As long as theres no issue with them not conducting properly theres zero difference in sound.
Headphones
A community for discussion around all topics related to headphones and personal audio.
A short version of a 6.35mm to 3.5mm adapter literally ripped off the tip of the 3.5mm plug on one of my headphone cables when I tried to remove it from the adapter. This was due to a manufacturing defect and due to the very limited space inside the short version of the adapter. I use this longer version of a 6.35mm to 3.5mm adapter since they are much better constructed:
https://www.amazon.com/gp/product/B077F3Q5WC
I perceive zero difference in audio quality when using the above adapters, and I have zero issues when plugging a 3.5mm cable into these adapters or plugging these adapters into a 6.35mm socket.
3.5/6.35 = ~0.551 so you will only get 55.1% of the sound, which means it will sound only 55% as good as the 6.35mm.