I am using a La Scala DAC, and am delighted with it. I am not, however, a tube expert.
FWIW, the reviewer Christian Punter, who hold the Aqua DACs in high regard, had this to say on the thread topic:
As the manufacturer has specially selected the tubes, it is not recommended to experiment with them but if you wanted to, you could. In this case, my experiment was fueled by a recent change in tube complement by the manufacturer. Up until recently, the La Scala was delivered with Telefunken ECC81 tubes but now they started using the Genalex Gold Lion ECC81. The DAC was delivered with the Genalex tubes installed but Marco was so kind to also include a pair of Telefunkens for me to compare.
Well, on this subject I can be very brief: the Genalex tubes are an easy and utter improvement over the Telefunken tubes. The new ones are much more refined and agile as well as more energetic, yet sweeter and airier and very liquid. On top of this, they provide wider soundstaging and clearer positioning of images therein. Yup, this is a very easy call, no ifs, and buts: the new tubes are simply much better.
Note that both tubes mentioned are fundamentally the same (ECC81). In my case, my satisfaction with the sound in stock form (Genalex Gold Lion) is more than high enough to suppress any desire to roll tubes.
For those interested, here’s a link to Punter’s La Scala review, from which the above excerpt was taken:
La Scala
