Great amplifier! I wish I had not sold mine.
It is very difficult to bi-amp with different amplifiers and achieve a coherent sound. I have never managed to do it properly, even with matched gain amps. Each amp has its own speed and sound signature.
Option two is a paralell configuration for current-hungry speakers.
From the Mac site:
MONOBLOCK
The two 75-watt channels may be combined into a single channel of 150 watts
into 2, 4 or 8-Ohm loads."
Note that 16 ohms is no longer an option and 2 ohms is available for power-hungry speakers.
Option 2 will probably sound better in the bass than option 1, given that your speakers have low to medium efficiency...however, option 1 (vertically bi-amping) separates the bass signal (heavy current demands on the tubes) from the midrange and treble signal (low voltage, low current, requires extremely low distortion). It will probably sound best regarding midrange cleanliness and soundstaging.
So, I believe we have come full circle: you should try and see what you like best.
Good luck
It is very difficult to bi-amp with different amplifiers and achieve a coherent sound. I have never managed to do it properly, even with matched gain amps. Each amp has its own speed and sound signature.
Option two is a paralell configuration for current-hungry speakers.
From the Mac site:
MONOBLOCK
The two 75-watt channels may be combined into a single channel of 150 watts
into 2, 4 or 8-Ohm loads."
Note that 16 ohms is no longer an option and 2 ohms is available for power-hungry speakers.
Option 2 will probably sound better in the bass than option 1, given that your speakers have low to medium efficiency...however, option 1 (vertically bi-amping) separates the bass signal (heavy current demands on the tubes) from the midrange and treble signal (low voltage, low current, requires extremely low distortion). It will probably sound best regarding midrange cleanliness and soundstaging.
So, I believe we have come full circle: you should try and see what you like best.
Good luck