For size comparison purposes, here from left to right are the SuperMicro IV, The Tomahawk, The Reference, The SR-71, and The Larocco PR II.
I am going to post some early impressions of the Reference, and since there is so much enthusiasm about this unit, and so few of them around, I know people are hungry for information. Please take my impressions as the experience of one person and not any definitive pronouncements.
The Reference has been burning in constantly since yesterday afternoon when mrarroyo left it with me. I have listened to it on and off getting some impressions and giving it time. I will post my impressions of the sound at this point in comparison to the post 4/11 Supermicro. I used a 4G redwine Imod, ALO cotton mini to mini, and the following headphones: K701, RP-21, UE Triple-Fi, and Shure E500. My impressions were consistent across all these phones.
First, the Reference is definitely powerful, with strong bass and good detail and a wide soundstage. You can feel a certain intensity to the sound. I imagine bass lovers would appreciate this aspect of the Reference. However, at this point, the depth of the soundstage is not as good as the width. The Micro has much better depth and texture to the soundstage, and at least to my ears, equal width. The micro does not have the bass impact of the Reference, but has excellent quality bass without the visceral impact or power that you can feel in the Reference. Considering the different power requirements, this would seem appropriate.
On the other hand, the midrange and treble of the micro sounds more liquid and extended than the Reference. The sound of the micro has wonderful depth, air, and spaciousness. The Reference doesn’t seem to have quite the sense of air and openness, or a sense of musical aliveness that the micro gives you. The micro is so damn suave and musical, you have the sense of depth and envelopment in the sound without being bombarded with it. The Reference has a heavier, more intense presentation that is big and powerful, but not as deep as the micro.
Also, I do not think the treble extension of the Reference is quite as good as the micro, the overall sound presentation is just a bit darker in color at this point. You can hear this clearly when listening to male vocalists, with the Reference giving a slight emphasis on the lower range of male voices, while if you listen to the same recording with the micro, you hear the lower elements, but also more subtle tones in higher registers of the voice that are not as evident with the Reference.
I do not know how the Reference will sound with more burn-in time, it is likely to continue to change. If it responds to burn-in like the Tomahawk did and around the 400 to 500 hour mark blooms and opens more in any way similar to the Tomahawk, the soundstage and bass impact will be humongous, because it is very wide and strong now. We will have to wait and see. It will continue burning in 24/7, until mrarroyo gets back in town and picks it up. Also, the new board will cause changes, and I hope will give it some improved treble extension.
I know there was some tendency to think of the Reference as a micro on steroids in some earlier posts, but the sound signature is more like the mini, or the Macro LE than the micro, at least to my ears. If forced to choose only one at this point, I would choose the micro for it’s overall musicality, depth, airiness, and texture.