Glad you are finding that you like them!
I don't think it is the HE400SE. And I don't necessarily think it is the stereo itself, though it could be. The most likely suspect and the weakest link in your chain is the phone and connection to the stereo. You are basically double amping the music, and you are sending it via an unclean connector. Try listening to a different source from the stereo without the phone in the mix. Put a record on and listen to it. If it isn't the stereo (or the input you are using into the stereo) then you shouldn't have distortion. On the other hand, given the age of that amp/stereo it COULD be the KA.
Remember, the best sound you will get will be decided by the weakest part of your chain. To avoid spending a ton of money down the road, I have curtailed buying a bunch of separate equipment, and just bought a great mid-tier DAP. Now I can just go straight from that to the headphones, and don't have to worry about portability, power, clean connections, etc...
I don't think it is the HE400SE. And I don't necessarily think it is the stereo itself, though it could be. The most likely suspect and the weakest link in your chain is the phone and connection to the stereo. You are basically double amping the music, and you are sending it via an unclean connector. Try listening to a different source from the stereo without the phone in the mix. Put a record on and listen to it. If it isn't the stereo (or the input you are using into the stereo) then you shouldn't have distortion. On the other hand, given the age of that amp/stereo it COULD be the KA.
Remember, the best sound you will get will be decided by the weakest part of your chain. To avoid spending a ton of money down the road, I have curtailed buying a bunch of separate equipment, and just bought a great mid-tier DAP. Now I can just go straight from that to the headphones, and don't have to worry about portability, power, clean connections, etc...