I was skeptical that this product would significantly improve the sound of my NAD PP2 phono pre-amp. A complete recap and a better power supply had showed definite but not dramatic improvement. Installation of the Burson V6 Vivid demonstrated instantaneous incredible improvement… more than any other single DIY upgrade I have done. The sound was improved in every aspect… sound stage, transparency, broad frequency response! I have now ordered V6 Classics for an Oppo 105 and will consider upgrades to my already modified Crown SL-2 and PL-4s.