This is a review and measurements of the McIntosh MPM4000 Power/dB vintage stereo meter. It is on kind loan from a member and costs used from US $500 to $999.
It had come out in 1997, aimed at automotive market so requires 12 volt power. As you can see in this sample though, it can be readily used in home systems with a case and external power supply.
Unlike every other VU meter we have tested so far which are just for show, the MPM4000 is supposed to be calibrated for a 4 ohm speaker. The purpose of the review then is to see if there is an impact on the fidelity and accuracy of its markings.
FYI the sample I have has very dim lighting. I suspect the originals were brighter.
McIntosh MPM4000 Power Meter Measurements
For testing, I configured the Purifi reference amplifier for 1 watt output. Here it is by itself:
As we expect, distortion is vanishingly small. Let's now connect the MPM4000 in...