I am a Frankenstein owner. I had the Coincident Statement Line Stage and currently use Horneshoppe The Truth T3. Both are superb with the Frankensteins. The Truth T3 is a no gain unit and works best with source components with output voltage of 1.8 volts or greater, which is the vast majority of components. There is a T4 version that provides gain if needed. The Truth has remote control and balance control, the CSLS does not.
Arthur Salvatore did comprehensive reviews of the CSLS and The Truth which may be of assistance: