Jeff Rowlands Amp and Dac vs. VAC amp and DAC


Hello, I am new to this forum but I have a question. I am trying to pair an amp + DAC with my Wilson Sabrinas. I have listened to Jeff Rowlands integrated with the Aeris DAC. And the VAC Sigma integrated with the Aeris DAC. Price is a factor and so is space. Does the 625 need a pre-amp? Any suggestions or thoughts? 
rinpoche
To start - I am not one of them. I choose whatever combination I like. Purist would do either full tube or full solid state, more often full tube.
I don't know if you have considered this, but your new Rowland amp will need a good power cord, not that it will sound bad with the stock one. You don't have to match the power cord to your other cables, only to the component you are going to use it with. But let the new amp break-in for at least a few hundred hours before comparing power cords, if that's what you will want to do. Your Rowland DAC wouldn't mind good cord either, by the way. If you ask for a advice here you will get recommendations for one hundred brands.
Also, if you buy cds, in my experience Japanese cds always sound better, always. JVC XRCDs are quite consistent. Some American cds by audiophile companies like Chesky, Acoustic Sounds, Water Lilli and others can be excellent too. You might also want to use cd treatment, Walker Audio is popular but there are others. I don't listen to digital much so I use inexpensive Optrix treatment. All my treated CDs including Japanese sound better than untreated. At the very least rinse them with lukewarm water and wipe off with soft cloth not paper towel which is abrasive.

Tube preamp with SS amplifier is a very popular choice for many audiophiles so I don’t agree with Inna’s "purist  audiophile " definition.
Rinpoche congratulations on your decision, I suspected that the convenience aspect of the JR (transistors ) would be an important feature. You certainly are impressed with the sound quality and it’s a fine match given your speaker’s load characteristics. I wish you many years of listening enjoymentwith this well chosen pairing.
Charles,
Purists would not mix Chanel with Dior, even though both are French. Chanel is best with Chanel and Dior with Dior. I've seen excellent combinations but they were not the best.
But tube preamp as a buffer when using digital source is not a bad idea if carefully selected.
I guess, in my heart I am a purist after all.