Low sound buzzing after installing Sound Blaster Audigy RX 7.1 Sound Card > Astro Mixamp > Sennheiser 598

[BU MA]

There is a faint buzzing sound while on lower volume or no sound at all.

 

Sound cards output is optical out cable to an Astros mix amp, from the mix amp I plug my Sennhister 598's.

 

Could the Astro mix amp be bottle-necking my audio performance? On the Sound blaster software, it is set to 48 KHz, If I set it to 96 KHz it will start making a cracking sound.

 

[BU MA]

4 hours ago, valkko said:

Optical is limited  by the standard to 48 khz, anything above that Frequency Will cause distortion

Didn't know that. Ive now directly plugged my headphones into my sound card and not used thr Astro mix amp and the sound quality is amazing. 

 

Would it make sense to use 7.1 with 48Khz? versus headphones options in the software. I find the 7.1 sound to be amazing but im not sure if thats really optimal for headphones. 

[rice guru]

coud the mixamp be affecting it? have you tried plugging it firectly to the soundboard or motherboard audio outs?