McIntosh MPM4000 Power Meter Review

[peng]

Not quite. A modern version should have an adjustment that allows you to dial in the nominal load impedance.

Agreed, but then if you are that serious about real world accuracy, then we need something more outside the box, that is, we need one that can display instantaneous, average, and RMS voltage and current (programmable, selectable by push buttons, apps etc.) rather than a single popular yet anecdotal metric, i.e. average power, one (there are more) reason being such meters will most likely be used with loudspeakers, not dummy resistor loads. Those Mc meters are just nice and fun to look at.

 

[Dzhaughn]

What no tubes?

 

[JDS]

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.
View attachment 424110
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:

View attachment 424111
As we expect, distortion is vanishingly small. Let's now connect the MPM4000 in parallel to left (1) channel:

View attachment 424112

There is no impact whatsoever which is a relief.

Now let's test for accuracy. I measured the above on the meter and it was accurate, subject to optical error. I then jumped to 10 watts and it too was accurate:
View attachment 424113

I then went up to 100 watts and it too was accurate. So mission is accomplished!

Conclusions
We have had many discussions of vintage meters on power amps being accurate (or not) in the context of new versions which clearly are not. I did not know what to expect but was pleasantly surprised to see that not only is it transparent but that it is also accurately showing power output of the amplifier.

The only negative is the astronomical pricing of it. I guess half of that is for the "status" sake.

I am going to recommend the McIntosh MPM4000 power meter if you don't have to tap into kid's college education fund to buy it!
------------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

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.
View attachment 424110
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:

View attachment 424111
As we expect, distortion is vanishingly small. Let's now connect the MPM4000 in parallel to left (1) channel:

View attachment 424112

There is no impact whatsoever which is a relief.

Now let's test for accuracy. I measured the above on the meter and it was accurate, subject to optical error. I then jumped to 10 watts and it too was accurate:
View attachment 424113

I then went up to 100 watts and it too was accurate. So mission is accomplished!

Conclusions
We have had many discussions of vintage meters on power amps being accurate (or not) in the context of new versions which clearly are not. I did not know what to expect but was pleasantly surprised to see that not only is it transparent but that it is also accurately showing power output of the amplifier.

The only negative is the astronomical pricing of it. I guess half of that is for the "status" sake.

I am going to recommend the McIntosh MPM4000 power meter if you don't have to tap into kid's college education fund to buy it!
------------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

Bright blue VU meters for an automotive dashboard? I guess distracted driving isn't just a recent thing.

 

[Multicore]

Those Mc meters are just nice and fun to look at.

Indeed, a lot of people do like the old needle pointer meters and it's up to me to wonder why. I suspect it might be because they are what sophisticated gear had before this idiotic nonsense appeared on everything

Today this animation in user interfaces meaning "audio is playing" and is often (usually?) disconnected from the actual signal, i.e. it's a vestigial reference to a gimmick nobody cares about any more. Kinda weird, more so than pseudo power meters.

Personally, I don't much care for needle pointer meters. Gimme a decoratively designed vector-scope. We should probably have a thread to collect everyone's favorite visualizers. Or do we already have that?

we need one that can display instantaneous, average, and RMS voltage and current (programmable, selectable by push buttons, apps etc.) rather than a single popular yet anecdotal metric, i.e. average power, one (there are more) reason being such meters will most likely be used with loudspeakers, not dummy resistor loads.

Audio Precision should think about making an analyzer that fits a single DIN car radio slot.

 

[GXAlan]

Gimme a decoratively designed vector-scope.

Audio Classics - MI3

Audio Classic's buys and sells the finest in home audio/video equipment

www.audioclassics.com

 

[Multicore]

Audio Classics - MI3

Audio Classic's buys and sells the finest in home audio/video equipment

www.audioclassics.com

Wow!

The screen is pokey but I gotta hand it to Mc. It's a vectorscope! Awesome. I've been messing around with Signalizer which is cheaper than anything Mc and has more even knobs.

 

[GXAlan]

Wow!

The screen is pokey but I gotta hand it to Mc. It's a vectorscope! Awesome. I've been messing around with Signalizer which is cheaper than anything Mc and has more even knobs.

It was from 1964 which is even cooler. It used the 3” CRT that was used in real oscilloscopes at the time.

http://www.tubebooks.org/file_downloads/McIntosh/MI3.pdf

A company like @MAMORITAI Audio / @Fosi Audio could release a lot of vintage, mid century modern style luxury audio jewelry.

What made McIntosh great was its reliability and performance (relative to era). With that brand, they can sell based upon looks alone.

We have great audio performance today, but reliability and looks are important. Nothing better than drawing back upon the heritage of vintage classics, the same way there are vintage inspired furniture. Raphaelite has some of the nicest looking HiFi products out of China, so again, you could draw inspiration from McIntosh and it would be hard to go wrong. All of the circuit diagrams and service manuals are well documented as well, with any IP long expired.

 

[TheWalkman]

I assume you mean “judging when it’s loud enough”… or are you launching another objectivist/subjectivist debate about SPL?

On volume, I’ll be subjective.

In a manner similar to Justice Potter Stewart commenting that he, “…knew porn when he saw it,” I know loud when I hear it and I don’t need to spend $1000 to tell me my ears were right!

 

[Herbert Shooler]

Great work Amir, you are a legend of Audio Truth

 

[Jimster480]

It is cool that the gauges are accurate... the product itself... I'm not sure where it would be installed or how it would be used normally. It looks like something that would be used for verifying the output of amps and calibrating them.

 

[GXAlan]

It is cool that the gauges are accurate... the product itself... I'm not sure where it would be installed or how it would be used normally. It looks like something that would be used for verifying the output of amps and calibrating them.

It was for classic double DIN car audio.

 

[Cbdb2]

It is cool that the gauges are accurate... the product itself... I'm not sure where it would be installed or how it would be used normally. It looks like something that would be used for verifying the output of amps and calibrating them.

A real meter or oscope would be used by a professional, not this expensive) toy. They would also be monitoring the current if they really wanted a power measurement.
With most speakers having impedance variations that are huge these are far from accurate. The high impedance at woofer resonance can be 40 ohms for a 4 ohm speaker and most of the power in music goes to the woofer. And the most important info for home audio from a meter is amp clipping which this dosnt show.

 

[GXAlan]

Before the era of in car GPS and steering wheel audio controls, you had stuff like SACD players in the car

And Denon had meters similar to Mcintosh but only rated to 50W

 

[phoenixdogfan]

Obviously quite expensive, especially considering the Fosi LC30, which was just reviewed in October, provides equally striking VU Meters plus amplifier and speaker switching, and only costs $150.

Still, it says McIntosh right there in their characteristic font, and has those BLUE LIGHTS! So if someone is really hankering to add this as a finishing touch to their rig, why would I judge?

As always, great review, Amir.

 

[ssashton]

Can't they just measure across a small in-line resistance to get the power accurately? Or am I missing something obvious?

 

[Sernyl]

The Fosi switch unit looks convenient to me.
The needles ? - Just for fun ;-)
Watt else ?

 

[Sokel]

A real meter or oscope would be used by a professional, not this expensive) toy. They would also be monitoring the current if they really wanted a power measurement.
With most speakers having impedance variations that are huge these are far from accurate. The high impedance at woofer resonance can be 40 ohms for a 4 ohm speaker and most of the power in music goes to the woofer. And the most important info for home audio from a meter is amp clipping which this dosnt show.

That's an onboard feature on new icepower modules,is just scaled analog outputs each reporting voltage and current per channel (4 total for 2-channels) .
It's both fun and educational watching how much they can differ.

 

[Martinvb]

Thanks @amirm to bring this odd piece of equipment to our attention. To me this can only serve as some kind of status symbol, just like most of this overpriced McIntosh gear. What is the use of a calibrated VU meter anyway? Music does not start to sound any better (or does it?). I must confess I bought the Fosi VU meter, but only for the option of remote switching between 2 amps or 2 sets of loudspeakers. To see some random movement of the huge meters is just eye candy (but then at a much more reasonable price).

 

[filo97s]

Yeah! With this price you can buy a system. But this is the star of the show. Now we have to wait a Chinese company checks the schematic to know understand what to do.

it's not a matter of schematics, it's not so difficult to build a functional and accurate power meter.
You pay that price solely for the brand and the legendary aesthetics. But it's fine, it's the same thing for luxury fashion.

 

[GXAlan]

To me this can only serve as some kind of status symbol, just like most of this overpriced McIntosh gear. What is the use of a calibrated VU meter anyway? Music does not start to sound any better (or does it?).

I sent this in to Amir.

It’s exactly that. Status symbol or more specifically, eye candy. It did help me understand exactly how many watts I was using when listening in my own setup. I previously had the MC2105 and MC2102 and the meters are a fun part of McIntosh products. It’s why the MC2100 just isn’t worth as much as the MC2105. When I sold off my McIntosh gear, and then Accuphase gear, I missed the “style” that the VU meters offered.

What we see with a lot of VU meters with labeled power output is just random numbers. It is nice to have accurate numbers if you are going to have numbers.

For speaker switching, I previously sent in three Luxman speaker selector.

Audio jewelry or “collectible” widgets like this:

75th Anniversary Limited Edition Ornament

A unique collectable for any McIntosh fan. Limited Edition - order yours before they are gone. Made in USA from fine pewter.

shop.mcintoshlabs.com

…are just things for fun, not driven by technical rationale. For those that celebrate Christmas and celebrate it with a home decorated tree, why pick the specific ornaments that you pick? That’s the rationale for picking some of the audio gear we pick…