Review of Berkley Audio's Alpha DAC Series 2 from The Absolute Sound...

[cmalak]

Berkeley Audio Alpha DAC Series 2 (TAS) | AVguide

[klipschfan]

No mention of the hum being eliminated that exists in the first model...

From computeraudiophile.com
Shortly after the Alpha DAC arrived I noticed a barely audible hum coming from the DAC. I immediately thought something was wrong so I contacted Michael Ritter seeking an answer. What Michael told me only solidified my belief that sound quality was the foremost concern of the Berkeley Audio team. He explained that the Alpha DAC has two totally separate power supplies for digital and analog, and two power transformers. The dual bobbin transformers used in the Alpha have very high isolation between the primary and secondary windings that provides maximum immunity from line noise. One side effect of this high isolation is a narrow area of magnetic field that causes the bottom of the DAC to hum a little bit. Berkeley Audio Design could have opted for an absolutely silent solution at the cost of sonic degradation. Listeners will be happy to know the hum is inaudible when listening to music even at the lowest volume the Alpha DAC is capable of producing, 0.1 dB.

[Elberoth]

Got myself a Berkeley Alpha 2 DAC to go with my Berkeley Alpha USB converter.

Some nude images, as I haven't seen many posted around:

PSU. Two separate transformers (probably one for digital and one for the anlog stage) feeding 6 voltage preregulators:


Main PCB. Programable SHARC chip (probably runs the custom digital filter alghoritms), AD 1955 DAC chipset and superb, Ultra Low Phase Noise clock made by Crystek, placed in the direct proximity of the DAC:




Top plate dampened with Dynamat Extreme pads:


All in all - another example of excellent digital audio engineering !

[junker]

Thanks for the great pics!

Definitely let us know what your impressions are vs. your other high-end USB DACs and what you think about the USB->DAC interconnect (BNC vs. AES and length), and as a digital pre-amp.

Did you have to order this from Switzerland as well?

P.S.: Did it come with the Dynamat, or did you add it? Do you think it is for vibration control or the acoustic reduction of transformer hum? I have some of their lightweight material under the carpet in the rear of my car after weight reduction efforts.

[cmalak]

Adam...thx for sharing and let us know what you think about the combo Berkley converter and DAC. I never heard the current version but auditioned the original Berkley Alpha DAC at Goodwins and my impression (this was 3 years ago) was very high resolution but still had a slight digital sheen to it and was not harmonically or rather tonally dense. RH's review of the BADA v.2 seems to suggest that tonal density has improved and that it is a more natural sounding unit. Would appreciate hearing your thoughts on it

[Elberoth]

Originally Posted by junker

P.S.: Did it come with the Dynamat, or did you add it?
Do you think it is for vibration control of the acoustic reduction of transformer hum? I have some of their lightweight material under the carpet in the rear of my car after weight reduction efforts.

Yes from Switzerland. The Dynamat was there when I opened it. This is the latest version with the new transformers. Haven't noticed any hum, but read that people complained about it on earlier units.

[Elberoth]

Originally Posted by cmalak

Adam...thx for sharing and let us know what you think about the combo Berkley converter and DAC. I never heard the current version but auditioned the original Berkley Alpha DAC at Goodwins and my impression (this was 3 years ago) was very high resolution but still had a slight digital sheen to it and was not harmonically or rather tonally dense. RH's review of the BADA v.2 seems to suggest that tonal density has improved and that it is a more natural sounding unit. Would appreciate hearing your thoughts on it

Did you hear it with the Berkeley Alpha USB ?

[cmalak]

Originally Posted by Elberoth

Did you hear it with the Berkeley Alpha USB ?

No. Before the USB converter came out. It was on v.1 of the DAC stand-alone.

[Elberoth]

Here is the older version - with the different transformers and lower quality clock:

[Elberoth]

With the new Ultra Low Phase Noise Crystek clock and Berkeley Alpha USB feeding it, there is absolutely no digital sheen or glare. This is one of the smoothest and most resolved DACs I've heard to date. Much more so than similarly priced Aesthetix Romulus, MSB AnalogDAC or Briscatti M1.

It is not as tonally dense as some (Romulus or Metronome C-5 springs to mind) so if that is sth you are looking for - look elswere.