October 2012


Volume 6 No. 3
Valves Galore
Some of the components seem to use valves as a token gesture.
Not so this NVO Cypriot phono stage, which has no fewer than 22!
(And yes; it does get hot)
Review By Chris Bryant

     A totally new name to me, Novo is sold in the UK by Emporium, a small collective of high end retailers that seem to be handling a wide selection of imported brands these days, including the valve-equipped Lektor CD player we reviewed and recommended in HIFICRITIC Vol5 No1.

Also valve based, Novo’s £4,850 SPA-II is a new valve phono amplifier capable of handling both low (moving-coil, MC) and high output (moving magnet, MM) cartridges, and is built on an epic scale, with no fewer than twenty two (!) valves and an outboard power supply.

Designed by Andreas Hadjiminas and made in Cyprus, the casework is black painted steel with aluminium back and front panels (the latter thicker, brushed and anodised), and sits on large, slim, soft rubber feet. However, the finish and structure could use some detail improvement to match the best competition: when I pushed the ‘Mono’ button, for example, it sprang forward a couple of inches, not quite falling out. Having said that, it went back without problem and continued to work, but such simple fought to be sorted.

Two high current 6C45P single triodes per channel are used at the front end, so this device has an excellent low noise characteristic. The RIAA curve, using both passive and active equalisation, has two 12AX7 stages with 12AU7 cathode follower output. There are two valve regulators per channel and it has a star grounding system. All passive parts have been carefully selected for accuracy and quality, but no exotic audiophile passive parts are evident save for some polystyrene capacitors.

The separate power supply unit is built into a steel and aluminium chassis with a plain brushed anodized aluminium front panel. Mains input is via a fused IEC socket, switched by on/off relay signals from the amplifier. A sizeable 300VA multi-tap toroidal transformer feeds each channel separately, via various bridge rectifiers, associated capacitors and regulators. Regulated DC supplies the valve heaters.

Amplifier front panel controls are minimal: three buttons provide MM/MC gain selection, mono and on/off. The back panel has both single-ended and balanced outputs; the latter requires termination if single-ended mode is used (suitable XLR plugs with resistors are provided). Inputs and single-ended outputs have gold-plated phono sockets. The top plate is generously slotted for good ventilation, which is certainly necessary as the valves produce considerable heat. The lid also gets hot – rather too hot to touch after a while – which might well offend some CE regulation these days. Computer style cables with multi-pin D plugs link the power supply and the amplifier.

Lab Report
The distortion at 0.5V output is a respectable - 73dB across the audio frequency spectrum but the intermodulation distortion component of twin 19/20kHz tones was a high -19dB (11%) on MC. However, the audio spectrum is generally clean elsewhere. Channel balance is an acceptable 0.2dB at 1kHz but a variation above 10kHz is seen, the left channel peaking +0.8dB at 35kHz before falling quickly, whereas the right channel falls away rapidly above 20kHz with no peak evident – some minor component mismatch between channels perhaps? The signal-to-noise ratio on both MC and MM settings is good, the latter some 5dB quieter at -72dB CCIR and A-Weighted. Sensitivities are sensibly set at 6mV for MM and 0.39mV for MC. Input overload margins are high at all frequencies and output impedance measures a reasonable 60 Ohms; the MC input impedance is 120 Ohms.

Sound Quality
On first listening this phono stage seems to exude power. It can sound exciting and energetic making my regular head amp sound a little limp and bland. However, after a short while, once the inner sense of sonic equilibrium has been established there are obviously some other factors at play. The SPA-II has a spotlit, fragmenting effect (which I’ll explain later). Timing is not top-class, and a lack of nuance was noted when a lot is going on. The bass lacks the desired neutrality and tends to deliver more of a knocking sound than it ought: it lacks subtlety and does not deal with pitch change well.

At times the sound seems to share more of a PA than a conventional hi-fi character, but the live and lively atmosphere created may well acquire supporters. The midrange can sound a tad hard and forced, but it’s inconsistent, at times really interesting, bringing out parts of the mix that aren’t normally audible. And yet it’s not particularly transparent or lucid, and tends to emphasise bits of the midrange at the expense of neutrality and so it can sound rather coloured. On the right music it can be very seductive, because of the way it can alter the music itself: a siren’s song that draws the listener in only to wreck hopes upon the jagged rocks of reality.

Electric guitar in particular can appear highlighted, the individual parts detailed and exciting, but the hard extra edginess of it all eventually brings on listening fatigue and you begin to tire of the added excitement. There is also an extra-metallic ring in the treble when certain notes are struck.

From all who heard it, the most critical comments always concerned the fragmented timing. On occasion it seems to pull the threads of the music together very competently. On another piece it slices through them and leaves the sound with so little coherence that the band might as well have split up into separate rooms.

The soundstage lacks the depth available from the very best, is even two-dimensional at times, and focus can also become somewhat problematic. It can get a little old fashioned, sometimes creating a ‘wall of sound’, seemingly attempting to assault the listener with violent audio projectiles. It can be immensely intriguing with seductive, punchy dynamics and for this some will love it, but the overall performance may never truly satisfy some erudite listeners.

On choral material, and particularly with a solo soprano voice, it can sound forward and forced which I found tiring and simply unsatisfactory. Rock music can be excessively enthusiastic and a bit too bright, with overbearing percussion and edgy vocals. While this may certainly be exciting, such excitement can be exhausting.

Piano sounds coloured in the upper register but very beguiling lower down, in the few octaves around middle C. Metronomic bass with randomly timed midrange brings an unexpected new slant to some jazz pieces – interesting but wrong. The energy balance can make orchestral strings strident, the result of which is often a changed perspective which alters the shape and structure of the soundstage, resulting in a reduction in depth and allure. Probably the best word to describe it is boisterous: it’s chaotically over animated and not always totally in control.

If you could extract some of its vitality and inner essence and sprinkle it on a more transparent and better timed implementation, the combination would take some beating, as this is a really good attempt at a phono stage. With a little more development it could stand comparison with the best, but in its present state more refinement is needed to take it into the top category. Switching back to a rather better balanced reference resulted in distinct disappointment as the reference lacked the ‘live effect’. Although I was grateful for its balance, timing, staging and natural consistent tonal quality that returned to my system, I still miss the sense of energy the NVO delivers.

Conclusions
Build quality aside, this phono amplifier needs more work in order to satisfy critical listeners. It may give the punchy sound that some need to obtain an exciting ‘quick fix’ from high energy music, for it delivers upfront high-level detail aplenty. When at one with the music it’s playing, it shines brightly and becomes very seductive; on the very next track, however, I might find myself turning it down to escape its eccentricities. The NVO’s ability to put so much life into some performances might mean that it’s just what you’re looking for. But I’d advise auditioning at length before buying, as it’s just too exuberant and coloured for some tastes (including my own). I want its ‘get up and go’, but want this to be tempered with more control and consistency. It tempts and tantalises, and this might be enough for some tastes, but it can sometimes confuse and confound while hinting at greatness.

Reference Components
Cartridges: Koetsu Red
Signature, Koetsu Vermilion,
Dynavector 17D3 Karat,
Ortofon Rondo Blue. Phono
Amplifiers: Naim Superline,
Vacuum State JLTi PhonoPre.

Company Information
Emporium Hi-Fi
Voice: 01986 895929 or 01304 239419
www.EmporiumHiFi.com

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