The higher gain is the MC board, and the lower gain is the MM board. The 38db or 58db relates to phono section gain only, and the linestage also has a gain figure(typically between 10db-20db). The phono gain and the linestage gain are added together to get total gain in the front end.
If you add in the step-up transformer, it will also be added into the front end gain. I've found that the total front end gain with the DL103R is good at about 80db total front end gain. My system has a Cotter step-up(20db), 46db phono gain, and 20db linestage gain, for a total front end gain of 86db. This worked out very well for me when I was using the DL103R in my system.
Remember, that when you use a step up transformer, you load the cartridge AT THE TRANSFORMER at half the normal amount(40-50 ohms) instead of the 100 ohms. You then use the normal 47k loading at the phono section input. The Cotter is difficult to adjust loading on(soldering jumpers), so I hope that the one you have is the "Type S" version of the Cotter Mk2 tranny.
If you add in the step-up transformer, it will also be added into the front end gain. I've found that the total front end gain with the DL103R is good at about 80db total front end gain. My system has a Cotter step-up(20db), 46db phono gain, and 20db linestage gain, for a total front end gain of 86db. This worked out very well for me when I was using the DL103R in my system.
Remember, that when you use a step up transformer, you load the cartridge AT THE TRANSFORMER at half the normal amount(40-50 ohms) instead of the 100 ohms. You then use the normal 47k loading at the phono section input. The Cotter is difficult to adjust loading on(soldering jumpers), so I hope that the one you have is the "Type S" version of the Cotter Mk2 tranny.

