It would contact McIntosh regarding your question.
Also, I do not like KT120s either. Too much bass, grainy, dull... really not a good tube. I put my Gold Lion KT88s back in my amps and never looked back. From what I have been told the KT150s are no better.
Also, I do not like KT120s either. Too much bass, grainy, dull... really not a good tube. I put my Gold Lion KT88s back in my amps and never looked back. From what I have been told the KT150s are no better.