Need Help: Can't recall which hi-end R2R dac had an optional preamp board?

Title says it all. Ive searched here, google and YouTube. Seems it was a coparo on YT

tweak105-03-2022 1:02pm

lordmelton Details Discussions Posts This discussion Message User 877 posts 05-03-2022 at 03:26pm Copy Comment URL Report Comment Edit Delete I believe it's the Holo Audio Spring with optional real pre-amp board.
whipsaw Details Discussions Posts This discussion Message User 758 posts 05-03-2022 at 04:34pm Copy Comment URL Report Comment Edit Delete Holo Audio Spring for sure.
gregm Details Discussions Posts This discussion Message User 3,405 posts 05-04-2022 at 08:45am Copy Comment URL Report Comment Edit Delete Had an optional pre: MSB Select II, I had one. Not disputing the others, but can confirm this one.
tweak1 OP Details Discussions Posts This discussion Message User 3,668 posts 05-04-2022 at 01:51pm Copy Comment URL Report Comment Edit Delete Thanks guys Yes, it is the Holo Spring