This is the newest copy of the most expensive version of the NFB-10.withi upgraded TCXO; It is the original, much heavier, larger and hand made with better parts and power supply version of the current nfb-10 Second Edition. About a month after AGD announced they were discontinuing all saber DACs including this one, I decided this was the one I wanted and set off to find one in remaining stock. It works perfectly and unlike the other hand-made AGB products I have, it is not covered in markings/imperfections. Also unlike many other AGD DACs that I have had, it plays all signals at all rates and depths without issues. If I remember correctly, I don't think you can quite get to 24/192 via optical (but it will play). It has fixed and variables outs, is fully balanced from input to outputs has SE and XLR headphone jacks and outputs upto 4 watts. 2 ohm output impedance, 21 pounds, 80 watt power transformer, etc ,etc, etc I rather like the amp. The only reason I'm selling is that though it has several digital inputs it has no analog inputs. (and I'm selling now because I'm getting a new amp soon) Note, though this is the much cooler version with an actual volume knob (I will never be a fan of the buttons used now), this is a fully digital and balanced, relay control volume knob. When you turn it you can hear a very cool sounding series of relays cycling with the volume change (you can not hear this through the headphones). Very very slick. The single nicest ''pot'' I've used in any of my gear. This originally cost me $996, comes in the original packaging and all the original cables which were never used, still in bags which were never opened. I will pay shipping but if you want it double boxed, insured or anything else, then that's extra. Asking $725 +pp and I'm in no hurry to move it. But I'll probably never use it again as I haven't used it in a couple months now.