Cardas HPI-A is an female 6.3mm jack to male 3.5mm minijack adaptor, with the Cardas connector and conductor quality.

Use Your 'Home Listening' Headphones with Your Portable Player.
If you've been wanting to hear how good your iPod or other portable audio device can sound with a pair of audiophile-grade headphones, Cardas Audio has got you covered. The Cardas Phono to Mini Cable Adapter lets you plug in your premium 'home listening' 'phones to your 'on the go' player, such as an iPod or iPhone. It's great for computer audio, too.

The quality is exactly what you would expect from Cardas. Premium-grade Cardas wire and custom connectors make this the best phono to mini adapter you can buy!

This adapter consists of a female 1/4" connector on one end and a male 1/8" mini-plug on the other end.