The DAC2.5 is middle of the current line up at Bel Canto Design. The unit is housed in a half-sized width unit. Excellent built quality and design. It looks the same as all the current Bel Canto components out there, so if you have seen it, they are basically the same design. In the front, there's only one big pushable rotary knob. A push-then-turn will select inputs, while a normal turn will change 24-bit digital volume levels. There's also a headphone jack in the front for you head-fi buffs. In the back there are selector for fix or variable output. Inputs are one AES/EBU, two Coax, one toslink, one USB input. Output are a set each of XLRs and RCAs. There's a neat feature which is an additional analog input, which are converted to digital with a high quality 24-bit/192khz ADC - the same kind that are used in recording studios. This analog input can be set to unity gain for HT purposes. All excellent quality connectors etc., impressive so far. The supplied plastic remote control is usable but feels rather cheap comparing to the unit itself. All other programs are being done using the remote such as input renaming and setting analog to HT bypass.
The DAC2.5 uses ultra accurate master clock, dual stage jitter rejection module, class-A output stage, advance low noise power supply. While it shares the same basic architecture with the top-of-the-line DAC3.5VB, the flagship substitutes an even more accurate clock, better discrete components, and a ST fiber optical input. The DAC3.5VB also subtracts the USB input and the power supply (requires you to use either an outboard low noise power unit, the LNS-1, which is basically the same as the one in the 2.5 or the Virtual Battery VBS-1 unit). If one want to connect a computer USB input to the 3.5, you have to get yourself Bel Canto's USB Light Link 24/96 or something like a M2tech Hiface EVO or Halide design bridge.My understanding is that the Digital Analog Conversion chip is dual-differential sigma-delta DAC from Burr-Brown operating full time at 24-bit 192khz. So this means that the incoming digital signal are over and up-sampled to 24-bit word length with slow roll-off digital filter. This DAC is on the modern end of the DAC spectrum where one end is delta-sigma hi-bit upsampling DAC while another (in-vogue) end being the "NOS" non-over-sampling, 16 or 20 bit vintage DAC chip interpretations. The volume operates in digital domain, but even at lowest listenable output levels, it is more than 16 bits. All my critical listening done at a level showing on screen as 75 (100 being max - 2v rms).
Listening
If I have to give one word describing the DAC2.5, it would be "clean". The background is exceptionally black, nothing there!. I put my ear next to the speakers and it is completely silent (I'm using balance XLR connections from DAC2.5 to the S300, that helps). i think this contributes much to its apparent ability to resolve low level details. If the DAC2.5 is this quiet, i couldn't imagine how much blacker the 3.5's black ground would be. Got to try some of these days.
The dynamics are excellent. Sharp transient came out from dead silent and the impact was all there in one of the most realistic recreation I have ever experienced. You do not have the "compression" effect of lesser DACs, the music expands. Tonality wise, its on the light and neutral side rather than thick with extreme analytical presentation, but never forward. Bass is sharp and quick with ample weight. I won't classify this as a warm sounding DAC, but it is never clinical or edgy - everything is so clean and clear. Highs seems to very extended and smooth. Soundstage is deep and layered but not particularly wide.
I used two methods of connection from my Mac mini (running the new Ayrewave music player at native bit rate) one is via toslink connection using Nuforce high quality toslink cable and another using USB. USB cable is the middle of the pack Audioquest Carbon model.
The different between the two methods of connection, believe it or not, is the height of the soundstage. USB connection has higher soundstage presentation. All other tonality are pretty much the same. I feel that toslink is slightly better with retrieving "air" around the instruments but can't really put my finger on it.
Comparisons
Like I said, I replaced before it, the Wadia 151. I did not do an A/B since it doesn't make any sense as I can not judge the 151 on its DAC alone. It is a powered DAC with 25 watt to powered the speakers directly. I'll write a review of the 151 in a separate post.
From my recollections, the Wadia is not as clean nor dynamic as the DAC2.5+S300 duo. Its soundstage is not as deep or as refined. The background are not as black. However, the Wadia is more "free flowing". Seems more relax at delivering music. Less analytical, I think. I would be happy living with either.
I also have on loan from a friend the Bel Canto DAC3 - the predecessor to the 3.5. Directly comparing the two with the DAC3 feeding single end input (S300 has a switch so you can flip back and forth) and match level for critical listening.
I was hard press to find any difference between the 2.5 and the 3 over toslink and coax inputs. But it is quite apparent that DAC3's USB input is not as good as the 2.5. There is a deterioration of sound quality when feeding it with USB. There are more sharp edges in some of the music and tend to push me to lower the volume down on some materials. However this is not night and day apparent, but it's there. So may be Bel Canto improves its USB receiver chip in the new line-up?
Conclusion
Bel Canto DAC2.5 is an excellent modern DAC. It is nearly faultless technically in conveying music. It is dynamic, clean, and neutral but its SPDIF coaxial inputs are superior to its USB interpretation, which is a let down given my specific needs. I'll keep looking but this one is a keeper for now.
Upcoming reviews:
Wadia 151 powerdac mini
Tranquility DAC Signature Edition
