All of my amplification is tube.
I switched the DAC to solid state and I also performed a recommended tweak of removing the tube when switching to solid state. In both cases, I preferred the tube option, but I replaced the stock tube with a Psvane 12AU7.
With the prices of American and European tubes escalating, I decided to give the Psvane a try at a more affordable price. The results were stunning, and I'm sure that other 12AU7 types will do very well. Many times, another tube will improve certain characteristics while giving up something else. I could not identify any particular loss with the Psvane. It does run a little hot, so I'm not sure of its life expectancy. I also have a variety of American 12AU7 tubes that I will try as well, but I don't hurry anything, so more fun later.
Here's what I reported back to Bill of Morningstar Audio, the distributor of the DAC Plus:
...With the tube (Psvane) notes are held longer, so there is more information in the air between the instruments/vocals. Without the tube notes are cut off shorter, so I find the overall sound less believable and more digital. The resulting illusion, to me, is less satisfying...
The DAC Plus is my first modern DAC, but I did a lot of listening at the shows in Denver and Montreal which I attended. I also own an old Theta DS Probasic III that was an excellent DAC of its time.
The way that the digital markets are constantly reinventing themselves, I did not want to make a huge investment in a DAC that would quickly turn into an outdated Theta, for example. I was blown-over by how good the DAC Plus sounded for $1,000.
I would suggest that you keep on asking your questions and get all the advice possible, as there is little hope for auditioning and comparing the tons of really fine boutique products that are out there.
