I compared the Theta DS Pro Gen VA DAC and the Mark Levinson No 38 CD Player/DAC and the Theta was slightly better than the DAC portion of the No 38 player. The Theta DAC is an outstanding DAC. Don't get me wrong, the Levinson is outstanding also, but I liked the Theta over the No. 38 and the No. 38's DAC is a two level upgrade over the No. 36. The thing I really liked about the Mark Levinson CD Player DAC was that it had optical, Balanced and standard digital inputs. so you could use it as a DAC only. The only problem with the Theta was that the one I had did not have optical input, nor balanced. Just BNC, RCA. So depending on what inputs you desire, I would grab the Theta first, (unless optical or balanced inputs are important to you) and the Mark Levinson No. 38 second.
Also, the 380s is an upgrade to the 38 and is better. The transport in the 38/380s is very very good.
So, places still have the upgrade board for the 36 to upgrade them to the 38. I couldn't find any upgrade boards to upgrade the 38 to 380s.
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