I have an Opus 21 that I bought from Great Northern Sound / Steve Huntley in Minnesota. The Opus 21 was for use in a second system, my first system featuring a fully tricked out Wadia 861 SE with the GNSC Statement modification.
When I first got the Opus 21, I listened to it without modification in a system with a Hovland HP100, Luxman MB3045's and Harbeth SHL5s. The Opus 21 sounded great in that system. The Opus is not "digital" sounding for a unit at its price. It is full and relaxing and I enjoyed it. When listening to my second system, I did not pine for the big rig. It was very enjoyable and the errors were those of omission relative to my 861.
After about a year, I asked Steve to upgrade the Opus 21 to the Reference level. The mod seemed to improve the low end weight and dynamics most prominently. I think that there are other things, too, like noise (decreases) and imaging (improves as soundstage deepens and musicians become more focused). The mod makes the Opus 21 omit less than the stock version.
Overall, I really liked the stock version and had no problems with it. I like even more the GNSC Reference mod version but do not think that it is necessary to begin to enjoy the player. It's just a nice improvement to make if the funds allow.
One more thing: If you get the chance, you can use the DNM DIN to RCA cable from the back of the Opus 21 and it makes a subtle but nice improvement. This does not allow you to use the Opus 21 volume control but is worth considering for the nominal cost ($125 or so) if you have a preamp you intend to use anyway.
The Opus 21 is a great unit and can be made better if you want (but it is not necessary to begin enjoying it). I now use mine with a Wadia 170i iPod dock and enjoy it for that application, too.
When I first got the Opus 21, I listened to it without modification in a system with a Hovland HP100, Luxman MB3045's and Harbeth SHL5s. The Opus 21 sounded great in that system. The Opus is not "digital" sounding for a unit at its price. It is full and relaxing and I enjoyed it. When listening to my second system, I did not pine for the big rig. It was very enjoyable and the errors were those of omission relative to my 861.
After about a year, I asked Steve to upgrade the Opus 21 to the Reference level. The mod seemed to improve the low end weight and dynamics most prominently. I think that there are other things, too, like noise (decreases) and imaging (improves as soundstage deepens and musicians become more focused). The mod makes the Opus 21 omit less than the stock version.
Overall, I really liked the stock version and had no problems with it. I like even more the GNSC Reference mod version but do not think that it is necessary to begin to enjoy the player. It's just a nice improvement to make if the funds allow.
One more thing: If you get the chance, you can use the DNM DIN to RCA cable from the back of the Opus 21 and it makes a subtle but nice improvement. This does not allow you to use the Opus 21 volume control but is worth considering for the nominal cost ($125 or so) if you have a preamp you intend to use anyway.
The Opus 21 is a great unit and can be made better if you want (but it is not necessary to begin enjoying it). I now use mine with a Wadia 170i iPod dock and enjoy it for that application, too.