Completely overhauling 1970s Japanese live sound mixing consoles and expanding their capabilities, the Yamaha RTR mods were designed to be the perfect addition to any studio as a sidecar, summing mixer or main mixing console in a modern recording studio. 

Modifications and servicing have varied from iteration to iteration and with custom requests, though generally have involved most of the following:

- Direct Outs (1/4" Unbal.)
- Channel On / Off Switches
- Low EQ Mod - 60, 110, 220 Hz
- High EQ Mod - 10k, 12k, 16k
- Channel and Program OpAmp Upgrades
- Complete Recap and Rebulb