The Vibex Reference Rhodium power extensionblock can be seen as a real reference. It is a benchmark against which other manufacturers can judge the quality of their extensionblocks. In this review we tested it thouroughly and compared it to an extensionblock from a new name in the game: CP-Audio.
This is a Spanish brand that quickly established a reputation for itself for building true reference-grade, highly neutral products. The thing is that no-one knows what is inside the extensionblocks. The company is extremely secretive about the ingredients used. All that's known is that the case is thick-walled cast-aluminium and that the contacts are rhodium-plated. That's it. Starwired? Solid core or litze conductors? The type of conductor: gold, silver, copper? Your guess is as good as mine. But in the end it comes down to listening and that's what we did.
On first listen it is clear quite quickly: this is a very well-behaved extensionblock. You cannot fault anything it does, it really is very neutral. The sound is very balanced from top to bottom, nothing sticks out. It is also pretty detailed and transparent althoug in these departments it can be bettered as I will outline below. Dynamics are well-served, neither restrained nore very wide and it has good speed and timing (PRAT). It is neither warm nor cool but it is slightly analytical through the midband where it can be a tad forward, dry and lean. There were audible differences between the 6 outlets in the way of a slightly more open and airy sound versus a more dark and solid sound but these were slight and are no real indication for deciding whether the wiring was parallel or starwired as even differences in lengths of wire will make for slight diferences in sound. All in all this block did not disappoint and did what it should: deliver clean power to six outlets without colouring or otherwise modifying the sound.
CP-Audio is a relatively new brand that strives to bring the absolute best, reference-class power products for less than reference-class prices. CP-Audio is a company that has actually been making power products for almost 10 years but thus far under no-name brands, sold via the Dutch webstore www.netkabels.nl.
I should mention straightaway that the brand CP-Audio is related to this site and its author. I realise that this may seem to appear as conflicting interests and that I will naturally proclaim "our own" products winners. But this is absolutely not the case. On hifi-advice.com I have always written independent and as-objective-as-possible reviews. If a cheaper product would outshine an established high end brand, I would just write this. It has never been about branding certain products over others and I am certainly not too proud not to admit when my product does less well than others.
Now let me explain a little bit about this extensionblock. The casing is cast-aluminium, like the Vibex, but a lot lighter, although there is damping internally as you can hear when tapping the bottom. The inlet is a 24k gold plated Furukawa-copper IeGO type and the outlets are Hifi Tuning 24k gold plated types. The wiring internally is something of a house-secret but what can be told is that it is a combination of pure silver and gold in starwiring configuration, not only for phase and neutral, but also for the ground.
Until now, for the obvious reasons outlined above, I have been reluctant to review related products like the Ultimate Clarity extensionblock under review here. But more and more friends who have heard the block tell me to let go of my principles, just publish it and let the world decide whether they trust the review or not. I guess that I am also just too enthusiastic about the results. Upon first hearing, even in isolation, I was amazed at what it was capable of. But when I compared it to the Vibex it became clear that I had to tell the world about it.
As soon as the Ultimate Clarity extensionblock is connected you are aware of its enormous resolution and absolute lack of grain. But it is presented with such fluidity and ease that it doesn't come across as analytical. The highs are extended and airy but never glassy or edgy, the midband is simply glorious: open and communicative but not in a dry or sterile manner but instead very natural and colourful. The bass is quick, agile and dynamic but it is a tad thin compared to some other extensionblocks. It is somewhat comparable to the Nordost bass. Some people find it too thin while others praise its rhythmic precision and lack of overhang. I'll let you be the judge here.
COMPARING VIBEX AND CP-AUDIO
Inevitably the two blocks will have to prove to one another what they're capable of. The interesting thing is that at first they seem pretty similar in overal balance. But before the song is halfway through you start to hear differences. For starters, the Vibex is strictly speaking more neutral but also less appealing and inviting. For all its extreme neutrality it also has a slightly cold way with harmonics, especially in the midband, which is a little forward and dry compared to the midband of the CP-Audio. Second thing you notice is the overall resolution. The Vibex is really very good but the CP-Audio just trumps it. It is at once more detailed and more relaxed. A strange sensation. Then the dynamics. Again the Vibex does well, being more dynamic than several standard extensionblocks but the CP-Audio is just a little more lively. The bass is the final comparison point where the Vibex does have more body but does away with this advantage by being less articulate and also a little slower. You could say that for this reason, PRAT is better with the CP-Audio.
When all has been said and done and you simply listen to the two blocks you start to hear at a more emotional level and the brain is throttled down somewhat. This is when you notice the underlying differences and it becomes clear that the Vibex may be more neutral but it is also more gray and ultimately less emotional. The CP-Audio is strictly speaking less neutral but all the more enjoyable for it. It is immediately appealing and draws you into the music with its highly detailed yet efforlessly smooth sound while, contradictory to common sense, as well as my experience thus far, the bass is very well timed and articulate and therefore, more entertaining.
These results weigh in even more if you take the prices into consideration: the Vibex is roughly twice the amount of the CP-Audio. For now.
I've listened to these extensionblocks in three systems thus far and every time the results are the same. Ultimately what we have here are two reference-class extensionblocks. Both exhibit a high neutrality and great detailing. The choice boils down to two whether you want absolute neutrality, even at the cost of some sparkle and swing or you want musicality even if that means a less than strictly neutral tonal balance. It is probably clear by now that I prefer the CP-Audio block for its higly open and airy, yet ultra-refined sound.
Call me a self-proclaimed winner all you want but I can assure you: you're missing out if you don't try the CP-Audio Ultimate Clarity extensionblock.
UPDATE MARCH 2011
The Ultimate range of extensionblock is sadly no longer available. Hifi-Tuning stopped producing the schuko outlets that were used in this block. Thus far no good substitutes have been found. All other outlets that were tried resulted in a wrong sound balance. Additionally, the blocks were very time-consuming which prompted CP-audio to look into producing an alternative extensionblock. Research and development is ongoing.