IIRC he has a few thousand of these 6AU6 tubes that he got in bulk. So he has designed most of his tube applications around these tubes. About why to use tubes

IIRC he has a few thousand of these 6AU6 tubes that he got in bulk. So he has designed most of his tube applications around these tubes. About why to use tubes? I don't know, entertainment purpuoses I guess. His ventures into computing using tubes entertain some at least[0]. [0](n=1)