Mars SET Valve Amp

VITAL STATS

Connectivity	WiFi (2.4 GHz), 10/100 Ethernet
Specs	None supplied
Dimensions (HxWxD)	389 x 402 x 158 mm
Weight	13.5 kg

 

PRICE R54 900.00

SUPPLIED BY Mars Amps / 072 446 5072

WEBSITE www.marsamps.co.za / karel@marsamps.co.za

Here we go!

 

I like valve amps. I always have. I lived with a pair of monoblocks from the late great Gunter Steinhart that were hybrids but they ran hot and punched 100W a channel and they were made to work hard in their time with me. There is a romance of warm glowing valves producing power that cannot be erased from the channels of musical history and like vinyl they have many arguments both for and against. They are hard to make, and hence more expensive than mass produced circuit boards that can be easily inserted into a box and served with the latest and greatest software features – although I suppose the same argument might be made for my current NAD C298 power amp! Which is anything but.

The build on the amplifier is simple. Don’t drop it. I tossed the protective cover that came with it as I think the amp looks at its best when naked. Inputs and outputs could not be simpler. The two power meters are analogue and compared to digital offerings I am sorry to say it’s a No Contest. Digital offerings suck. These dancing needles are the schnizz.

Amplification being the dark art of ‘straight wire with gain’ has as many design philosophies as there are amplifiers. Valve audio tech is one within which many subsets exist. It is possible to build valve amps with substantial power (100w+) and you will see examples from Mars that do precisely this. But this amp has somewhat less power. Quite a lot less power if I’m honest.

It in fact has all of 8W.

Eight. Watts.

That’s it.

And by now you’re probably expecting me to was lyrical about how it makes up for this lack of power through being brilliant in that power delivery, how it ekes out the maximum from every milliwatt on hand, how it lays that power down in manners so sublime that you should just rush out and buy it immediately because it will improve your life in every meaningful way?

I often comment on LinkedIn about how many people frolic with pink unicorns in fields of cotton candy with rivers of creme soda flowing past the chocolate mountains in their delusional way of seeing the world they want to see it and not as it is. I shall do no such thing here. 8W is 8W and what that means is that no matter the way you slice and dice the stats you have 8W of delivery power to play with.  And if you have inefficient speakers it means that your listening levels are going to be lower.

That’s an end of it. Physics. It sucks.

Pure Class A watts however does mean that what levels of sound you do have present are generated continuously and with less distortion. Efficiency goes out of the window in other words but the trade off is a question of who cares about power efficiency when one wants sound quality?

I need to delve into SET (Single Ended Triode) valve design a little here and since the maker explains it best I am going to quote. I see no point in rewriting succinct information, especially when it is worth reading.

The term single-ended triode amplifier is mainly used for output stages of audio power amplifiers. The phrase directly heated triode single-ended triode amplifier (abbreviated to DHT SET) is used when directly heated triodes are used. 

The inspiration behind the design of the Mars SET is the discovery that music can be experienced satisfactorily, maybe even more deeply, at lower dB levels. It does imply the necessity/advantage of pairing high sensitivity speakers to the SET. Experience has shown that this issue is not clear cut. Some speakers with a sensitivity of below 94dB/watt might sound great (and loud enough), while some sensitive speakers may not do the amplifier justice.

From our first experience with tube stereo amplifiers in the late nineties, single ended amplifiers have stood out for their clarity and high frequency resolution, and especially their smooth transition from linear to overdrive conditions. The fact that you only need two output tubes, as apposed to four or eight for push-pull amplifiers, to keep your SET running, is also appealing.

If you listen to music all day, you’ll notice that the audio levels needed for clear music is way below the rated power capacity of most amplifiers. This “The First Watt is the most important” philosophy is most apparent with Single Ended amplifiers, especially with triodes famed for their low distortion.

At these lower power levels, you gain an effortless music experience, and hours of listening does not induce listening fatigue.

The bass response and general power capacity of the KT88, not to mention the plethora of options in current manufacture, makes it an ideal tube for a high power SET output stage. The cathodes are indirectly heated, which facilitates very low levels of noise/hum during operation. The well designed power supply filter section, utilising capacitor-inductor-capacitor (CLC), allows a wide sound stage to be experienced.

Right. All clear?

I listen to my music loud. It may not be all day but then I don’t know too many people with the time to listen to music all day long – if it’s background stuff I’d argue that you don’t necessarily need it to be all Class A. But aside from being belligerent and affronted by the lack of power of this thing I have to admit that the man has a point. My ESLs at 6 ohms and 91 dB sensitivity are not able to give me the volume that I am used to because they are utter bastards when it comes to power demands but importantly giving the Mars the full beans doesn’t stress the sonic picture. Not one iota. Until you’re getting to silly levels (and trying to ignite the curtains with the amp) the sonic picture presented remains comprehensively intact. What this means is that up until that point where you start to hear distortion and the amp is really struggling to keep up you’re going to be kept in audio bliss of pure Class A delivery. It’s straight wire with gain stuff. And, I think, this is the point. What a picture it is!

I got used to the relatively lower levels reasonably quickly. Your ears adjust as does your brain and whilst you do not need to sit on top of your speakers to hear anything when you are at maximum power you just need to accept that that’s where you are and listen. It doesn’t take long at all to realise that Class A delivers in spades and that even if the technology is a hundred years old it doesn’t matter. The job that it needs to do remains exactly the same. Amplify a signal without colouring it.

It is mandatory in these modern times to avoid usage of the words ‘lush’, ‘warm’, ‘rambuctious’ and ‘enveloping’ when attempting to put into words the listened experience of a valve powered amplifier. Mandatory!

Yet somehow I am drawn back to rambuctious. Uncontrollably exuberant is one way of putting the Mars’ approach to music. I am not saying that the amp is forward in any shape or form but it is not reserved or shy about the job at hand. There is an enthusiasm that belies the prejudice of a more laid back ‘traditional valve’ musicality that if I’m honest I might have been expecting. Nope. None of that makes an appearance here with the Mars delivering surprising punch and speed. The amp revels in quality material and in 2025 the quality of the analogue components is of course as high as one can get. Feed it well and you are rewarded with a performance that is true to source and I do think that with piano and strings the Mars is exceptional. I got a sense of timbre and harmonics from good recordings that cannot be denied. It is overwhelmingly pleasant and easy to listen to.

It comes from speed and timing. If you don’t have these in alignment on a recording you can lose detail rapidly. That can lead to a hardness in music and that in turn can lead to fatigue over time. Transients – those reverberations from a kick drum that settle down over time across the room are faithfully reproduced and the resultant sense of space that is created means that the Mars does well in a large room. I fed it a cross section of music from classic. light and heavy through to rock, light and heavy and it never put a foot wrong.

Whilst the amplifier does well in generating air between instruments and presenting a detailed sound stage, the deep bass notes that accompany presence in music are perhaps some what surprisingly, with the limited power on hand, presented with punch when needed. Deep low bass is handled as it should be, un-muddied and not over emphasized. Notes are allowed to fall off naturally with the amp appearing to conduct the speakers rather than directly controlling them (which of course it is). The result in my mind was the creation of musical texture that is carried right through the frequency spectrum, all the way up to the upper harmonics of cymbal clashes.

When you finally start to put it all together and get down to listening to music as it was intended a picture of what the amp can do emerges. This is not a shy or retiring approach to music where an amp relies on sheer brute force power to get the point across. No. This is an amp with confidence in its own abilities and it relies on sheer blunt force direct from signal accuracy. In other words it is fast, accurate and yet it manages in the process to imbue a sense of subtle musicality that irons out glare or harshness. It reminds me of days gone past where digital glare in early CD recordings was a thing and my feeling is that the Mars would simply smooth over such repugnance with the liquidity that is its very nature.

It IS ‘lush’ dammit. It is also luxurious. Thinks classy and also sassy – just try a saxophone solo with it and you’ll see exactly what I mean.

This is meaty stuff, from just 8W and this I think is the point, the result of Class A operation. The downside is that the amplifier is somewhat critical when it comes to your source material but maybe not as much as you might expect. It is present most obviously in music that will become muddied and lazy when the recording is less than well engineered. Garbage in means garbage out after all and if your favourite reference track is not up to standard the Mars will not save it. I do however think that it will try harder than most to paper over the shortfalls and there is a slight degree of forgiveness that I got from the amp that I don’t get from my solid state NAD C298. Do not however be fooled into thinking that this is a weakness because it is anything but.

Feed it (your) good stuff and the Mars will deliver in spades. Be prepared to lose hours at a time, but gain hours of happiness into your reservoir. It is that damned good.

William Kelly