I realize that the OP has probably resolved their issue by now, but I am posting this to help anybody now who gets one of these units with no documentation. In 2014, I wanted a tube head amp. At the time, Music Reference, Audion, and Dulcet Lector appeared to be the only folks making a dedicated tube MC head amp. The Audion and Dulcet Lector units were over $2k, while the RM-4 was $1250. Also, the RM-4 was pretty much the original commercially available unit, having been introduced in the ’80’s, so I went with it. It took 10 months from order to completion, and was an amusing and somewhat surreal purchase experience. I knew that no one had ordered one in quite awhile because the website showed the price as $750. When I called, I was told it would be $1250. I told Roger it would be nice if he would give me the info to be able to set the loading and gain with discrete resistors rather than having to buy a bunch of plug-in modules. He kindly included a hand-drawn note showing how to do this.
I can’t seem to be able to upload an image of his note to my response. I just sat here trying to see if I can explain it in words, but it’s a bit complicated. If anyone happens on this post who wants the loading and gain info, you can either let me know if it’s possible to upload an image, or just contact me through the website, and I can email you a scan of it. It’s pretty self-explanatory if you have a little basic electronics knowledge.