I've a friend who has been using a soul sister preamp for quite some time and is finally looking to try something different. He knows I'm a bottlehead fan and asked me to look into it. I couldn't find much about this - other than it was mostly offered as a plan and not commercialized, maybe due to transformer cost. I've shared a few photos from the pre and was wondering if anyone here would be interested in sharing some thoughts or advice I can pass along as they are planning to list it on the used market.