Berkeley Audio Design Alpha DAC Reference Series 2

[Echolane]

Anybody know anything about the Berkeley Audio Design Alpha DAC Reference Series 2?? Especially, how does it sound?! Will it mate up nicely with my Quad ESL-63 electrostatic Speakers?
I just bought one used for a fraction of the original price. It was one of those things where I had to decide stat or I’d lose the opportunity. Did I make the right decision?? It supposedly has the same DAC as the famous Pacific Microsonics Two which influenced my decision.

 

[manisandher]

It supposedly has the same DAC as the famous Pacific Microsonics Two which influenced my decision.

No, it doesn't - sorry. When I opened my Pacific Microsonics Model Two up, it had a pair of what looked like Ultra Analog D20400A R2R chips (though they were labelled Pacific Microsonics). Berkeley uses off-the-shelf AD1955 delta-sigma chips.

The Pacific Microsonics Model Two is heralded as a great sounding DAC. IMO, it's a far better ADC than it is a DAC - my PCM1704-based DAC sounds substantially better.

As to whether you made the right decision, well, if you like the sound...

Mani.

 

[morricab]

No, it doesn't - sorry. When I opened my Pacific Microsonics Model Two up, it had a pair of what looked like Ultra Analog D20400A R2R chips (though they were labelled Pacific Microsonics). Berkeley uses off-the-shelf AD1955 delta-sigma chips.

The Pacific Microsonics Model Two is heralded as a great sounding DAC. IMO, it's a far better ADC than it is a DAC - my PCM1704-based DAC sounds substantially better.

As to whether you made the right decision, well, if you like the sound...

Mani.

Interesting. The UltraAnalog UD20400 and A chips were outstanding...I have two dacs with them inside and I really like the way they deliver the music. I also have a BBPCM63 based DAC that i like a bit better simply because it has a good tube output stage and the other DACs had lesser SS output stages. None of them are up to the AC Kassandra though, which uses the even simpler AD1865N (but a bunch of them) and a great tube output stage. The one that has the PCM63 chips was later replaced with the BB 1704 in the model lineup but I still preferred the sound of the PCM63 by a fair amount...go figure. However, the best chips of that era were undoubtably the PCM63 and 1704, AD1862 and 1865 and the UA D20400A...I would say they are still competitive today despite so called "progress".

 

[dan31]

A dac chip is only a part of the component. The power supply, board design and analog output stage are great. You have a great dac. Enjoy it!!

Over time you will grow to appreciate it more or look for something different.

 

[Echolane]

Thanks for comments all. I have to confess I’m a little snowed by all the references to different DAC chips as I’m not very experienced at talking chips. Or DACs either for that matter. It’ll be replacing my first and only DAC, an Audio Alchemy DDP-1 which I’ve been quite happy with, but the Berkeley should be in a whole new league for me.

I won’t have the Berkeley in my possession until late next week at the earliest. I hope it will fit well with my system, which is another important variable in making choices of gear. I’ve recently had my Quad ESL-63 speakers rebuilt and I’ve a fairly nice French made tube amp, an Audiomat Prelude Reference MK II. My music of choice is opera and classical. Fingers crossed that it fits with my music preferences and my system.

Janet

 

[ack]

Enjoy the new DAC but be well aware that it changes character dramatically with different volume settings, and a range between 50 and 58 is where you want to be, with the latter sounding very euphonic. This behavior is also one of the reasons that it just can’t drive amps directly, because you end up using volume settings around 40 or so which makes for thin sound.

 

[kswanson27]

I have to disagree. I'm running a Berkeley Alpha DAC 2/MQA > Boulder 2060 > Magico S3 MkII's at 35-45 normally on the Berkeley and the sound is anything but thin. As far as changing with volume settings, well the music gets louder when I increase the volume and softer when I lower it.

 

[Echolane]

have to disagree. I'm running a Berkeley Alpha DAC 2/MQA > Boulder 2060 > Magico S3 MkII's at 35-45 normally on the Berkeley and the sound is anything but thin. As far as changing with volume settings, well the music gets louder when I increase the volume and softer when I lower it.

If you have a Berkeley Alpha DAC Reference Series Two with an outstanding amp like the Boulder 2060, I’m going to assume it must sound pretty good. I am definitely eager to give mine a listen. Even though my amp doesn’t compare.

 

[kswanson27]

If you have a Berkeley Alpha DAC Reference Series Two with an outstanding amp like the Boulder 2060, I’m going to assume it must sound pretty good. I am definitely eager to give mine a listen. Even though my amp doesn’t compare.

My Berkeley is an Alpha DAC 2/MQA, not a reference series. Still, I stand by what I said in my earlier post. Let us know how your system sounds when you get the DAC.

 

[Echolane]

Enjoy the new DAC but be well aware that it changes character dramatically with different volume settings, and a range between 50 and 58 is where you want to be, with the latter sounding very euphonic. This behavior is also one of the reasons that it just can’t drive amps directly, because you end up using volume settings around 40 or so which makes for thin sound.

I’m confused about a couple of things. Why should it change character with different volume settings? If it’s not a defect, it sounds like an odd engineering decision.

What do you mean when you say “you can’t drive amps directly”. My audio chain for the Berkeley DAC will look like this and I assume this is the typical for a DAC:
Naim Streamer > DAC > Integrated amp > Speakers.

 

[ack]

You have an integrated amp with a preamp section, and I am talking about power amplifiers, which is a typical debate about whether DACs can properly drive such amps directly. Just about everyone I know has eventually plugged in a preamp in between. The problem is finding a transparent-enough preamp.

The sonic behavior with the volume control is apparently in every Berkeley, from mine to the new Ref3 I heard last week. You will see in the manual that they recommend a specific value when driving a preamp, for best results. I had this discussion for the upmteenth time with the dealer again before the Ref3 audition, which sounded very euphonic at 58, with clear resonaces and exaggerations with strings. I have personally settled for 50-51 in my system, after years of investigation and modifications. Local friends here have also been able to tell sonic differences between two volume settings just 0.1 apart, and so have I, but it may also depend on each system's resolution. My impression is that intrinsic speed is also affected by volume setting. On the upside, it has been proven time and time again that Berkeley's claim that their digital volume control does not affect resolution is true.

BTW, I felt the improvement in the Ref3 is rather substantial over the Ref1, don't know about the Ref2

 

[Echolane]

BTW, I felt the improvement in the Ref3 is rather substantial over the Ref1, don't know about the Ref2

That’s an intriguing comment. It always surprises me that there is so much room for improvement. I was under the impression that DAC development was more mature.

I was not in a position to review this DAC Prior to purchase, so I am counting on this reviewer from The Audible Difference accurately representing the unpgrade between Series One and Series Two “I was skeptical that the Series 2 could offer a significant sonic upgrade considering the performance of the original. How much room was left for improvement? A lot, it turns out.” And then, “it didn’t take long to hear the startling advances wrought by the Series 2.”

It would surprise me even more if they have achieved an equal jump in improvement between Series Two and Three. If so, it would probably be wise to delay an investment in these expensive DACs until the technical improvements are less pronounced.

 

[ack]

FWIW, I never thought much of the Ref1; had at home too, was OK.

 

[kswanson27]

Don't agree with ack on the SQ differences with volume settings on Berkeley DACs but I do agree with him on the Ref 1. Had one at home and really strained to hear a difference between it and the Alpha DAC 2. Also had a Ref 2 here briefly and there was an improvement over the Alpha 2--not huge certainly but audible. You bought a very good DAC.

 

[ack]

Yes, could not hear any difference between my then-unmodified Alpha and the Ref1 either.

Regarding fine volume control adjustments, there are plenty of posts on this site, and here's one of them https://whatsbestforum.com/threads/acks-system-end-of-round-1.2740/page-33#post-505511

I was listening to lots of music that I know well to test how transients were, and as expected, they were generally excellent. I did notice a slightly synthetic edge to violin sound on my Kremer CD of Bach partitas for solo violin, but this problem was well addressed by lowering the digital volume from 53.1 to 53.0 (yes, that's right, you didn't misread). Ack tried that again after I suggested that the tone of the Janaki Trio on LP was superior to the tone on CD. The very slight change also helped timbral resolution on strings which, even though it was very good by most standards, had not been what it could be in my view -- don't you just love digital volume controls, especially this one. In any case, I still think that the digital is not quite what it could be in terms of timbral resolution, and obvious alternatives at this point might be the Schiit Yggdrasil DAC (which I also have) or the Spectral 4000SV CD player, both of which have fixed output rather than a digital volume control.

also https://whatsbestforum.com/threads/acks-system-end-of-round-1.2740/page-33#post-503178

I am finding out that certain midrange notes are then ringing, depending on the volume level. So the hunt for a perfect setting has become an obsession. Whereas I was running it at 53.5 (ringing) to 54.0 (noticeable IMD) before, I have now settled on 53.0 and things are so smooth, and believe it or not, a tiny bit more dynamic. It's simply fascinating to witness the change in character, and all the more reason I hate digital volume controls - they really show their ugly face in a high resolution system. Ugh!

 

[kswanson27]

Yes, could not hear any difference between my Alpha and the Ref1 either.

Regarding fine volume control adjustments, there are plenty of posts on this site, and here's one of them https://whatsbestforum.com/threads/acks-system-end-of-round-1.2740/page-33#post-505511



also https://whatsbestforum.com/threads/acks-system-end-of-round-1.2740/page-33#post-503178

I'm skeptical to say the least. I find it hard to believe someone can hear a difference with a 1/10 DB change. However once I get work out of the way today I'll give it a go. I'll use some familiar music and go for the highest volume setting I can get away with, probably 45 or a little higher, and report back.

 

[ack]

So it's not 0.1 "dB" change as you said - we don't know what the 0.1 level adjustment in the DAC translates to dB.

There are a lot of things going on in that DAC series with the volume control; some of these I interpret as classic manifestations of IMD (classic bass softening in some cases, classic treble edginess in others), others, there is just simple tonal balance shifts (bass cutoff or treble exaggeration). I experienced this tonal shift today with heavy bass drums between 51.0 (thin) and 52.0 (heavier but somewhat softer), and I have now settled at 51.5, for a very well rounded, tight and powerful bass without treble edginess. But I have modified my DAC so much that this level of fine detail may not exist in the Ref series, but the effects of the volume control in general are quite evident in these DACs in a high-resolution system, which is what had me start modifying in the first place.

If you are to experiment, pay particular attention to IMD effects - quite audible to me with string and piano - much like how one would listen for SRA/VTA changes in vinyl analog. It does involve training one's ear to focus properly, but once you achieve that, the effects are unmistakable.

 

[Mdp632]

@ack makes me wonder why (Berkeley )don‘t include the ability their customers to disable the pre amp function built into their dac.

 

[kswanson27]

I'd like to believe I have a fairly high resolution system--it sounds great to me-- and all my gear is stock and will almost certainly stay that way. As my sig shows I'm not running a preamp and that may well effect the sound although no one yet can give me any electrical reasons why that would be the case. I'll follow your suggestions and focus my listening accordingly.

 

[kswanson27]

So it's not 0.1 "dB" change as you said - we don't know what the 0.1 level adjustment in the DAC translates to dB.

There are a lot of things going on in that DAC series with the volume control; some of these I interpret as classic manifestations of IMD (classic bass softening in some cases, classic treble edginess in others), others, there is just simple tonal balance shifts (bass cutoff or treble exaggeration). I experienced this tonal shift today with heavy bass drums between 51.0 (thin) and 52.0 (heavier but somewhat softer), and I have now settled at 51.5, for a very well rounded, tight and powerful bass without treble edginess. But I have modified my DAC so much that this level of fine detail may not exist in the Ref series, but the effects of the volume control in general are quite evident in these DACs in a high-resolution system, which is what had me start modifying in the first place.

If you are to experiment, pay particular attention to IMD effects - quite audible to me with string and piano - much like how one would listen for SRA/VTA changes in vinyl analog. It does involve training one's ear to focus properly, but once you achieve that, the effects are unmistakable.

According to the Alpha DAC 2 specs on Berkeley"s website the volume control is in .1 dB increments.