What is the input impedance of your Viva amps? Usually tube amps are 100k ohms or so?
I have owned both the Samsons and Mac 402 amps so I know how they differ. The Mac amps sound rather dull and lifeless compared to the Samson amps. I liked the 402, but my point is still accurate. The Samson amps offer improved resolution, detail, imaging and jump factor. The Samson amps also have tighter, more articulate bass. The 402 has a nice big and warm sound. The 402 is like taking a warm bath.
The Samson amps do have the ability to sound intimate like a SET amp, however they don't quite match the body, texture, tone and 3D dimension of a great SET amp. The Samson amps will play music with a greater sense of scale, impact and ease compared to your Viva amps however.
I have owned both the Samsons and Mac 402 amps so I know how they differ. The Mac amps sound rather dull and lifeless compared to the Samson amps. I liked the 402, but my point is still accurate. The Samson amps offer improved resolution, detail, imaging and jump factor. The Samson amps also have tighter, more articulate bass. The 402 has a nice big and warm sound. The 402 is like taking a warm bath.
The Samson amps do have the ability to sound intimate like a SET amp, however they don't quite match the body, texture, tone and 3D dimension of a great SET amp. The Samson amps will play music with a greater sense of scale, impact and ease compared to your Viva amps however.