Product: Silver Cube Phono Stage
Producer: Lehmann Audio - Germany
Approx.cost: 2500 Euro/$
Author: Geoff Husband - TNT France
Reviewed/built: February, 2003

Introduction

The name Lehmann hardly needs any introduction to readers of TNT. Lehmann's success in the world of phono stages has come about mainly thanks to exposure on the internet - positive exposure of course. Lehmann's name was made with the Black Cube, a mid price phono stage which embarrasses many high-end offerings. Its solid performance was bought by a combination of good circuit design and component choice. Its casework, as befits the name was a simple black box with a small offboard power supply.

With the success of the original Cube it was inevitable that calls would be made for Lehmann to make more upmarket stages and the SE, already reviewed here, was the answer with it's much bigger power supply.

But things move on and the temptation was to go for the upper end of the market with a "no-holds-barred" design with aesthetics more in line with an elevated price-tag. The result is currently making music here and is called the Silver Cube.

Construction

Calling the latest child of the line a "cube" is pushing it a bit. In fact the casework is a slim aluminium box, machined from solid - i.e. a big lump of alloy milled out! It's heavily anodised (silver of course) and so looks like a solid block rather than the usual box made from extrusions and bolted together. The front sports a small blue LED and nothing else - I think it looks gorgeous, if Lehmann could bring out a pre/DAC/transport and little monoblocks in this casing I'd buy them just for the cool factor :-)

Of course one reason the Silver Cube (hereafter SC) can be so slim is the monster offboard power supply. This is in the classic Lehmann black box and so has to tucked away to maintain cred.

The question is though, when you've made a giant killer like the BC SE how do you improve on it? Or do you just put it into a sexy box and double the price?

Well first Lehmann has put it in a (more than) sexy box and quadrupled the price :-) But then there's a lot more. The classic way of improving a good amplifier (and this is an amp after all) is to double up all the audio circuits and make it completely dual mono, then beef up the power supply. This is precisely what Lehmann has done with the SC. Everything is beautifully laid out in full (could be in two boxes) dual mono, and the Power supply is now a special 120 va toroid backed with all sorts of sexy tweeks, separate ultra fast recovery diodes for each seconday coil etc (OK you can tell I'm just reading this off the sales blurb but it must make sense to some of you :-). The components in the SC proper are also beefed up with designer bits - see the (slow to download) .pdf file on the Lehmann site for the gory details.

Round the back of the box there are four WBT phono sockets. There's also a set of DIP switches to allow for changes in loading and capacitance. The lowest resistive value was 80 ohms, higher than my DRT-1 likes, but a few minutes with a screwdriver exposes the guts and allow you to plug in any resistor you like, in the Dynavector's case 30 ohms. When you order the SC you can specify a custom resistor of your choice without extra cost which makes the SC one of the most flexible stages on the planet. It also has a set of two toggle switches per channel which can alter gain giving a maximum 66 dBl a gain of 2000x- enough even for such weedy cartridges as the Audionote IO and other weird exotics, of course something which requires very low noise levels.

Lastly underneath there are three feet which have their centres threaded for 6mm spikes - come on Lehmannn, these should be included!

Sound

OK now the important bit - does the SC remotely deliver the promise of a major upgrade on the Black Cube SE? No and sort of...

The "no" is simply explained. Like all Lehmann designs (and most most hi-end equipment) the SC has an extended burning in period. In my case it was left on continuously, and used as the main source, for 10 days (= 30 hours actually playing), after this time the sound switched from a bit harsh and clanky into something altogether more pallatable, though the sound continued to improve over the following weeks.

The "sort of" needs a little explaination so read on. Inevitably this review will concentrate on how the SC compares with the BC SE tested by Lucio (and myself in "twin" form). The latter is one of my favourite phono stages right up there with the very different, valve-like Slee Gold. Where the Gold has the edge (to my ears), is the almost total lack of the "grain" of a transistor stage, this coupled with a beguling musical flow and effortless delivery. Give it an edgy amp like the Loth-x Ji300b and it matches far better than the BC SE. Put on a more even amp and things don't seem so clear cut. The BC SE produces a more open view of events with a more overtly expansive soundstage - it's also a lot more flexible than the Gold (at a price). The SC takes all this one significant stage further whilst retaining the fast, open character of the BC SE

One way of looking at this is that a valve stage has a slight soft focus effect on music, leaving the flow intact but somehow missing the extreme colour, tugging at highs and lows. As the valve stage gets better the soft focus, and damping effect becomes less and less, the "image" coming into ever sharper focus. My own Audion valve pre is at this "sharp focus" point. Generally transistor stages are more analagous to digital photography. At the lower end you can get vivid, often overbright colour, but at the expense of considerable grain which can obscure fine detail as well as irritate. It can go unnoticed in a blurry budget set-up but it becoms painful in a better system especially with highly revealing speakers like my own Polaris. As the quality of the transistor stage improves this 'grain' becomes finer and finer until it is all but absent. In fact in this way I believe that though valve and transistor stages (and probably amps) come from different strengths, as they approach their ultimate expression they end up sounding more and more similar, in the same way that the latest 10+ megapixel cameras are approaching the ultimate resolution abilities of 35mm transparency film.

It's probably overdoing the analogy, but I like to think I'd have a fair job of spotting a valve stage in a pack of transistor one's. But when they get very, very good they sound just like that - GOOD. They trancend whatever technology they employ to just make you want to listen to music. I think I could just about spot the BC SE as a transistor stage, there's that hint of grain, very minor compared to others like the Dino but hinted at when the going gets tough and in a really revealing system, especially "middy" horns like mine.

In contrast the SC is a 20 megapixel camera. In my system it never once sounded anything but crystal clear but without a hint of grain. It retains the colour and speed of the BC SE but embues it with a superb level of refinement. My two favourite discs used to test for this are firstly Nancy Griffiths "The Last of the True Believers", on it her voice can sound like fingernails on a blackboard. OK it would be easy to slug the sound and get away with it that way but that would remove the edge and impact that should be there. Very, very few stages cope adequately with this and the SC is one of them that does - it also puts her in a bigger and more focussed soundstage than anything that's been here so far, though my Audion sounds a little bolder. The second disk is my treasured Harry James record, direct cut by Sheffield Labs. Here the ride cymbal is crystal clear with terrific energy, valve stages tend to sound as if the metal is slightly damped whereas the typical transitor stage tends to give it an unnatural "digital" quality. As it's a ride cymbal that means you get irritated about every 0.5 seconds which is one reason why I don't like most midprice/budget transistor stages, I can find several other similar examples in my collection. The SC gave it the required attack, ring and decay but never made me want to lift the stylus.

Moving on to something a little different, a quick spin of Level 42's first eponimous album shows the terrific speed in the bass with the "slap" acting as the leading purcussion in each piece. Bass seems to go deeeeep, but as nowadays I'm limited in this respect (unlike the old IPL days) I can't make too many definitive statements about the bottom octave.

Soundstaging was terrific, wider and especially deeper than the BC SE, partly down to better resolution of those very low level clues to the accoustic of a venue, be it real or artificial.

Ultimately the SC shares the open, clear presentation of it's cheaper sibling. But pick any single sonic caracteristic and you get the feeling that the SC has an edge, add all these "edges" together and you have something significant.

As far as compatability is concerned it was equally happy showing off the lush organic soundscape of the low-output MC Dynavector DRT-1 as it was the uncoloured, almost CD like prescision of the highish output Music Maker - each sounding so different and yet so "right". And here it should be mentioned that the Audion stage has the benefit of the Dynavector step-up amp to get the DRT-1 up to MM level and which costs a cool e2500 on its own - the SC ran unaided by such props and so was competing with a combination at well beyond its price.

Towards the end of the review period I had a new valve amp on test - e9,000 worth of high-tech (really!) EL34 integrated, The "Son of Pharao" (review in a fortnight). It didn't have a phono stage so the SC was pressed into action. Though the S.o.P. was an upgrade on my Audions, it was better in a similar way to the way the SC is an upgrade on the BC i.e. similar but slightly better in all areas The SC happily coped with the envolope being pushed back, and showed even more ability than before. I might add though that like it's forbears I suspect it would have found the Loth-X Ji300 just too pushy.

Conclusion

The Silver Cube is expensive, but by no means extravagantly priced compared to some. As far as I can hear, it offers as near faultless performance as makes no difference and can cope with any cartridge/preamp combo you care to throw at it. Some will buy it because it looks so good next to the Black Cube SE, but in fact it's a significant upgrade on that very worthy design.

The way I see it the Silver Cube is a "fit-and-forget" item, fit it and then forget the stage, no matter what cartridge you buy in future, and no matter how much you spend on the rest of your system it's going to cope admirably, at least up to the level of rest of the review system - e10,000 tt/arm/cart, e9,000 amp and e8,000 speakers, beyond that I can't (sadly) comment.

But going back to my comment "sort of" is the following... For most of us the Silver Cube will be just too good, the Black Cube SE will do the job and so the extra ability of the Silver Cube unutilised, it's the classic conundrum of the hi-fi/music addict, getting the best possible sound for a given price - if money is no object or you plan to move ever upwards in the future then the SC is worth the extra over the BC SE, if on the other hand your system is never going to really demand the very best in a phono stage then the Silver Cube will be wasted. At what point you hit that value judgement point is tough for me to explain. If your hi-fi cost you e1000 then I'm pretty safe in saying that the Silver Cube is a waste of money. Somewhere between the two extremes of this and the test system the Silver Cube comes into its own - your call...

After sending the review to Norbert Lehmann he did ask that I add the following - which is nice...

Postscript

I really would like to see you mention the name of my co-engineer Klaus Boehm in the review. I'm not sure if I gave you that information before. He is familiar with such things as impedance optimized copper traces in RF designs. He also is - and was to the project - a superb project supervisor, pcb-wizard and - last but not least - down to earth audiophile. Without him the Silver Cube simply wouldn't have happened. The zero-feedback output stage for example is basically his circuit as well as some major features in the power supply. It is a matter of honesty for me to credit those who contribute instead of pretending to be the one and only...