Don Sach's pre amp

yes I have looked at Tube-o-Phile on A/C , what I am trying to find out is how does it compare to primaluna and  Rogue audio pre- amps , since they are priced at a similar price level. I have listened to a Prima Luna amp at the Oakland Audio show 2017, which sounded very good .

Here's a link with some customer reviews toward the bottom.  The last one is from a guy who compared directly to ARC and Prima Luna preamps...

http://www.tubes4hifi.com/SP14.htm

I have one. Beautiful preamp. I went for all of Don's upgrades (except for XLR).

Tube rolling makes a big difference.

I originally tried it with 4 x Psvane CV-181z Selects, but found the bass frequencies too 'muddy'. The sweet spot was 2 x CV181z's and 2 x chrome top Sylvania 6SN7's.

Is it possible to have them in full balanced configuration (not just XLR in)? Has anyone compared them to much more expensive preamp?

@radiohead99

Give Don Sachs a call. He's always willing to talk about his builds.