Every constructor of a device designed to amplify signals choses the technology, in which he will show his idea for sound, on a very early stage. This technology can be either tube based or solid state, there are also different topologies available, with a single ended class “A” amplification being the most noble one. Usually it is enough to mention, that a device operates in class “A”, to make it an object of desire for many audiophiles. And when an amplifier is constructed as SE, then it becomes elite, even before listening to it. 

However this class is also least ecological (please do not laugh, the EU can issue a directive prohibiting the manufacture and sales of such amplifiers any time), and for many potential buyers it has some aspects, that are hardly acceptable, and often regarded as shortcomings: starting with large current intake – mostly returned to the atmosphere in the form of heat and ending with low output power – what limits the choice of loudspeakers. Nevertheless even the biggest contesters, when they hear a well configured set using such an amplifier, do not deny the reason for its existence, and some are even so enchanted, that they try to use one too. Fortunately this way of amplification has also its diehard followers, fully convinced about their sonic advantages, so that we do not have to fear about them being still offered by various manufacturers. And knowing, that some distributors have such a pearl in their stock, we try to obtain it for testing, to be able to share our findings with you, our readers. But I should not talk about distributors and clients, so let us return to the main topic of today, the British power amplifier Tellurium Q, model Iridium 20, what means 18W in class “A” single ended. The distribution of this brand in our country is in the hands of the Wroclaw based HiFi Elements.

The hero of this test – Iridium 20, is quite big, with dimensions close to my reference power amplifier Reimyo KAP-777. The size of the enclosure is the result of the decision to hide inside the heat sinks, what makes is visually more appealing, but leads to some issues with cooling. Unfortunately you can quite easily notice this, as after about 3 hours of listening thermal protection kicked-in, switching off the unit, which then could not be powered on until completely cooled down. Initially I thought, that I have the temperature at home set too high, but my mother in law, who visited me, complained about freezing, so I discarded this reason. I have to mention this, as it happens, but for many people, who do not listen for prolonged periods of time, this may be a non-issue. Another small thing – not for all potential buyers, but maybe for some of them – is the knocking sound in the loudspeakers when powering the amp up. This is a result of minimizing the amount of components in the sound path. For hardcore audiophiles this has absolutely no meaning, it does not harm the speakers in any way, but it can scare away others. Unfortunately if it does, then those people will not have the opportunity to listen to good sound. Returning to design, the lead motive is simplicity. The fascia is made from a thick slab of aluminum, while the rest of the cabinet is made from sheet aluminum. Many ventilation holes were cut in it. The front is decorated with four lines milled near the top, with the company logo in the center. Below the logo there are three LED indicators, changing colors from red to green, indicating operational readiness of the unit and even lower the power switch is located. The back panel contains only the bare minimum of items necessary to operate the unit: single loudspeaker terminals, one set of RCA input sockets, main switch and an IEC power socket. Ascetic and refined, as expected from the British. But after some time the design becomes so familiar, that we cannot imagine a different version. Elegance above everything else. Fortunately there are still companies, that know how to achieve that.

It happens often, that I take devices coming to me for testing and bring them to the KAIM (Audiophile and Music Lover Club Warsaw). The room there is quite difficult in terms of acoustics (it amplifies bass). There I can hear, what the tested device can do in such conditions. Also the members of the club like to come and listen, their comments often help me in understanding the device better. That was also the case this time, as the noble setup of the tested power amplifier drew attention. The club members have heard a lot, so it is not easy to surprise them, but some things have extra priorities and the British amp became the star of the evening. I do not remember the whole playlist of the evening, but a substantial part of the session was done using a disc from the Café Zimmermann series, where the violin was the most prominent instrument. Unfortunately they did not sound as good as we had expected, and in confrontation with the AB integrated on duty in the club room (a DIY from one of the club members), they were plain irritating. All listeners, knowing about the power amp working in class A, waited to hear the magic that should be spread over the sound stage. To my surprise the Iridium 20 did not want to add any beauty to anything, going more in the direction of spectacular sound. It separated the instruments on the stage so completely, that some listeners thought, that it plays individual sounds, and not music. I did not go that far in my conclusions, but I did not feel the homogeneity of the music either. Taking into account the not so high output power of the amplifier, we can turn a blind eye to the slightly thickened bass, which, surprisingly, did not become the main aspect of the musical spectacle. That place was taken by the treble, which overly moved the tweeters. We listened to many more discs, but in all cases we had this touch of “over openness” present, and this led to the conclusion, that class A of the unit was not audible. Looking at that event from the perspective of a few days passing, when I listened to the tested product in my system, I think, I know where the problem was, and what the British constructors tried to achieve. Before coming to the main description, I will just mention the keyword – line preamplifier. In the club we used a solid state device, which combined with the open presentation of the Tellurium Q, resulted in the sound becoming too analytical. On the other hand, the tube preamplifier I use in my system showed exactly, where the British constructors wanted to go. This whole paragraph is a classical example, that components should be combined in a synergistic way, as the test at my home, with two different loudspeakers, showed another, much better, side of the amplifier.

Like mentioned before, the test of the British power amp was conducted using two different loudspeakers, which were absolutely distant in terms of their construction. My reference Bravo are full band speakers, while the second pair, were small bookshelf speakers with a big heart for playing, the model Art from the Austrian company Trenner & Friedl. Those little speakers fared so well with my reference system, that I did not want to miss the opportunity to drive them with a class A single ended amplifier. In both cases (Bravo and Art) the Iridium 20 generated w very nicely layered sound stage, extended to the sides and in depth, with a spectacular impression of a black background. In the club, with the solid state preamplifier, this was a bit artificial, but with a tube in the sound path, things became much more convincing. I still felt the domination of the upper frequencies, but it was by far not so invasive. It meant here just lots of information backed with a warm midrange and quite fleshy lower frequencies. I noted this effect with both sets of loudspeakers, with the obvious correction taken into account for the capabilities of the given set. Taking into account the limited power of the unit, it sounded better with the small Austrians, than with my dragons. The stand mount speakers gained more, and the condensation of the lower octaves resulted in a fleshy, while readable bass, which I could not achieve with my Japanese speakers (but please remember the context of capabilities vs effect). The increase of the mass of the sound with a lively treble, from such small loudspeakers, could be very appealing for many potential buyers, and if such a set would be available in some audio salons, then it could be a bestseller for people with smaller listening rooms. A big sound from small loudspeakers, with a very noble presentation, is not something you encounter often. I heard a lot of such propositions from other manufacturers, but usually this was artificial, especially in the low frequency range, and that was clearly audible. In my proposition, the effect of pumping up the bass is not so prominent, and it allows to be happy with the final effect, without any side effect, especially in the form of averaging the information in the bass area, and such thing is just art. In addition we get an open, and very informative treble, with a midrange completing the whole, and we can forget about buying a new system for a long, long time.

With both loudspeaker setups I listened to a very similar playlist, and every time, all the mentioned aspects were confirmed. The tube in the sound path allowed to play even the most demanding discs, showcasing the freedom and openness of the reproduced music, without any issues in the whole sound spectrum. What I am trying to do here, is to show, how the tested amplifier works in two different loudspeaker setups, which I had at home, and one more setup from the club. I think, that this should give you some extra insight in the capabilities of the British amplifier, but to make the things more complete, I will mention a few words about the way and quality the virtual sound stage is setup. I left that till the end, as it was flawless and is completely adequate to the position and price of the amp in the company catalog. The width and depth did not allow for any critic, even in the KAIM club. Maybe it was not a spectacle, like it can be presented by for example the Harbeth 40.1, but every musician had its own part of the space created behind the loudspeakers. Knowing about the limitations of the British amp in terms of output power, I decided also to try some more demanding repertoire, especially in that aspect. For this I used the album Khmer, from Nils Petter Molvaer, with nice synthetic sound backed with a trumpet. But the trumpet is not the most important thing on this disc, it is the artificial bass, reaching very low. Many times on my audiophile way I learned, that not only pure power counts here, so when the Tellurium Q was fed with the bass heavy music and I must say, that it informed me well about what the artist decided to tell us with his music, without any distortion. Of course, when the volume knob went too much to the right, in no longer acceptable levels, a slight pant appeared, but who would like to power a concert with a quite weak amplifier. This is a product for a demanding music lover, and not for a stadium sound level lover.

Trying to combine the above into a certain whole, I want to turn your attention to the fact, that such an amplifier, class A single ended, requires some preparations. Wanting to buy it must be a thought through decision, because it will not play good with random gear, and the buyer should know its limitations. For some people this can mean, that an amplifier like this will fall from the list of potential candidates, for others it will be the start of a way to a musical nirvana. Anyway, the TQ power amplifier is a very interesting proposition, and I would for sure not scrap it from the “to listen” list just for the reason mentioned – being picky about the rest of the system. In my case you can see, that it is not so hard to get to a consensus. And I used only products I had at hand, while a potential buyer has an unlimited amount of listening combinations, and for sure can find a satisfying one. I can only say, that the more time we spend searching for the combination, the longer we will stay with it listening. And having to choose the right components does not mean, that the amplifier is not constructed well, but it is just a one-of-a-kind device, which has such requirements as a starting point. I encourage you to try it out, to listen to a noble way of amplification, especially when paired with other noble components.

Jacek Pazio    

The system used in the test, a complete set of Combak Corporation.

 Electronics Reimyo:
- Separate DAC + CD player: CDT - 777 + DAP - 999 EX
- Tube preamp: CAT - 777 MK II
- Solid state power amp: KAP - 777
Speakers: Bravo Consequence +
Power cables: Harmonix X-DC-350M2R Improved Version
Speaker Cables: Harmonix HS 101-EXQ (mid-high section); Harmonix HS-101 SLC (bass section)
IC RCA Harmonix HS 101-GP
Digital IC: Harmonix HS 102
Table: Rogoz Audio
Accessories: Antivibration stand for the power amp by Harmonix TU-505EX MK2; Harmonix Enacom improved for AC 100-240V; Harmonix Tuning Room Mini Disk RFA-80i; 
 Analog stage:
- Turntable:
drive: Dr. Feickert Analogue "Twin"
arm: SME V
cartridge:: Dynavector XX-2 MKII, London AEC C91E “POD”
- Phonostage: RCM „THERIAA”
- Amplifier: KAIM Club - Ugoda
- kolumny: Trenner&Friedl ART; KAIM Club -  Clockwork

Opinion 2

For as far as I can remember, every product I had for testing, became a reason to make a research about the people behind it. And it was for sure not to detect any financial interests of those people, or connections between them and other players on the audio market, but about learning their point of view, the way they perceive music and sound, what ideals they might have, and what is their reference. This time it was different, because I met the, quite bold for the audio market, expressions of Geoff Merrigan, and only later I could host a product he created – the Tellurium Q Iridium.

But let us go back to Geoff. When somebody introduces cables to the market, and the electronics, then he should know, how thin the ice, he is stepping on, is. But when such a person knows, how easily you can be judged as being a charlatan, and then officially states that “numbers (technical data) do not help in understanding the sound (of cables)”, it cannot be perceived differently than being a conscious provocation and stirring up the pool. But taking into account, that Tellurium is present on the market for some time now, and there are no signs, that it would be leaving it soon, we can dismiss the thesis, that such stir is done only for financial reasons – to make hype around the brand, earn quickly and change the branch. So that what is left means, that Tellurium wants to move against the stream, break stereotypes and use their own, proprietary solutions. And that is exactly the case, the gentlemen having a lot of engineering knowledge, Mr. Colin Wonfor and Geoff Merrigan, decided that technical correctness as measured, is not the goal for them, but only a starting point for reproducing the beauty of music as good as possible.

In opposition to widely used solid state push-pull amplifier setups, the tested Tellurium Q Iridium 20 (in the second version) represents an uncompromised and minimalistic niche of single ended. A nishe, where quality is more important than quantity, and the topology of the circuit, using only one amplifying element (a Mosfet transistor) becomes almost identical with a typical SET (Single Ended Triode). As a result we get, or we should get, a sublime sound of a single triode, with dominant even harmonics, so liked by the human ear. In addition, to simplify and have as little influence on the signal as possible, the constructors resigned from using capacitors, and the output power is not very conventional either – we have 18W @ 8Ω and only 9W @ 4Ω. All those orthodox solutions were enclosed in a quite big, but surprisingly handy chassis. The front panel is made from a thick slab of brushed aluminum, with only a purple power switch and two milled grooves near the top decorating it. There is also a modes two letter logo of the manufacturer and three LED indicators of the mode the amplifier is in. The back is as minimalistic as the front and houses only single loudspeaker terminals, main power switch located above the IEC power socket and singular RCA inputs. The rest of the back plate is covered by ventilation holes.

Going over to the listening section, we should, in a way, separate from each other the usability and sound domains, but with the Iridium it will not be easy, as the power amplifier does not allow us to forget about it. It is not enough, that it serves us with a powerful click in the speakers when powered up (no capacitors and coils in the sound path), but during listening you should take into account the temperature and air circulation in the listening room. Strange? Not really – the power amplifier gets hot as a boiling kettle, and when we have about 20 degrees Celsius in the room, and the amp is paired with not so easy to drive speakers, then … we will not listen longer than about three hours. If you say now, that no one with a common sense will buy it, I will agree completely with you. But nobody ever proved, that audiophiles are part of normal people with a common sense. Usually they are condemned, excommunicated at least once a day. So when you feel rejected, disinterred or the Last Mohican of good sound, and you do not have the word compromise in your vocabulary, then the Tellurium Q Iridium 20 should immediately become a part of your listening list. Now we decided, that I am not fully normal, I started the listening session, and while I did not want to end it too quickly, I created a small draft in the listening room. This allowed me to listen for about 6-8 hours, what shows clearly, that it is achievable, if you want.

Now ad rem. Taking into account the quite low declared output power of the amplifier, first tests were planned using the small bookshelf speakers Trenner&Friedl Art. Jacek added to this telling me about how well this combination sounded, what could become a savior, as my own loudspeakers are very open themselves, and that combination could become a bit traumatic. The problem is, that I tried the same thing with the tested lately Leben 300F, and finally I stayed with my Gauder. So I decided to try first the setup with the Arcona, and when something would go wrong, then I would switch over to the Art. So I connected the Iridium to my loudspeakers, switched the Ayon into the mode with variable output (talking about being minimalistic) and turned the whole set on. A welcome shot in the speakers officially confirmed the start of the listening session. If I would not know the declared output power of the Tellurium, I would guess it around 30W, or even 60W, taking into account my 4Ω speakers, which would be equal with the power declared by Accuphase E-600. But even having this knowledge I listened, and I listened, and I could not believe my ears. To cut things short I could describe the sound as surprisingly big and incredibly energetic. You could almost feel unlimited power reserves, which were not there, when looking at the table with technical data. Although the bass was not fully controlled at the lowest registers, and frankly speaking, did not even try to, the micro and macro-dynamics did not suffer from that. In addition the edges of the sound spectrum were absolutely readable and far from becoming veiled, the treble enchanted with crispness and crystal clarity. No granulation, no warming, no ethereal fog. In contrary, clear, like the cleanest diamond, treble, able to cut air like a samurai sword. This made the differentiation of recordings reach unparalleled heights, what allowed to discern the good and bad recorded discs after a few first notes, but on the other hand, it also split the albums in those that were nice to listen to, and those, which would occupy their spots on the shelves forever. When we make the initial selection and sit down in our listening chair, then we will stay there for a long time, believe me. The resolution combined with velvety smooth homogeneity, know from classy SET amplifiers, makes each and every album to become an event, a mystery, that we live through with the musicians and vocalists. The invisible barrier, that limits the flow of emotions, disappears somewhere. It is not present here. Everything is for touching, and the way the space is recreated only amplifies the effect. Let us take the phenomenal album of Herbie Hancock “Possibilities” with “A Song for You”, where Christina Aguilera sings, as an example. On one hand this is just a simple compilation album, which should bring the artist a multitude of new fans, not acquainted with more orthodox jazz climates, and bring him additional funding, on the other hand, with the Tellurium, we hear a true love for playing. Stripped from plastic and glitter Aguilera sings in such a way, that we have shivers running up the back, and the rest of the musicians does their best, so that the whole would sound good not only on kitchen radios, but also on a good stereo system. All kinds of cymbals are surrounded with a black, velvety background, the vocal is palpable, strong and present, while the piano does not jump in front of other instruments, but gives the whole a master feeling.

It was not worse with a much more rough material. “In Session” by Albert King and Stevie Ray Vaughan stuns with pulsating feeling and freedom, with which those two guitarists lead their musical dialog. IN addition, the more I pushed the Iridium to hard work, the closer I got to what the sound engineer could hear, at least I thought that. There was no place for thinking, whether “they are here” or “I am there”, there was music, and only music. And a good one, so this was for sure no reason to complain. This was also a clear example, that even a less good recorded disc could pass the Tellurium test, because the recording shortcomings could not overwhelm the music, they were not able to castrate it from emotions. The roughness and harshness of the guitars were evident, indisputable and practically unanimous with electric blues, which both musicians played, and the amplifier did not even think about trying to smoothen or civilize that. It restrained itself to showing the truth, and this is a big art, in contrast to what you may think. With its natural freedom and intrinsic transparency the Iridium reminded me of the constructions from Lavardin, but in contrast to its French competitors, it went a step or two further on the quest for neutrality. The offered sound had a bigger volume, but also the speed of increase and decay of the transients was much better than in the mentioned constructions.

Switching over to the backup loudspeakers Trenner&Friedl Art freed the British amplifier from the need of taking care about lower frequencies, which could not be reproduced by the tiny speakers. Due to this the attention of the listeners could be concentrated on the above average space and precision of drawing of even the furthest sound planes. Despite the evident vivacity of the sound, there was no trace of offensiveness and only orthodox lovers of veiled, stereotypically tubey treble could be disappointed to the resolution, uncommon on this price level. However after hearing a few tracks, even they should have no problems in properly assessing the quality of the presented sound.

A dozen days spent with the unconventional power amplifier Tellurium Q Iridium 20 II confirmed the words of its constructor. The technical parameters are not able to tell much about the true sound. For the common sense, connecting a weak, and chimerical, amplifier to difficult to drive loudspeakers should mean an indisputable defeat and would be asking for trouble. But the listening session tells a completely different story. Even such irrational, at first sight, combinations can offer very good sound and make the distant concept of High-End become quite real. If you do not fear challenges, I warmly recommend to listen to this amplifier.

Marcin Olszewski

Distributor: HiFielements
Price: 6000 GBP

Technical details:
Output Power: 18 W/8 Ω ; 9 W/4 Ω
Frequency Response: 1,5 Hz – 60 kHz
Channel Separation: 102 dB
Noise: -90 dB
Distortion: 0,03%
Input Sensitivity: 1 V
Dimensions:  430x290x220 mm
Weight: 21 kg

System used in this test:
- CD/DAC: Ayon 1sc
- Digital source selector: Audio Authority 1177
- Network Music Player: Olive O2M; notebook Dell Inspiron 1764 + JRiver Media Center
- Turntable: Double synchronous motor Transrotor ZET 3 + 12"SME + Transrotor MC Merlo Reference + external power supply Transrotor Konstant M-1 Reference
- Phonostage: RCM Audio Sensor Prelude IC
- Integrated Amplifier: Electrocompaniet ECI 5; Accuphase E600; Leben CS-300F
- Speakers: Gauder Akustik Arcona 80 + spike extenders; Trenner&Friedl ART
- IC RCA: Antipodes Audio Katipo
- IC XLR: LessLoss Anchorwave; Organic Audio
- Digital IC: Fadel art DigiLitz; Harmonic Technology Cyberlink Copper; Apogee Wyde Eye; Monster Cable Interlink LightSpeed 200
- USB Cable: Wireworld Starlight; Goldenote Firenze Silver
- Speaker Cables: Organic Audio; Signal Projects Hydra
- Power Cables: Furutech FP-3TS762 / FI-28R / FI-E38R; Organic Audio Power
- Power distribution board: GigaWatt PF-2 + Furutech FP-3TS762 / FI-28R / FI-E38R
- Table: Rogoz Audio 4SM3
- Ethernet cables: Neyton CAT7+
- Accessories: Sevenrods Dust-caps; Furutech CF-080 Damping Ring; HighEndNovum PMR Premium; Albat Revolution Loudspeaker Chips; Acoustic Revive RAF-48H; Audio Philar Double Model

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