Alpha Dac 1. Upgrade path?

Perhaps someone knows of an article that I can access?

Very early DAC1 cannot be upgraded to DAC2.
Check your serial number with Berkeley.

I don't own one. It's my "curiosity" about isolation? and clocking? improvements. New knowledge interests me and creates questions and ideas. Fun

Having owned both the DAC1 and DAC2 I wouldn't call it an upgrade exactly but rather a slight change in presentation. IMO: The DAC2 is a slightly kinder gentler version of the DAC1 but the 2 loses a few of the 1s strengths.
Some might prefer the 1 while others might prefer the 2. Your system could also influence a preference. For me it was a toss-up.
Sorry I don't know the technical details of the differences.

Thanks for your user experience Rja. It seems I've heard similar comments before. It encourages me to consider an economical, older Alpha Dac 1. It would likely be a great step up from the Lexicon RT20 I presently use.