Hi there,
I've just received a GS-1 from the latest shipment. I too am using the GS-1 with my JH13s and paired with my benchmark dac1(supposed bright dac) i'm finding sound to be overly bassy and lacking mid and high end definition. This is compared to what i'm use to out of my iphone 3g. The bass almost too strong and a tad bloated and it intrudes into the mids, making them slightly veiled...
If you have an iphone could you chime on if it sounds tonally different when compared to your home setup ?
I've waited 6 months for it to finally arrive and now i'm sorely disappointed :S
While the sound of my iphone doesn't have a large soundstage or micro detail as my home setup... it definitely has a tonally more balanced sound and as of now i prefer the sound from my iphone 3g.