kalail, I suspect Don is too busy to have time for much internet posting. I think it is a one-man operation, other than building the cases. So I'll share what I believe to be the development.
First off he has a long-standing reputation for restoring and upgrading classic tube gear such as HK Citation, McIntosh, Marantz, etc. Somehow he had the opportunity to examine the circuit for the VTA-SP14 and was impressed by the potential. But he felt it could be improved by selective parts upgrades. So he ordered the board and built one to test. Being satisfied with the initial results he then refined that and began offering his own version, with the blessing of VTA. After all, they reference Don's version on their own site.
Since then it has been word-of-mouth promotion. That's how I learned about it and I couldn't be more pleased with my DS2 SP-14.
First off he has a long-standing reputation for restoring and upgrading classic tube gear such as HK Citation, McIntosh, Marantz, etc. Somehow he had the opportunity to examine the circuit for the VTA-SP14 and was impressed by the potential. But he felt it could be improved by selective parts upgrades. So he ordered the board and built one to test. Being satisfied with the initial results he then refined that and began offering his own version, with the blessing of VTA. After all, they reference Don's version on their own site.
Since then it has been word-of-mouth promotion. That's how I learned about it and I couldn't be more pleased with my DS2 SP-14.