As comments above, there are various kinds of what you are looking for. Some have "digital volume" about which some believe is not too great (volume decreases -> bits are dropped -> less resolution, etc.). Some have just a potentiometer to attenuate the analog output level (like having a passive pre after the CDP). Some have (relatively) serious pre-amp section on board (some even accepts "analog" inputs so that it REALLY works as a pre-amp).
Cost varies, and sound may vary. Of course, your mileage may vary, as well. Ken
Cost varies, and sound may vary. Of course, your mileage may vary, as well. Ken