Albert, Thanks for the information. Genelex KT66s! When I asked Kevin about that, he wasn't sure if circuit required a modification for these tubes. Two power supplies!!! Wow! Can you give me a rough idea on improvement as compared 1. Changing tube brands 2. The change to KT-66s 3. Going finally to 2 PS. I am very interested in your thoughts. Sen d me a direct members e-mail if you can. What about better caps in the phono section? What do you know about that? Thanks again. I love this pre-amp, but I am still the hobbyist. Cheers, Gerry Will Jim do this for other customers?