not sure what a "pre Koda" might be?
never heard the term. maybe you mean a Robert Koda preamp? if so the way you said it is confusing. and then 'Dartzeel'.......do you mean a darTZeel preamp? compared to a Robert Koda preamp?
it would be unusual to have compared those two products as the are viewed both as solid state alternatives that resemble how tubes sound. so typically you might try one or the other but not both.
re-state your question in clearer terms and maybe someone will respond. i'm a darTZeel owner who has never compared my gear to Robert Koda or heard the compare. so i have nothing to offer you.
i hope that helps.