So it was a pleasant weekend. Just a few folks gathered together to listen to some good music. Well not only. It’s always about listening to something in particular and test it against something else. In this case one of the guys had brought his beloved CD player – the Unico CD Primo by Unison Research.
Well I had to say that I was rather suspicious about this testing. The first thing is that this CD player has a really good looking tube output stage. Having noticed that it was clear that this fellow has nothing to do with the neutral and transparent sound. However I kept my thoughts to me and we all sat down and listened.
The setup was quite simple. We had the CD Primo, Philips 880/DAX2, a DIY solid state amp and a pair of DIY big floorstanders build around Dynaudio loudspeakers. Sadly I wasn’t able to get my TDA1541A DAC with a modest clock upgrade for testing and comparison. Maybe this calls for a second listening session (and some more beers).
However the test had to be some sort of a neutral thing so we decided to make and improvised blind testing. Easy enough. One guy changing cables behind the rack which is by itself covered so that no one can see.
As I expected most of the listeners (but not all of them) referred the sound of the CD Primo, as it turned out after the listening sessions. My concerns were confirmed. And that is – most of the people would prefer a slightly colored (read – harmonic distortion) sound coming from the tube stage. So it’s the ever lasting question I guess – high fidelity of high pleasantness?
Now when it comes to the technical part of the things – the player was inspected and its actually nothing special. I wouldn’t put my money in such a product in a million years.
What we have inside is basically a cd-rom controller, a SPDIF receiver, DAC and two analog stages. Why two? Well TUBES of course! What is the point of designing a new topology to perform I/V filtering etc. The designers had done all of that with a usual, trivial op-amp topology. Its nothing more than the recommended schematic by Wolfson (WM8524 DAC). The tube stage is just put following the op-amp stage contributing to nothing. Well almost nothing. It surely gives the so called “warmth” to the sound I guess.