I recently got my Insight Double 440H amplifier upgraded with the "+" upgrade, so it is now an Insight+ Double 440H! I'm enjoying the increased clarity I'm hearing in the music, more defined bass, and smoother treble. I normally listen at low-to-moderate volumes. I now notice that if I turn the volume up a little, I no longer get comments from other family members, to please turn the music down. Decreased listening fatigue is a good thing.
Even though the results of this upgrade have been elsewhere described as subtle, it is well worth the cost. Thanks Frank, for the great work in developing the "+" Upgrade. I continue to be a long-term happy customer.
