Gammajo,
I am using a Supratek Cortese tube preamp and a Berning ZH270 tube power amp with my Northstar/Extremo DAC combo. This is the best cd sound I have ever achieved in my system. Beats the Sony scd-1 player I had (and it had the VSEI mods). I am using Gallo Reference 2 speakers (90 db efficiency).
I am using a Supratek Cortese tube preamp and a Berning ZH270 tube power amp with my Northstar/Extremo DAC combo. This is the best cd sound I have ever achieved in my system. Beats the Sony scd-1 player I had (and it had the VSEI mods). I am using Gallo Reference 2 speakers (90 db efficiency).