...I'm thinking about mounting a position switch for different load resistances(not at all complicated)that I can design as an external unit that connects in-parallel to the rear pannel through the locking pins so that won't degrade a look of the unit. Can it degrade a sonic performance and how and in what cases? Also Is there any possibility to acquire SE upgrades kit?
i do not know about the diy switch. but michael percy audio sells a se type upgrade kit for the ph3. i hear it is essentially the same thing as the arc version. i did not do the upgrade. i just bought a different phono stage.