There is a difference and it is worth the price difference from the Bifrost 2/64 and the Yggy+ OG. My opinion is yes there is difference and I did not return the Yggy+ OG to Schiit within the 15 day return period. I had a chance a listen to Mjolnir 3 (MJ3) and the Yggy+ OG at the SOCAL Can Jam at the Schiit booth. I brought along my Denon AH-D9200, Schiit had the MJ3 and the Yggy+ OG paired together and I was impressed with what I was hearing. So much so when I arrived home, I immediately ordered the MJ3. Several months later in December the MJ3 arrived and while there was several months since I listened to combo at Can Jam, I felt something was missing from what I remembered. So, in January I took the leap and purchased the Yggy+ OG. Once I brought it home from the Schiitr (l live in driving range from the Schittr). I placed the Yggy+ OG into my system and what I remembered from the Can Jam was once present in my ears when listening to my favorite music. I am not great at explaining how something sounds but with my current setup it sounds more alive with greater detail. I will not get rid of my Folkvangr but the MJ3 has more detail sound. While owing the Folkvangr I am running Mullard E88CC tubes (they are my favorite).