having owned both, the midrange always felt "off" to me with the WA7. There was no body to the sound, imo. The HA-1 has virtually perfect, transparent mids. I did find the tube highs on the Woo to be superior, although this could be due to the dac and not the amp. Overall, i really prefer the Oppo. Btw, the HA-1 is a killer preamp. I use it for for my pro-ject turntable, using a lounge audio mk iii phono preamp going into the Oppo. This thing is a secret weapon.