Marantz

Your out of luck trying to replace the main power fuse on the Marantz SA11-S1 as it is hardwired into the unit. But you can try a WA Quantum chip ($6.00 ) placed on the fuse or try the Synergistic Research Electronic Circuit Transducers ( ECT ) places next to the fuse. My  Marantz unit has the WA chip and seven of the Synergistic Research ECT's inside. I did replace the five rail fuses with the Synergistic Research Black fuses. 1.6 amp, small, slow blow. Each fuse location did make a sonic difference but I did not try to establish which location made the greatest difference.

This unit really sounds good after these upgrades and they are removable if you sell the unit.

David Pritchard

SA 11s2 owner here. good to see some discussion of how to make the unit sound better. I will be trying the main fuse replacement shortly. One reminder - check your filter setting. Mine was somehow set to three, probably for a long time. I went back to one and found more clarity and a more natural bass response out of my ProAc D15's. 

Which fuses do I replace once I get the lid off

Not Audioquest, but Darwin Ascension ICs and Zu Audio Event (series I) SCs. It's the best sound I've gotten out of it so far.

All the best,
Nonoise