To say I'm bown away would be an understatement, Its taken the standard Nord One NCore NC500 (pretty much same sound as the NCore NC400) to another level. The standard version is superb, highly powerful and acurate and equualed the Abrahamsen beacuse it was different more powerful, cleaner. If you asked me to sit in an average room which you would listen to for hour on end I would pick the Abrahamsen, full stop. Not now, after trying the new input buffer board. We tried both the beautifull Burson V5 it was better, but the full class A Sparkos Labs OP Amp wow it adds a richness, timbre, a warm well just bloddy enjoyable sound. The Hypex then adss the clout its just mind blowing. I really like it in case you were wondering. Here isd the prototype board in action complete with discrete Hypex Voltage regulators glowing away.