A modest investment that offers serious, long-term musical rewards…
By Roy Gregory
Whilst love at first sight is WAY too strong an expression, there are definitely audio products for which one has an immediate affinity. They simply look, seem or sound ‘right’ – actively inviting you to like them. With its simple, uncluttered and classy appearance, modest price and no-nonsense facilities, the Solen CV40-EL84 is just such a product.
For Anglophone audiophiles of a certain age, the name Solen should ring a few bells. It was associated in the ‘80s with a range of high-quality capacitors (although that was actually a different company). But at the same time, you might also recall the distinctive B-50 Tigre hybrid, integrated amp (marketed under the Ensemble name in the US), with its unusual triangular footprint. Meanwhile and although it might have been lost to (international) view, the company has been quietly beavering away, evolving its products and thinking through a number of integrated amplifier designs. The CV40-EL84 reviewed here represents their current, pure-analogue offering (there’s also a compact DAC, an integrated amp that includes a DAC and a tiny, standalone phono-stage). Although outwardly more conventional than the Tigre, the CV40 is, in many ways, just as off-beat. It’s just that in this case, the unusual elements are all inside…
Clad in an elegantly minimalist, if slightly bulky, brushed aluminium chassis, the Solen amplifier offers users a volume control, a quintet of single-ended line inputs and 40 Watts per channel. Measuring 450 x 380 x 135mm, the taller than average casework and heavily slotted top plate are necessary to accommodate the eight EL84 output tubes and the substantial power supply to drive them. An all-tube unit, there’s a 12AT7/ECC81 and a pair of ECC803S to drive the output stage.
Do the sums and you might be scratching your head. Normally, a push-pull pair of EL84s would be rated at around 10 Watts output – as in the legendary Leak Stereo 20. Two pairs, 20 Watts, no? Except that Solen are claiming 40 Watts from a quartet of EL84s, so what gives? Rather than the more popular Ultra-linear, push-pull configuration, Solen employs Circlotron output topology, which along with the parallel output pairs and regulated voltage rails apparently accounts for the 40 Watt claimed output. Developed in the 1950s by Electro Voice, it’s a topology that offers reliability and scalability, with the option to simply add additional output pairs. It allows for a low feedback circuit with low output impedance for better drive characteristics, at least in theory. As always, the proof of the audio pudding is in the listening.
Certain aspects of the circuit are clearly visible, like the dual mono power supply, built around a pair of solid power transformers (I’m always suspicious if a tube amp’s output transformers are larger than its power transformer) and the separate transformer for the switching logic and remote control. There are a number of other nice touches, like the damping rings fitted to the 12AT7, the provision of high-quality, chassis (rather than PCB) mounted sockets for two of the inputs – to handle critical sources – and a vertically mounted damping ‘bung’ fixed atop one corner of the left-channel output transformer, to stop the casework ringing. All in all, the CV40’s internals make for an impressive sight. Factor in the excellent fit and finish, surprisingly substantial 20kg/44lb weight (four serious transformers will do that for you), the paper spec and classy appearance and you’ve the makings of a genuinely intriguing proposition, especially at a price that tips only slightly the wrong side of 5,000€.
