we also have a clear image of the leader's trumpet in the center, which changes every now and then with Wayne Shorter's saxophone. It is a powerful, open, and spirited performance, fully controlled from start to finish.

What is this control thing all about? – It is about something that only results from well-utilized power. I have written about it several times, I will repeat it again: power corrupts and distorts the picture by itself. The greater the uncontrolled power, the worse the effects of its use and the less certain the results. This is true in politics, sociology and audio. To use it, it must be perfectly mastered. Like here, like in the Fezz Audio amplifier.

That's why I reached for some albums I hadn't heard in a long time, which had made a big impression on me at the time and which made many devices disappoint me, or at least “not move me”. Like I Thought About You by the Japanese jazz band R-MAN. The T-Toc label that released it is part of a group of freaks who refine every aspect of their releases, no matter how small. This one was burned onto a CD-R using a special process, not from a computer memory, but from a FLASH drive. At the time when they started, people laughed at it and only recently it became clear that it made sense; more in the article CD-R: Master Voice → HERE.

This album sounded dark, low and extremely dynamic. There was a strong, resonant treble and a full, warm midrange. But it was the dynamics that caught my attention, because that is something we get when we switch from the excellent Silver Luna model from this manufacturer to the Olympia. I say this with some surprise, but in this case, both the higher power and the KT88 tubes translated into a big, really big leap in sound quality, in every respect.

When producers place vocals close to us, when they open up the treble range of the guitar, as in JASON ISBELL's excellent digital single Foxes in the Snow, which heralds his album of the same name, they usually want to convey the expressiveness of the performance. The Polish amplifier conveyed this wonderfully, with a short reverb on the guitar and a slightly longer one on the vocals, without mixing the two sounds, just as it did not confuse the warm and big vocals with the open, metallic sound of the acoustic guitar.

This was the case with the acoustic, intimate track. But exactly the same, i.e. with full control over the events, but also so that everything sounded perfectly smooth, the amplifier sounded with the next new single, which I used several times this month to listen to the devices, this time Traitor by ZOE WESS, with incredibly deep, synthetic bass. I have already mentioned the low tones, but here it was clear that the amplifier can handle most speakers even in large rooms. It is not a contoured and selective bass, yet it sounds clear.

It seems not to make sense because it should either/or situation, but we are sitting in front of the speakers and we are not being attacked by the hard leading edge of the sound. There is also no bass blooming, even in such dense playing as in the soundtrack from the American Primeval movie or in the calm, summery playing of SHURA, accompanied by Cassandra Jenkins, who met in the song Richardson, the second single from the album I Got Too Sad For My Friends, which will be released on May 30th by the Play It Again Sam label.

The vocals, widely spaced by means of phase shifting, did not break up the fullness of this piece, did not lead to its disintegration. It was a strong, full-bodied performance with warmth flowing not from the warming of the sound, but from the music itself, from the fullness of summer, when we will finally be able to take the record in our hands.

▌ Summary

LET ME START THIS WAY: it's the best Fezz Audio amplifier I know and one of the best tube amplifiers at relatively reasonable price level. There are other options, some better in some aspects and worse in others, but when it comes to the overall vision, Olympia rules.

It's all about how it organizes the presentation. It is in perfect control at all times, it is composed. But at the same time, it has all the characteristics of open, fast, explosive playing, which we do not usually associate with control, but rather with the low output power of amplifiers and high efficiency speakers. The Polish amplifier controlled the Harbeths as if they were born in the same workshop.

Listening to it in the right environment, we will get perfect bass, because it is colorful and controlled, as well as deep, and at the same time every sound from the upper end of the band will be perceived as polished and delivered on a golden platter. And all this with exceptional dynamics. Everything I am talking about is somewhat subconscious, however, because the high resolution means that everything is brought together here, harmonized, and works together for the better. An excellent amplifier! That is why we are awarding it with the ˻ RED FINGERPRINT ˺.

▌ DESIGN

THERE ARE SOME ARE HEAVY AND REALLY HEAVY AMPLIFIER OUT THERE and Olympia is one of the latter. Although it weighs a moderate 24 kg, this weight is concentrated in a small area, making it seem heavier than it actually is. Therefore, it is best to carry this device, which measures only 420×380 x 200 mm, with a friend. It is also possible to carry it alone, but why would you want to? The device stands on four rubber feet. Normally, I would say that they need to be replaced with anti-vibration feet, but the ones on Olympia look so nice that I don't have the heart to suggest it.

FRONT AND REAR • The housing of the Evo series amplifiers is made of precisely fitted steel plates bolted to a steel frame. It can be finished with one of several colors, and in each one - I think I've seen them all - the paintwork is of high quality. The output transformers are enclosed in round, black-painted boxes, and we get a metal protective grille with a transparent front to protect the tubes from us and us from the them.

The front features two large metal knobs for the volume control and input selection. One of them is also a switch to turn the device on and off (“standby” mode). The knobs, in every color version, are silver, which really suits the design well. The laser-cut logo in the middle is illuminated - the LEDs are enclosed by an aluminum block. The power switch is located underneath, at the front edge.

On the rear panel, you will find RCA inputs and outputs using very decent sockets. It is worth remembering that Fezz Audio mounts them the other way around than is currently accepted, i.e. the right channel (red) is on top and the left channel (black) is on the bottom. This is a practice introduced years ago by Mark Levinson and is still used in Poland, for example, by Haiku Audio. There are also small gold-plated speaker sockets - separate for 4 Ω and 8 Ω impedance.

The tubes are plugged in from above into gold-plated sockets with ceramic bases. Their markings are applied with a black, glossy varnish, so they are discreet. Red LEDs are also placed between them to signal the activation of the automatic protection system.

Olympia features three types of tubes: ECC82/12AU7 and ECC83/12AX7 double triodes and KT88 beam tetrodes. The former is a Genelex Golden Lion made in Russia, while the KT88 was produced by the Slovak company JJ Electronics (by the way, Slovakia is also home to the largest ammunition factory in Europe). The ECC82 does not bear the manufacturer's logo, but it does have the logo of the company that measured and selected it. These are the wonderful TAD (Tube Amp Doctor) tubes, a selected and measured version of this classic double triode. And quite expensive. TAD is a German company specializing in the selection of tubes from the golden era of the British tube industry. Great!

INSIDE • After unscrewing the bottom panel, we can see that the description on the front panel, “Dual Mono Amplifier”, is true. The power supply and the amplification section are separate. The only thing they have in common is the board with input sockets, switched by relays. They are activated by a switch on the front panel, from which the impulse for the change is sent via a computer-style ribbon cable.

The signal from the gold-plated RCA inputs runs to the front, via a rather long computer ribbon cable, to the Alps rotary potentiometer. So it turns out that we are talking about a system with a potentiometer at the input of the preamplifier section. And only from there signal goes to the amplifier section.

The entire amplifier circuit has been assembled on two large printed circuit boards. For the first time, I can see the name of the circuit designer on them – in this case, it is Jakub Korpacz. The circuit boards have gold-plated tracks. The components used on it are very nice. These are, for example, Wima polypropylene capacitors and serious-looking metalized thin-film resistors.

The designer wrote the following about his work for us:

One of the main obstacles were the PCBs with the microprocessor-based bias current regulator. There was simply no room for them in the new amplifier. These clever modules, which were developed in cooperation with Andrzej Starzyk (owner and designer of Looptrotter, a company that produces high-tech devices for the pro audio industry), combine the advantages of fixed bias and the maintenance-free nature of automatic bias. In Olympia Dual Mono, I decided to approach this problem from a completely different angle – completely analog. I designed a continuous automation system that performs exactly the same task without entering the digital world.

Without exaggerating too much, it can be said that the bias automation system is the heart of this amplifier and it is this system, in combination with the balanced architecture of the entire amplifier (all tubes work as differential stages), that is responsible for its performance. The challenge was to design a system that would be insensitive to the presence or absence of a music signal. The variable component of the idling current (audio signal) interferes with the operation of most solutions of this type, causing an increase in distortion and shifting the operating point of the amplifier to deep class B. The key was to develop an integrating circuit that would only work in a very narrow window and would therefore be transparent from the point of view of the audio signal.

The power supply is also advanced, with large main transformers and smaller toroidal chokes operating in a “Pi” filter. All six toroids were manufactured by Toroidy.pl, the parent company of Fezz Audio. The power supply features eight larger and four smaller filter capacitors per channel. A separate board, shared with the input switch, is occupied by the remote control system with power supply for standby mode.

As usual with Fezz Audio, it is a clean, solid, well-designed, and great looking device. I also have the impression that in the tested Olympia, the company has taken another step forward in terms of build quality ●

▌ Technical specifications (according to the manufacturer)

Nominal output: 2×100 W
Tube complement: 8x KT88 + 2x 12AX7 + 2x 12AU7
Inputs: 3x RCA + direct
Optimal speaker impedance: 4 or 8 Ω

THD: <0.1% (below 100 W), <1% (@ full power)
Frequency range: 16 Hz – 80 kHz
Damping factor: >30
Input impedance: 50 kΩ
Input sensitivity: 0.7 V

Power consumption: 350 W (idle), 700 W (full power)
Dimensions (W x H x D): 420×380×200 mm
Weight: 24 kg
Accessories: tube cage, remote control, HT, direct, sub out
Optional accessories: premium tubes, Bluetooth module

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THIS TEST HAS BEEN DESIGNED ACCORDING TO THE GUIDELINES adopted by the Association of International Audiophile Publications, an international audio press association concerned with ethical and professional standards in our industry, of which HIGH FIDELITY is a founding member. More about the association and its constituent titles → HERE.

→ www.AIAP-online.org