+1 Charles
The OP's opening statement was the desire to replace a high gain DAC with one having less gain.
Well, The OP has a DAC with 4.3V output, far more than needed. Also a high gain preamp and high sensitivity amplifier which on technical basis may not be ideal, however how these play together with the speakers satisfies the OP who only is looking to reduce gain to take better use of volume control. Seems to me that replacing the DAC with one having less than 2V output would reduce the gain by close to 10dB at the source with the least alteration of the sound quality of the system and allow greater degrees movement on volume control.
The OP's opening statement was the desire to replace a high gain DAC with one having less gain.
Well, The OP has a DAC with 4.3V output, far more than needed. Also a high gain preamp and high sensitivity amplifier which on technical basis may not be ideal, however how these play together with the speakers satisfies the OP who only is looking to reduce gain to take better use of volume control. Seems to me that replacing the DAC with one having less than 2V output would reduce the gain by close to 10dB at the source with the least alteration of the sound quality of the system and allow greater degrees movement on volume control.