I have a Musician Monoceros preamp for which I don't have the remote, unfortunately. By an incredible luck I have managed to get one IR code for POWER_DOWN. Basically, I saw that when my Samsung TV gets a new HDMI input, it sends some IR codes and one of them turns off the preamp. I intercepted that code using a RPI and IR transceiver. Encoding is MCE and by playing a bit with irScrutinizer (D, S, F, T values variations), I managed to find some more codes. However, I did not manage to find VOL_UP code and I am a bit stuck now. Of course, the most important functions are VOL_UP and VOL_DN. I have to say that my knowledge regarding IR transmission is limited.
Here is what I have at the moment: I am hoping that more knowledgeable people can help to find the VOL_UP code.
begin remote
name proper flags RAW_CODES eps 25 aeps 100 ptrail 0 repeat 0 0 gap 20921