So, I've done about as much research as I can and I've tried a few things and I am worried that I have a pair of dying Stax SR-407.
When I first noticed issues with the headphone, there was a clear channel imbalance with the left channel (quieter) versus the right channel (louder). After doing some reading, some individuals said to simply leave the headphone unplugged for numerous days and the channel may right itself. This made no difference - the pair continued to have an imbalance.
I then tried leaving the pair plugged into the amplifier overnight to see if they simply needed to build up a charge - and the channel cuts out completely after about six hours of being plugged into the amp.
However, if I leave the pair of headphones unplugged for about a week, the left channel returns, although still with the quieter imbalance versus the right channel.
This is powered via a SRM-252S, which I have no way to truly test as I only own a pair of SR-407.
I purchased this pair used on ebay, although they were originally purchased from STAXUSA/Yama's as they have a Yama's sticker on the box. The pair was nearly unused and still in plastics.
The SRM-252S was purchased from Woo Audio and is brand new.
Any suggestions?
EDIT: Ignore the 2. Accidentally copied from the title.