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
By the way, I should clarify that it is the Jeff Rowland 625 S amp that I am referring to. 
all the best! Rinpoche
@rinpoche You are in for a great treat--the Aeris+Corus+PSU combo is very good at the beginning and superb after the burn in is completed. I run my combo with JR M925s and couldn't be happier with the results.
Enjoy!
Al
Thank you Al. That is so sweet. I am very happy. And I feel very fortunate to even be having this conversation. I look forward to finding that sweet listening experience. Wow M925S !!! You must have quite a room. 
I have VAC Phi 200s and it literally takes me five minutes and no techie equipment to bias them. Just adjisting an easily accessible screw for each tube and watching for an led to light up. Really simple.  Output tubes cost about $40 each and should last at least 2000 hours. You can start listening immediately after turning it on, and takes 10-15 minutes to really warm up. I have utmost confidence in the reliability of these amps, more so than ARC or others.  And a Kevin Hayes is a true, patient gentleman.  My 2 cents!