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McIntosh MC 427 Amplifier Review

Rate this car amplifier:

  • 1. Poor (headless panther)

    Votes: 1 0.7%
  • 2. Not terrible (postman panther)

    Votes: 1 0.7%
  • 3. Fine (happy panther)

    Votes: 36 23.5%
  • 4. Great (golfing panther)

    Votes: 115 75.2%

  • Total voters
    153

voodooless

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This is one hell of a budget way to own a real McIntosh amp!

Get yourself one of those matching Chinese knockoff cases, a 14v 500W SMPS, and you almost have the real deal :cool:
 

OldHvyMec

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I've ran several Mcintosh systems in cars and heavy equipment. They hold up in very harsh conditions and work exceptionally well in 24VDC systems.
The problem with all low voltage systems is LOW VOLTAGE. The trick with all 12VDC systems is a great alternator 2-400 amps, Great batteries with a lot of
space under the plates (if you use lead acid), large quality copper cables, a lot of stored available power for big big bass (cap banks) and heavy, quality
terminal ends joined to the cables with extremes pressure. Every terminal end needs to be treated with enhancers, @Loctite, and sealed, especially in
heavy equipment and marine applications.

I never had a single issue with any of the Mcintosh amps I used in cars or equipment. A boat and an excavator were swamped but they don't count.
I wasn't in them and amps had nothing to do with "Stupid". No they didn't survive going under water the two times I was called. Shame they were
never cheap units. I know a lot of guys hot rod and doll them up too.

I've installed a few Valve amps in pandraggers. It was always Mcintosh amps with Alpine or Mcintosh head sets. It's actually where I got a pair
of 24c MC60 gold cases polished to perfection in terms of jewelry. I still have them for the one off Mcintosh refurbish.
Pot the transformers, powder coat the transformer covers and get an inverter. Mike Samra can get close to 100 watts per. They can push an 18"
pro speaker to ear bleeding SPL and look really cool in a rumble seat with a reel to reel mock up.

I quit doing it a while back I sold my lead sled. 51 Merc Coupe, 429 SCJ.
Reminded me of a M60 tank and just about the same fuel mileage, down hill
with a tail win.

I'll take a Roller with a Blaupunkt that will work. I suppose we could lower it a tad. :)

A plus for an old Mac. Thanks Amir! Nice review. They are one of the better sounding AB for sure if you're sensible with the load.
The source is alway the problem in a car. They love memory sticks and touch screens. I like gear levers and arming switches. LOL

Engage the overthruster, we need more power (in Arnold's voice).

Happy Holiday.

Regards to all
 

MediumRare

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That looks like a bit of a return to form and I appreciate that. For the money, I think a new Corvette could compete though and, of course, we have the "legendary" Maserati reliability and resale value.
I’ll keep my 718S anyway
 

CleanSound

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Now I wonder how well does modern McIntosh home, solid state amps measures.
 

Sokel

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Now I wonder how well does modern McIntosh home, solid state amps measures.
Around -100/-105db THD (5 to 500 watt) here:

100-105db.PNG


And THD+N vs freq is nice too:

1701893912932.jpeg

8 ohms(left channel blue, right red), 4 ohms (left cyan, right magenta).

 
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Labjr

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So Class AB stuff from the old days wasn't that bad after all. I wonder how noisy it is when powered from the typical electrical system in a vehicle. Or maybe that's how you test them?

BTW, I wonder if Hypex or Purfi plan to get into car amplifers? Doesn't seem like it would take much more than redesigning power supplies for 12V.
 
Last edited:
OP
amirm

amirm

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So Class AB stuff from the old days wasn't that bad after all. I wonder how noisy it is when powered from the typical electrical system in a vehicle. Or maybe that's how you test them?
I don't but I did parallel my lab supply to keep charging the battery and it had no impact on the measurements.
 

Chrispy

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So how big an opening in one's dash do you need for something like this? Definitely an impressive piece for a car....but could possibly just attract thieves otoh.
 

Robbo99999

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My thoughts on the review: fair enough but does SINAD really matter in a car stereo where you have lots of background noise (& other issues/imperfections). Sure, it has to be measured here on ASR (SINAD), but in this application I don't think it matters a great deal. For sure I'd say a lot of the other measured parameters of this amp were useful to know. I can't vote in this poll though as I don't know what's really required in the car hifi world. Interesting to see it tested.
 

DonR

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My thoughts on the review: fair enough but does SINAD really matter in a car stereo where you have lots of background noise (& other issues/imperfections). Sure, it has to be measured here on ASR (SINAD), but in this application I don't think it matters a great deal. For sure I'd say a lot of the other measured parameters of this amp were useful to know. I can't vote in this poll though as I don't know what's really required in the car hifi world. Interesting to see it tested.
When this amp was made I would have said: no, the figure is just so they could advertise as such and it has no real-world practical use. Now, however, cars are becoming ever more quiet inside thanks mainly to electrification and advances in soundproofing so today it now has a use case or at least a better argument for one.
 

id.ray

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I for one would love to see more McIntosh stuff tested here. I do understand it is very expensive and a lot of their portfolio is out of the realm for most. However some is within reach especially in the used market and. I have been hoping to catch either a pair of MC830s or one of the Mc462 used after seeing @hardisj review on Erin's Audio Corner. I think it would be perfect for My KEF Reference 5's and a great replacement for my Yamaha M60

 

Robbo99999

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When this amp was made I would have said: no, the figure is just so they could advertise as such and it has no real-world practical use. Now, however, cars are becoming ever more quiet inside thanks mainly to electrification and advances in soundproofing so today it now has a use case or at least a better argument for one.
That's a good idea re electrification & lower noise, but with the levels of SINAD we're talking then surely it's miniscule in comparison to even the quietest of quiet electric vehicles whilst driving - road noise, etc, (petrol engine & exhaust obviously being only one part of motoring noise).
 

id.ray

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@amirm Is there a reason you didn't try and run it the bridged configuration?

 

mhardy6647

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Not even obscenely expensive.
I'm surprised -- and impressed.
 

Labjr

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Seems car stereo amps are designed to deliver more power into lower impedance loads than home amplfiers. Is that because users tend to bridge and parallel car speakers?
 

Labjr

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I have a hunch McIntosh solid state amps are probably among if not the best measuring high power AB amps in production - just a hunch though

McIntosh seems to use output transformers in their flagship amps. I wonder how they measure? I'd like to see Pass Labs XA series amps measured too.
 

Doodski

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Seems car stereo amps are designed to deliver more power into lower impedance loads than home amplfiers. Is that because users tend to bridge and parallel car speakers?
The hardercore car audio enthusiasts want 2 Ohms load so they get more wattage.
 
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