Recensies & Reviews

March 2020. Last year on the Xfi I walked into a room where a few B & W’s from the 800 series were playing. However, I could not find the amplifier or was that the small box in the middle? It turned out to be this box, the COBALT DA from True-Blue Box, barely 3 kilos, made in Holland. This class D amplifier kept intriguing me and in the end I decided to get the COBALT DA on a trial basis to compare it with my conservative class A / B amplifier, the Atoll 100. Contacted Vintage Audio Repair and a few weeks later I took it home without any obligation. I quickly connected the COBALT DA to my, also made in Holland, Millon Phantom S speakers and gained the first experience. What I immediately noticed was the analytical ability of the amplifier. You experience a wider stereo sound image, so you are more in the music than before. Then I went to listen to specific songs and compared them to the Atoll 100. Where the Atoll often buzzes the deep electronic basses of To Care Like You by James Blake, the COBALT DA does this clearly better with more punch. Due to the strong analytical character of the COBALT DA, complicated pieces of music such as Level Five by King Crimson come out of the speakers with more detail. Then played the super audio recording of the CD Touch by Yello. I heard the song Till Tomorrow very differently than with the Atoll. George Michael’s CD Older with it’s many sounds / instruments also had to believe it: here too many details without getting tiring. Of course the MM phono output also had to be tested with my Nagaoka MP-200 cartridge. What applies to the CD also applies to the vinyl: tighter, more details, more beautiful stereo image. Music experience is a personal, emotional experience. With the COBALT DA my experience has certainly become more beautiful. And I think it will be very difficult to find a better product than the COBALT DA which simply offers very good quality for its price. Completely free of charge, you will receive the customer-friendly and excellent service from Esther and Abbe from Vintage Audio Repair!

Ivo de Bruijn


A hi-fi guru once taught me: “Only believe your own ears”. As an eternal Quad fan, I let my trusty 22 / II tube set participate in the shoot-out with the Cobalt with great confidence. And while it felt like some sort of adultery or betrayal, I had to admit the Class D amp caught up with the tubes. Not only different, but much more refined and with great ease the music comes to me. I was hit by it. And that is what I am looking for in an amplifier. So believe your own ears and listen. It is also very cozy and the passion and expertise is everywhere.

Gerard Mooij


I have been in possession of the T-BB Cobalt DA amplifier for three months and I am very satisfied with it. First of all, the size and easy operation. It is a compact all-in-one amplifier. Actually, it is a power dac with a class D as the final amplification. There are 5 inputs, 3 digital, 1 analog and 1 phono input. (I will come back to that later) First of all, the sound quality of the digital inputs, these are due to the special chip from Axign and the loop that is incorporated here, the sound quality is phenomenally analog, without digital edges. The sound and stereo image is spacious, wide and deep with a lot of detail, it gives a three-dimensional representation with a very controlled and tight layer, this applies to all layers in the music. Voices and instruments are shown in the right place and are absolutely not smeared at high volume. The sound image is behind, in front of and next to the speakers.
This also applies to the analog input. The phono stage is of a very high quality and intended for elements with a high output voltage.
If you use a low output element there are a few things to keep in mind. Elements with an output of 0.3 mv to 0.5 mv, use a step-up transformer with a ratio of 1: 10, this because of the 10 mv input voltage of the amplifier, for elements of o.25 mv and lower, a step up transformer of 1:20 can be used, the reproduction of lp is impressive, you are really involved in the music. This is a product with a lot of quality for little money. For more information and technical questions I refer you to the website or contact Esther Engelen or Abbe de Groot.

Rene Nooyer