Alpha Dog: Prime Time The AD is already considered a reference quality closed headphone that manages to deliver champagne on a beer budget. It's known for good mids, nice punchy bass, extended if not slightly peaky treble (although the dog treats work admirably to alleviate this issue with the treble). Now enter the AD Prime. The production model that I was sent looks like any other AD, beautiful 3D printed claret cups and all. I imagine that Dan will differentiate between the AD and the Prime in the final production version. The difference between the two however does become instantly obvious as soon as you cue up the music with the Prime. The Prime is quite simply an evolution in sound quality of the original. I know that Dan has struggled with the inconsistencies of the Fostex driver in his quest to deliver the best product possible. I can't share exactly how Mr. Speakers has “re-engineered” the driver because honestly, I just don't know. Regardless, the proof is in the pudding and the effort of Dan and his team is immediately gratifying when cuing up music with the Prime. I played through several of my regular test tracks to evaluate the Prime, going back and forth between it and the original. The first track I used was Alison Krauss: Stay. The vocals in this track are rich and expertly recorded. From the first breath Ms. Krauss takes, the Prime renders a more natural and grain free vocal. There is delicacy and nuance in the mids that the original AD simply could not reproduce in the same way. The guitar plucks and hi-hat cymbals in this track aren't smeared into the background but heard clearly and accurately, adding to the feeling of listening to live music. I've always felt that the AD was one of the best “open sounding” closed headphones on the market today. The Prime is able to improve on that formula offering a bit more width and depth. This improvement really helps to “de-congest” the staging and create more room around the singer and instruments. Listening to music with the Prime was simply just more enjoyable. This new iteration is not unlike the evolution of the Mad Dog to the Alpha Dog in some ways. Except in this instance the transformation happens more in development and advancement of the sound rather than simply the outer appearance. The original AD was always one of the best buys in the game in term of price to performance, often being mentioned in the same breath with flagship products but sold at a mid-fi price. The Prime delivers Mr. Speakers onto the big stage with other true audiophile flagships products. Another wonderful product offered by Dan and the Mr. Speakers team.