6sn7 substitute for Cary Sli-80

Hi, Does anyone know if you can substitute a ecc33 for the 6sn7's in the Cary Sli-80? I have put an email in to Cary, but as it is Friday night, I probably won't hear back for a while. Any help would be appreciated.

Wait to hear directly from Cary. The ECC83 was commonly used in computer switching mechanisms. It's ability to repeatedly switch off and on in a circuit may be a cause of damage to other component parts unless Cary designed the circuit of the amplifier to specifically accomodate this feature. Unlikely the ECC83 would have any particular sonic advantages either.
Sorry for the typo, ECC33. Not 83.
Cary says yes,

Thank you.