Are you unhappy with the performance or your Cayin or just looking to get the most out of it you can?
I have a Cayin A-300P which appears to have the same configuration. There is no active preamplifier stage, only a volume pot and input selector with the power amp stage. So it is not a true "integrated" amp.
If you read much about "passive preamps" (what an unfortunate term!) you will learn that many hobbyists prefer them, while others are satisfied only with an "active" preamp. Advantages can be listed for each design. I think it boils down to system compatibility and personal taste. See if you can borrow a couple of different tube-based active preamps from dealers or friends and decide for yourself.
I have a Cayin A-300P which appears to have the same configuration. There is no active preamplifier stage, only a volume pot and input selector with the power amp stage. So it is not a true "integrated" amp.
If you read much about "passive preamps" (what an unfortunate term!) you will learn that many hobbyists prefer them, while others are satisfied only with an "active" preamp. Advantages can be listed for each design. I think it boils down to system compatibility and personal taste. See if you can borrow a couple of different tube-based active preamps from dealers or friends and decide for yourself.