I was speaking to Geoff Merrigan of Tellurium Q a while ago and he made a passing comment about how occasionally reviewers  can speak about hifi components as if they are talking about fine wines and wax a little too lyrical about it all…

And so without further a do here’s my review of the £4800 Tellurium Q Iridium power amplifier.

I have a “favourite” red wine, it’s Chateau Siaurac Lallande de Pomerol 2000. It’s not the most expensive of wines from Bordeaux, but I like it and when I fancy a bottle of good wine to appreciate, rather than to quaff, it’s my go to bottle. Now I know there are more expensive bottles of wine out there and I know there are ‘better’ wines to be had – I also know there are more everyday wines and I drink these on an almost daily basis.

Now you may be asking why I’m banging on about bottles of wine when I’m supposed to be reviewing an amplifier. Well,Iridium_1_small the point I’m making is that I have a standard – a reference by which I judge all other bottles of wine. I can sit down, taste a bottle of wine and say immediately that this is either better or worse than my reference. The same is true of hifi. It’s quite simple to evaluate a piece of equipment in ones own home and make a subjective decision on which equipment out performs (or otherwise), to your ears, your reference.

Like Chateau Siaurac my reference amplifier is my go to piece of kit by which I judge all comers. It’s not the most expensive of amplifiers but nor is it the cheapest. I’m happy with it – it’s my day to day listen and I’ve had no desire to change it. When an amplifier comes in for review I go through the same review process and then plug the reference amp back in. Sometimes an amp may sit on the rack for a month or so but when it’s gone I’m always happy to return to my trusty reference.

The Iridium by Tellurium Q is a single ended class A amplifier that gives out a not massive 18 Watts per channel into 8ohms (the same as my 300B PSE amp actually). It’s a heavy beast weighing in at around 21Kg but it also looks quite elegant on the top of the rack. Now, I say the top of the rack because being class A the top of this amp gets very hot indeed (the heatsinks are on the inside of the casing) and I’d be unsure about putting it in a situation with anything directly on top of it.

The Iridium is a dual mono design where each channel is effectively isolated from the other and uses a mixture of power MOS FETs and large power semiconductors. Each channel has its own dedicated torroidal transformer and rectifier bulk capacitors for smoothing.

It’s a handsome beast if, like me, you like that kind of thing. Basically what you get is a solid aluminium front plate with a single on off button and three LEDs indicating the amps status – they are red when the amp is off but connected to the mains and turn green when the amp is switched on. Above the LEDs are the letters TQ in black and at the bottom left an unobtrusive “Iridium”. Nice and understated for what is quite a big unit. It looks purposeful and certainly no frills – it’s a power amp after all!

On the back of the amp there are left and right RCA inputs, a pair of high quality binding posts that will accept spades, OLYMPUS DIGITAL CAMERAbananas or bare wires and the power socket.

I fed the Iridium directly with my Valve Audio Devices – DAC and used the DAC’s variable gain to control volume. Transports for the duration of the review were the Pioneer DV737 and a netbook running Foobar 2000 with WASAPI output. Speakers used were the hORNS Mummy which are the speakers I use daily plus the Alacrity Audio Caterthuns.

Switching on the Iridium results in a not inconsiderable thump through the loudspeakers and at first this was more than a little disconcerting. You get used to this and I doubt very much whether it is loud enough to cause any kind of damage even to the most sensitive of loudspeakers (the Mummys are 95db). After that there is nothing – and by that I mean that until you actually press play there is no audible sound from the amplifier at all through the loudspeakers. I spoke to Colin Wonfor the designer about this and he came back with the following comment.           

“All single ended amplifiers have the same issue when running on mains which is hum due to ripple on the power supply. To solve this the Tellurium Q design uses very large value capacitors to remove most of the ripple causing the hum and regulate the main DC down to our working voltage and current limit control. We also use the Hum Busting circuit designs to further eradicate the issue. More than that, the regulated power supply has been designed to be able to track the amplifier, giving it the power that it requires at any one time to be able to follow spiky dynamics.”

So now you know!

The first music I put to the newly plumbed in Iridium was some Neil Young (I forget which album as I wasn’t making notes) whilst waiting for dinner guests to arrive and the first thing that became really obvious was the vocal. It was more than easy to (almost impossible not to in fact) visualise the movement of Neil Young’s mouth whilst singing. I sat on the edge of the coffee table and really connected immediately with the music and on a very emotional level. I didn’t even notice our guests car pull up outside until they banged on the front door I was so drawn into the music. Judging by first impressions this was going to be a very interesting few weeks with the Iridium.

Some tunes

Let me say straight way that I’ve listened to hours and hours of music using the Iridium and worked through loads of albums that have not had an airing for ages. Most of the time I didn’t bother making notes I was just happy to listen to the music. However, convention dictates that I must try and convey some of the characteristics of the amp using some tunes you may or may not be familiar with. I’ve picked out a handful of tunes from different genres to try and approach this in a balanced way. The first four are using the 95db, 4 Ohm Mummys and the last one is using the 88db, 8Ohm Caterthuns.

First up is the excellent “OK” by Talvin Singh. It’s a drum and bass album that is very much flavoured with Indian spices. The opening pads on “Traveller” were lush and huge whilst the hats and other percussive noises were crisp and perfectly in place in the mix… and they remained there. I wrote the word “pinpoint” in my notes and this is what I got from the amp.

Bass notes go deep on this album and with the Iridium in the system it sounded great – deep and controlled.

The overall effect was one of balance with nothing being allowed to dominate in the mix. Soundstage seemed to be much deeper and wider than I’m used to.

Now this is not a live album, it’s an electronic album created in the studio with the producer plonked at the desk in between a pair of monitors so there’s no point me harping on about “space around instruments” and what not, but from a mix point of view everything just seems to sit correctly in its position in the mix and never wanders.

The Silent Poets “Sun” is in a nice, easy-listening, laid back hip hop style album and again the strings were “lush” but not overblown, samples were pinpoint (there’s that word again) in the mix and the voice on the Dumb Girl track were slightly forward in the mix. Again the bass starts and stops when it should, goes deep and again feels reaTQ£lly controlled.

I want to use the word fast when describing this amp, but in the terms of sound I’m well aware that that sounds a bit daft. However what I mean is that instruments, particularly percussion and bass start and stop immediately with nothing left hanging around for longer than it should.

If you don’t know Tryo they are a favourite amongst the French and play a wide variety of music in an acoustic reggae style with great vocal harmonies. The album “Mamagubida” is a great introduction to their music and I heartily recommend it. Now, French isn’t my first language (some may say English isn’t) and at times this album is confusing from a vocal perspective. Here the vocal seems much more easy to follow and understand – clearer and sharper if that makes sense.

The tune “Pour un Flirt avec la Crise” certainly sounds like a live recording and the band may as well be on stage in front of you. Toe tappingly good! I found it incredibly easy (again) to visualize the musicians on the stage and again the effect is “fast”.

Kurt Elling “The Messenger” on the Blue Note label has a great opening track in the form of “Nature Boy” and here the vocal was rich and the tone of Ellings voice was portrayed perfectly. Pianos sound right as does everything else. There’s a lot going on in parts of this album but never once did the Iridium allow the music to degenerate into musical mush. It just seems to be in control without getting in the way.

As I’m typing this there’s my birthday gift from the wife and kids playing. It’s the Hawkwind Album “Warrior on the Edge of Time” and it sounds utterly brilliant! Menacing, monotonous and driving and I have NEVER heard it sound so good – and I’ve heard this album hundreds of times on loads of systems over the years!

The first album up using the standmount Caterthuns was Arrested Development “3 Years, 5 Months and 2 Days in the Life of”. The “People Everyday” track immediately conjured up a summer vibe and my head was nodding to the beat. The beat is a little “dirty” and this came through in spades adding to the feel of the track. Vocals were nice and clean and again everything in the right place in the mix. I thought the low output of the amp may struggle to fill the large room with the 88db speakers but I needn’t have worried as it drove the speakers well loud enough.


The most telling thing about the Iridium is that since it arrived it has remained in the system at all times, other than when other amps have come in for review, and the normal reference amp has sat on the shelf looking a little sorry for itself.

I’m aware that when trying to describe a piece of hifi equipment it can become very difficult not to come across as some kind of pompous wine snob by way of the words that are used, but trying to convey the sound and feeling you get from listening to a piece of equipment in plain and simple language can be tough and I’m sure I’m as guilty as most reviewers in reverting to type with this.

However, the Iridium to my ears and in my system just sounds and feels “right” and I highly commend it to anyone! It seems to be in control at all times but never gets in the way. I’d say it is as transparent an amp as I’ve heard and will highlight the strengths and weaknesses of equipment put before it in the chain. Feed it with good quality components and you will be rewarded. Feed it with crap and …well you know the rest.

It runs hot (It’s Single Ended Class A so it’s going to), it has an annoying pop when switched on but I can ignore these niggles completely as the sound the thing makes has made me rethink the reference in my system. That last sentence doesn’t seem to read right as the Iridium, to these ears, doesn’t really have its own sound  -it just reproduces what it’s fed with.

I can quite easily drink rough red wine on a day to day basis knowing that my preferred reference will be there on occasion to show me what I’m missing – I’m just not so sure I can do the same with this amplifier!

Is it worth much more than twice the asking price of my reference amp? Well it galls me to say it, but yes it is! Recommended 100 x 66px

Author -Stuart

And now Linette’s thoughts on the Tellurium Q Iridium

The TQ Iridium is a sneaky wee beastie (well, not exactly ‘wee’ but more on that later)

It arrived one weekend when we having a bit of a post Munich, ‘United Nations’ hifi fest at Hifi Pig Towers.  We were auditioning the Scherer Evince loudspeakers at the time and, in the interest of science and variety were trying different system combinations.

The Iridium skilfully maneuvered itself into our system, and, with all the cunning of a cuckoo chick, booted out its rival amplifiers and made itself at home in the nest.

It never left, just sat there gorging itself on music and power and growing bigger and fatter.

That was several weeks ago and it is still sat there and when I look at it now it just looks like it is meant to be Iridian_2_front_smallthere…and sounds it too.

Things can get a bit crazy here with lots of different kit passing through to entertain us..cables, decks, DACs, speakers etc etc So we try and got back to the reference system and try the new component with a sound we know because trying to listen to a new amp, new speakers and new cables all at the same time can just get too confusing.

No matter what goes through our system we revert back to a trusty 300B valve amp….so why exactly is the valve amp sat on a shelf covered in dust like an unused jar of Chinese 5 spice in the back of the kitchen cupboard, while the TQ amp squats happily in its place?

Because the Iridium really is THAT good.

You don’t know what you’ve got ‘til it’s gone

I can’t actually put my finger on what is so good about it, it just sounds right. 

Great for bass heavy dance music, just as good for acoustic stuff.

I could sit here and over analyse it but I just don’t think I need to…it may not make for a very long review but I will say it again, this amp sounds great!

It has done that stealth thing of getting into the system so that you only actually notice it when it isn’t there…because it doesn’t sound right without it.

It is almost like it has some kind of aural cloaking device that stops you hearing the amp so that you just hear the music…..just as it should be.

I’m really not looking forward to it going home.

I like big amps and I don’t know why

When the Iridium arrived I really didn’t think it would fit into the system.  For a start it is huge, standing out like a fat kid at an eating disorder clinic. 

It’s a great big boxy box but after a while you do start to realise it is beautiful, in a simple, uncluttered there-to-do-it’s-job kind of way.  If it was tarted up with loads of fripperies and bling it really would not look right, as it is, it looks like a power amp that means business.

I’m pretty sure that Colin of TQ is actually a wizard of some kind, after the ‘cable experience’ which completely Iridium_back_smallchanged my views on whether cables make a difference I was expecting good things from their electronics…but not this good.  TQ are a cable company, right? Well they make excellent cables but don’t be fooled, if the Iridium is anything to go by then they are damn fine makers of amplifiers too.

Try it, I dare you…TQ offer a 30 day moneyback guarantee if you buy direct from them.

I imagine after 30 days the last thing you will want to do with this amp is send it back.

And if you are trying to justify the expense to your other half, remember it is dual purpose, you can always sit round it with the kids and keep warm and toasty on a chilly night!

Obviously recommended and I guess I really should bite the bullet and recommend their cables too.Recommended 100 x 66px

Author -Linette

The amp has been sent to Dan and he had the following to say about the Iridium from Tellurium Q.

With an understated look, which makes it a statement in my eyes, the dormant chassis of the Iridium was placed into my system. I was taken by its stature on my rack and pleasantly surprised that the amp, although quite tall, is not very deep so can be accommodated comfortably on any rack and makes reaching around to the on/off switch or to plug in cables an ease.

I connected the SECA, which it is also known by, into my newly purchased and absolutely fantastic Totaldac d1 tube dac fed with my Squeezebox Touch and its newly acquired Paul Hynes SC5 power supply, along with my usual loom of Audioquest cables and some more new partners in crime – the DH Labs Red Wave Mains Cables.

On listening to the Iridium my first impressions were of pristine clarity  whilst retaining absolute naturalness. The bass which came out of my system was tight deep and dramatic with an openness to the midrange that would make the Ice Queen melt.

Sound staging was absolutely pin point, the emulation of notes from a deeper area in the soundstage that just spread and grew was astonishing, conveying all the presence and natural timbres in such a correct and palpable way.

The characteristic is clean yet never bright or harsh, rich but never warm to the point of being muddy or grainy, with a top end that simply sparkles without sheen.

An explosive charge of dynamics from my 90db Ayons slammed notes out which seemed massively larger than its rated 18wpc. I never noticed any volume issues between my 40wpc Emille and the SECA. Even high powered monoblocks which have graced my system didn’t outshine the Iridium’s current strong performance in grip.

As well as delivering large powerful passages with ease the SECA also conveys delicacy and emotion where necessary, even during more dramatic scenes, allowing those small spine tingling details to stand true.

The spatial awareness and sculptured three dimensional soundstage was eerie at times, projected, deep and wide with an absolutely convincing portrait of the subject tracks

Vocals were gorgeous, clean, controlled and full of body, the balance of the frequency response and wide bandwidth simply toned out each part of the music perfectly. Crisp highs, a fleshed out midrange and a bass kick that just simply reinforced every other area with a powerful and big robust nature.

Adding the ‘Black’ power cable to the Iridium improved its performance even further, by adding a good sprinkle more of that magical fairy dust that the amp must be made from. Everything stood prouder and taller, more confident and expressive without accentuating any part of its tone at all. Could I live with the Black? Oh my yes! Is it worth the added expense? Oh my, yes!

The Iridium for me is simply one of the finest transistor amps I have ever had the pleasure of listening to, a true SECA (Single Ended Class A) monster of an amp that does not in any way sound like a typical class A amp, at all. It’s far more open and transparent, cleaner and controlled, it just sound ‘right’ in every way imaginable.

Author – Dan












  1. Geoff Merrigan

    Thank you for the review.

    It is not surprising that you mention that you found vocals clearer and were better able to understand them. This is due in part to the fact that the Iridium has no phase angle shift through to 100KHz coupled with the using the Ultra Black speaker cable and interconnect which have also been designed to combat phase distortion you will have been listening to a system that is very phase distortion free which yourself and Linette independently both seem to have found gave incredible imagery and tonal balance.
    Best wishes

    Geoff Merrigan, Tellurium Q

  2. Impressive review- there must be many ultra-hi-fi owners and pundits who’d consider a SUB- £5k power amp ‘cheap’. I recall seeing a behemoth on the floor of an audio dealer’s shop costing over £100k [or so he said].

    Anyway, this is a solid state device that outputs 2x18w?? SECA explains this, due to the excessive heat produced indicating very low electrical efficiency?

    As is obvious I’m a novice; getting back to audio after 40 yrs of family commitments, when I can better afford
    something of reasonable quality, which is basically a *£5k system:-

    Roksan 5/2 Nima/ Chorus Silver
    Odyssy Kartago
    Magnepan MMG Super
    Black Mamba cables

    Can you suggest better matches, or point out mis-matches? An amp such as yours would be no use in such a system even if I could afford it, right?

    * this can be achieved buying on line or perhaps some used components…

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