Welcome! The prices for HD 700 and HDVA 600 are excelent at Amazon.com right now.

The HDVA 600 is OK with low impedance headphones. With them the sound difference is less noticeable. Sounds like have no amp, a passthrough device.

I recently purchased Moon Audio Black Dragon v2.   Moon Audio Black Dragon or Cardas Clear vs Sennheiser CH800S is a trade off between low and high frequencies.   Moon Audio Black Dragon and Cardas Clear boosts low frequencies, but high frequencies are not as clear as in stock cable.  ...