It’s easy to make a cheap valve amp today. It’s a lot harder to make one that’s cheap, good, and built on this side of the planet. And yet, somehow, Tsakiridis Devices manages to design and build quality valve amps that don’t cost a fortune, all from its base in Athens, Greece. The Aeolos, Aeolos Plus and now Aeolos Super Plus are currently the brand’s only integrated designs, with an additional seven different power amplifiers, two preamps, a phono stage, and three power conditioners elsewhere in the catalogue. All in the realm of ‘affordable high-end’.
The integrated amps are all Class AB designs, with four line inputs and the same ‘narrow, but chunky’ case. The principle difference between the Aeolos models is output tubes; the standard model sporting four EL34 pentodes, the Plus featuring KT88 or 6550s, and the Super Plus tested here sporting KT120s. In the process, this gives the amplifier a power boost to 60W over the Plus’ 45W and the standard version’s 35W per channel. Otherwise, everything remains identical. All three use four 12AT7 double-triodes in the preamplifier and gain stages.
Unlike many high-end for low-cost designs, concessions to economy are on the outside, rather than in circuit. The component quality is actually pretty high; there are few ‘name’ components in the circuit (the Alps potentiometer and the Chemicon caps are notable exceptions), but the Tsakiridis uses metal film resistors, high-quality polypropylene capacitors, porcelain tube bases and solid (Tsakiridis-matched) Tung-Sol tubes throughout. The chassis itself is in a powder grey with a contrasting black crackle finish; not exactly exotic, but strictly no-nonsense. The grey elements include the front panel, and the top cover for the transformers and the valve cage. Cleverly, the company also provides a neat extendable screwdriver with a magnetic tip that allows the user to reach into the otherwise-inaccessible regions of the valve case to insert or remove its screws. This might be a simple touch and nothing whatsoever to do with the performance of the amplifier, but it makes life a little less sweary at installation time. This attention to detail is, sadly …rare.
There’s one more concession to economy. Biasing the valves is an easy task, but not as easy as the automated systems now in place in more exotic equipment. It means you need to tangle with a multimeter and probes, in the way you always had to in the good ol’ days of audio. But with this, comes a little treat, albeit one that ‘is not recommended’ (but, curiously, mentioned) in the manual. The bias voltage and current has set recommendations for the type of output tube; turning the bias current up beyond that recommendation takes the amplifier out of Class AB1 and into pure Class A. This is ‘not recommended’ because it causes the valves to run hotter and shortens their working life. However, moving to pure Class A is tempting, because the sound is sweeter (and a lot of today’s valve amp makers push their amps into Class A by default). Just remember that turning up the bias means gently pushing the tubes out of their comfort zone; it does not mean cranking the bias so high you have four incandescent lamps burning bright (and burning out) before your very eyes.
The other options open to the listener are two sets of toggle switches that switch the amp between triode-strapped and full (ultralinear) pentode mode (triode is generally sweeter, but not as powerful) and a cut in global feedback (sort of ditto; lower feedback sounds a little more direct). As with all these concepts, the best answer is ‘experiment’. Try it with and without, depending on loudspeakers. Don’t expect profound changes though; it’s more subtle than that.
The one design hiccup in my opinion is the switches for adjusting feedback or changing bias are hidden behind the valve cage. As are the neat retro power meters. The cage hides all this from view, and the cage itself undermines the elegance of the overall design. I can’t suggest playing the amplifier without the cage for the same reason the manufacturer can’t recommend turning the bias up to put the amplifier in Class A. From a Euromentalist viewpoint, hiding the tubes behind a cage prevents them from escaping into the wild, burning, cutting, and electrocuting any life-forms that happen to be in the room at the time. Pragmatically, unless you have young kids, you might want to consider using the amplifier nude – the amp, not you.
We found the amplifier’s happy place was in a system comprising the excellent B.M.C. Audio BDCD1.1 and DAC1pre (in DAC mode) driving the Triangle Antal Anniversary also reviewed in this issue. Cables in this case were from the Chord Sarum TA range. At the time, I had no idea of the cost of the amplifier, but in assembling this particular package I made a system where the ancillary components all wound up costing more than the amplifier does (OK, so taken individually, runs of Sarum TA cost less than the amp, but as a complete system, they significantly exceed the cost of the Aeolos Super Plus).
The thing is, this shows I approached this in the manner you should approach all things audio; namely, with a completely open mind. More specifically, I approached it with a completely open mind as to price point. I had no idea whether this was a £2,000 amp or a £20,000 amp (it’s sometimes hard to tell). This means relying on gut feel as to its place in the world, and as such I felt the aforementioned system was ideal. It was only later, that I realised the amp was the cheapest part of the whole deal, which highlights just how good the Aeolos Super Plus really is. It more than stepped up to the task I had given it.
The amplifier has a lovely midrange, and ‘lovely’ is the best word that fits the job. It makes a sound that is warm, yet energetic, inviting, clear, and open. And lovely. It’s almost made for female vocals, whether solo voice or something like Elizabeth Fraser’s vocal on the excellent ‘Teardrop’ by Massive Attack [Mezzanine, Virgin]. Her voice has an intrinsic sense of beauty anyway, but the Aeolos Super Plus really brings that front and centre. You find yourself seeking out vocal and piano music as a result, because that midrange is so enticing.
This sweet midrange also extends to the treble, too. Overall, the sound is extremely civilised, as you might expect from a society that gave us Plato, Euclid, Sophocles, Homer, and Gerald Butler in his battle shorts. It’s a sound of great refinement, control, and honesty, which is at home with a wide variety of sounds. It is perhaps more geared away from the more ‘full-on’ aspects of music; there are amplifiers more comfy with pumping out Metallica – or for that matter, Mahler – at full tilt, but if you are in the market for some sophistication, whether in string quartet or jazz combo, the Aeolos Super Plus is a refined and elegant sounding performer. It carefully avoids the pitfalls of sounding ‘too’ valve like and warm, but makes its music sound so very sweet in the process.
There are a few sonic limitations that make their presence felt, however. I did find the bass was a little soft at times, more in line with classic Leak amplifier chassis than the more meaty, beaty, and beefy sound of, say, a McIntosh or Audio Research. This did vary very slightly from speaker to speaker, but was very comfortable with the Triangles. That being said, while the slight question over broad compatibility prevents the amp from achieving ‘panacea’ status, the fact remains that when suitably partnered, the Tsakiridis’ bass can take on a fast-paced, precise tonality, that gets you closer to the stickwork of Steve Gadd on Steely Dan’s ‘Aja’ from the album of the same name [MCA]. Gadd’s fills here are some of the most complex drum sounds you can hear on record, so to nail them so effectively is a tough call.
The Tsakiridis Devices Aeolos Super Plus does all the right things in the right places. It’s decidely European in design and build, without costing a fortune. It sounds like a good valve amp always did, before they became synonymous with ‘warm and rich’ sounds. And it’s unpretentious and doesn’t cost a fortune. Care is needed in matching it to speakers, but get it right and the sound is hard to beat. Especially at the price.
Push-pull, Class AB valve integrated amplifier
Tube complement: 4x 12AT7, 4x KT120
Power output: 60W per channel
Inputs: 4x RCA stereo line level
Outputs: 1x RCA tape loop, WBT speaker terminals
THD+N: 0.38% (1W at 1kHz)
Intermodulation distortion: 2.1% (60Hz/7kHz, @ 1W)
Frequency response: 20Hz-20kHz ±0.2dB
Signal to noise ratio: 85dB
Dimensions (WxHxD): 28.5x40x20cm
Manufactured by: Tsakiridis Devices
Distributed by: Flamingo Audio
Tel: +44(0)121 212 9288