I did switch the power set-up to bypass the pre-amp and actually got a hum! Switched it back and was fine.
I'd be very surprised if there would be a noticable increase in sound quality by powering the amp differently. I am more concerned about too much voltage running through the Pre.
I did in fact dig out the SP-12 Pre-amp manual I've had since 1985 and it does specifically refer to plugging the amp into the switched outlet on the back of the Pre-amp.
The SP-12 has two power switches. The instructions state to use the 1st switch on the Pre to power just the Pre, wait a minute for it to warm and then press the second power button which then activates the switched outlet on the back and allows the amp to power-up.
Of course after all these years I hardly wait a minute between depressing the two switches and click the second switch right after the first.
As I said, I haven't run into any issues and very pleased with the sound so I guess it works fine as is. Maybe I'll be more diligent in letting the Pre warm a bit before powering the amp.
I'd be very surprised if there would be a noticable increase in sound quality by powering the amp differently. I am more concerned about too much voltage running through the Pre.
I did in fact dig out the SP-12 Pre-amp manual I've had since 1985 and it does specifically refer to plugging the amp into the switched outlet on the back of the Pre-amp.
The SP-12 has two power switches. The instructions state to use the 1st switch on the Pre to power just the Pre, wait a minute for it to warm and then press the second power button which then activates the switched outlet on the back and allows the amp to power-up.
Of course after all these years I hardly wait a minute between depressing the two switches and click the second switch right after the first.
As I said, I haven't run into any issues and very pleased with the sound so I guess it works fine as is. Maybe I'll be more diligent in letting the Pre warm a bit before powering the amp.