Take a quick look at the SVP-2 pre-amp and you’ll probably conclude that it’s not much to look at, both a physical and an aesthetic judgment. Factor in the cost of ownership and your next conclusion will be that it’s over-priced too. Indeed, this simple, lightweight box seems almost old fashioned in these days of CNCd casework on even the most affordable products, touch screen controls and multi-functional versatility. But that’s because it is. The Vacuum State designs represent a category, a type of product that has all but disappeared from hi-fi shops these days. This is a carefully honed and hand-crafted, purpose built unit, manufactured in tiny quantities with one aim and one aim alone; to sound as good as it possibly can. Of course, there are many that make such claims, and “hand-crafted” is an imprecise term. But in the case of Vacuum State we don’t just have to take the manufacturer’s word for it. In fact, we have words on words, extensive documentary evidence of the thinking and philosophy behind the SVP-2, published in the shape of designer Allen Wright’s Tube Pre-amp Cookbook, a mix of theory, schematics and kits for advanced DIY projects. And just like his cables (reviewed on page XX) he encourages an enquiring and experimental mindset and the free exchange of information. The SVP-2 is a commercial product, but it wears its purist credentials well and truly on its sleeve. So what has all this effort wrought?
Here we have a beautifully executed, minimalist circuit constructed from components selected, item by item, with an almost obsessive zeal. Nor is this just a regurgitation of established practice, gilded with a few little tweaks – just witness the company’s differential 300B mono-blocs if you want to see a novel circuit! Likewise the heavily shunt regulated, current sourced power supply used here. The SVP-2 is designed to deliver state of the art performance from a singleended (non differential) topology, employing a hybrid J-fet/6922 valve MC phono-stage along with an all-tube line section. The phono-sockets might look low-rent but have been selected specifically for their superior sonic performance, while you also have a choice of a variable resistor or stepped attenuator volume control. Components within the circuit are matched to exacting standards, particularly in the RIAA equalization, where any imbalance will be magnified dramatically.
But the design also recognizes that optimum performance depends on more than just the circuit and the components in it. System interfacing is critical to achieving the best possible sound, so the SVP-2 offers a range of adjustment that’s unusual except in the most sophisticated valve pre-amps these days. The phono-stage can be configured for MC (65dB of gain) or MM (50dB of gain) sensitivity, with parallel loading plugs to optimize input impedance. The standard value for both settings is 47kOhms, with 1 kOhm and 100 Ohm loading plugs supplied. Specific values are also available if necessary. The line stage can be adjusted to provide either 12 or 18dB of gain (raising both MM and MC sensitivity by a further 6dB), while an attenuated input (labeled D) reduces all those values by 12dB. All these settings are available on the rear panel, and in combination, they allow you to configure the gain profile of the unit to ideally match your system.
Whilst Vacuum State suggest that they’ve done everything they can to extract performance from the circuit, short of spending vastly more money, they also point out that external factors will affect performance, and are keen for users to try decent cables (including their own), power cords and equipment supports. Naturally, I wholeheartedly agree, but especially when it comes to isolation. The SVP-2’s casework is far from the most substantial I’ve come across. When cold, switching the input or volume control made the top-plate of the review sample ring, a reaction that’s reduced but not eliminated as the unit warms up. Whilst I’m assured that this isn’t typical, it does underline the potential importance of support and with that in mind I experimented with both supports and damping the lid, ending up with a combination of a finite-elemente Resonator on the front edge of the topplate and either Stillpoints or a Vertex kinibalu underneath. Of the supports, the most cost effective solution proved to be a trio of Stillpoints cones and risers, whose separation, dynamic definition and clarity of purpose really raised the SVP-2’s game.
Without the attention paid to support first impressions of the Vacuum State preamp can come across as a shade blurred and indistinct. But listen a little closer and the degree of instrumental texture and the tactile quality to the playing suggests otherwise. Sure enough, once you go to work on the casework, the dividends in transparency, focus and clarity are pretty dramatic. Always intimate and immediate, its rich and vivid mid-band underpinned by weighty, emphatic low frequencies, the Stillpoints rip away a haze between players, adding depth to the soundstage and focus to images, a lively crispness to dynamics that puts a spring in the music’s step, a sense of forward momentum when required, restraint when needed.