Integrated Amplifiers

A machined plastic cover is supplied to keep straying hands and paws away from the valves, although I personally think the unit looks much more striking without it.

Top Trumps
For the listening, the Stereo ST30SE was connected to a pair of PMC Twenty5.24 loudspeakers [HFN May '17] and fed from a Naim CD5XS/Flatcap XS CD player/PSU combination. Listening to the amp in Triode mode, with the sensitivity set to 'High', I was delighted to hear the Stereo ST30SE pretty much put to rest the idea that single-ended tube amplifiers are all woolly and indistinct-sounding, by serving up a performance that simply sparkled. Not only was the top-end beautifully transparent but the amp seemed particularly adept at capturing the overall essence of a musical performance, portraying its complete message in a manner that was highly appealing.

Across the midband, instruments were believable and vocals were blessed with good levels of detail, although I did feel that Nicky Holland's voice while performing 'Nobody's Girl' from her 1997 album Sense And Sensuality on CD [Epic 487992 2] was a little huskier than I was used to.

There were other niggles with this track too. While the space between the loudspeakers was certainly well filled, there was a feeling that everything was a little lumped together, the result being that I had some trouble zeroing in on the particular elements that make up this recording. Then there was the fact that while the low-end was deep, it could sound a touch turgid at times.

On the upside, however, Holland's vocal was pleasingly centred between the loudspeakers and formed the heart of the overall performance against the gentle wash of keyboards and lilting piano. Clearly there was more to be discovered here and I decided it was time to start flicking some switches.

Digging Deep
Moving the sensitivity option to 'Low' helped boost the separation of instruments and vocals within the soundstage. Now Miss Holland appeared to have cleared her throat, stepped properly up to the mic and was projecting her voice into the room.

Because of this extra insight and clarity across the midband, there was a clearer feeling of where individual instruments sat in the mix, with the result that performances overall were better marshalled. What's more, this replaced the rather featureless 'whole' that had previously emanated from the loudspeakers, even if I still felt that the amplifier was not yet shining quite a bold enough spotlight on individual instruments.

Switching to Ultralinear mode, the Stereo ST30SE offered another step forward in sound quality. Yes, a little of the exquisite midband richness was lost compared to the Triode mode but, more importantly, there was now a far better sense that the bass belonged with the rest of the music. Ultimate detail was still a little short of the best but the amp still dug deep into 'Tilted' from Christine And The Queens' Chaleur Humaine CD [Because Music BEC5156406] and bass notes no longer outstayed their welcome. Instead there was a feeling that the Stereo ST30SE had joined the party and was getting its groove on.

Sweet Clarity
Moving on to experiment with both 'H' and 'L' gain options in Ultralinear mode showed they had a lesser effect than when used in Triode mode although the 'L' option was still preferable in my system. Indeed, I felt that the Ultralinear/Low gain mode showed the ST30SE at its best, the amp now able to generate a more realistic soundstage enabling me to either focus on particular instruments, or simply sit back and enjoy the performance as a whole. Now, listening to jazz singer Madeleine Peyroux's 'Dance Me To The End Of Love' from her album Careless Love [Rounder Records 0602498235836], it sounded is if the musicians had spread their chairs across the soundstage, the performance filling the space between my speakers convincingly. I detected that the double-bass still lacked that last ounce of real woody detail, but it felt like the Stereo ST30SE was finally pulling me right into the heart of the action.

However, whichever mode I selected, the one thing that made this amplifier such an enjoyable loyal companion was its unwavering treble performance. Throughout the switching, fiddling and evaluating, the top end remained blissfully open, sweet and detailed, having an almost see-through clarity that rewarded with whatever genre of music you cared to play.

Transparent to a tee, yet with never a hint of hardness or trace of an exaggerated sibilant, the presentation up top ensured that this is one single-ended amplifier that stands out from the crowd.

Hi-Fi News Verdict
There is sure to be something to please the majority of listeners in one of the Icon Audio Stereo 30SE's various modes. While its bass is not as surefooted as many other amplifiers at the price, it has a glorious transparency and always gives the sense that it is being faithful to the message of the melody at hand. If your musical taste hits its sweet spots, you will find that what it does well, it does very well indeed.