Mcintosh mc 462

[kevzep]

Static problem

No its not static, the meter randomly stops working, it sits at the rest position and does not work.
It never stops whilst the amplifier is operating, it will be when I power it up, sometimes is doesn't work.

I am familiar with the effect of electrostatic energy on meters, and this is not it.

 

[ron-c]

I'm just trying to figure out why they don't have the bridging/parallel option on the new amps, there has to be a logical reason...

Quad balanced amps are not designed to be bridged or paralleled. If they were this would compromise the Quad Balanced design.
Thanks,
Ron-C

 

[c_dk]

I think they are for all practical purposes bridged already....ie the speaker ground is floating above chassis ground and each output connection is being driven as a difference signal......

Looking at my MC501, compared to say a MC352, schematic this is quite evident even though these units were before the marketing slogan. The 501 has two drive feeds into the output transformer while the 352 has only 1.

I understand you can't bridge a mono channel amp, however it appears this mono amp does have a new/old transformer design....no longer a autoformer but much more like a tube amp where there is a phase inverter circuit.

 

[kevzep]

Quad balanced amps are not designed to be bridged or paralleled. If they were this would compromise the Quad Balanced design.
Thanks,
Ron-C

Yes I was actually just looking at the diagram for the Autoformer as I slide it out of the cabinet to repair this intermittent meter, the common seems to actually be "common" to the push and the pull amplifiers through the windings in Autoformer, with the common above ground.

So you have two balanced amplifiers driving that one autoformer, one feed is the push amplifier the other being the pull amplifier (Or High Side/Low side, or Negative side and Positive side), or at least thats what it looks like to me, so I can see how bridging a bridged Autoformer amplifier is not going to work, you'd be really messing with impedances and the likes, it just wouldn't work especially with the common tap on the input of the Autoformer.

I think they are for all practical purposes bridged already....ie the speaker ground is floating above chassis ground and each output connection is being driven as a difference signal......

Looking at my MC501, compared to say a MC352, schematic this is quite evident even though these units were before the marketing slogan. The 501 has two drive feeds into the output transformer while the 352 has only 1.

I understand you can't bridge a mono channel amp, however it appears this mono amp does have a new/old transformer design....no longer a autoformer but much more like a tube amp where there is a phase inverter circuit.

After looking at the Autoformer diagram on my MC452, there are two feeds going in, and two coming out, separated by a centre tap which is called Common, this common is not the negative speaker terminal as it is on a traditional amp, but rather there is the Negative amplifier terminals which are the black ones, and the Positive amplifier terminals which are the the red ones, nothing odd there, the thing which is the "gotcha" is the Autoformer winding is common to both channels, and this is where it gets tricky.

Interesting, I thought the MC352 was a "double balanced push pull" design....

 

[JosephH]

No its not static, the meter randomly stops working, it sits at the rest position and does not work.
It never stops whilst the amplifier is operating, it will be when I power it up, sometimes is doesn't work.

I am familiar with the effect of electrostatic energy on meters, and this is not it.

Hey Kev, how did the meter repair go? Fellow MC452 owners want to know!

 

[kevzep]

Hey Kev, how did the meter repair go? Fellow MC452 owners want to know!

I haven't had time to have look at it yet, I got close last week, I even pulled it out of the cabinet and it sat on the lounge floor for three days, but my lab is too busy with repairs.
I might get chance to do it next week....... i will let you guys know when I do it..

 

[capt.chaos]

The MC462 looks like a sweet amp. I would definitely buy one if I didn’t already have a MC452. At this point I will probably move to the MC611’s down the road.

 

[Ride06]

"There are few of us gung ho enough and demanding enough that will buy and place huge power requirement speakers into their home systems. Two reasons: speaker price and wife acceptance factor. Those that can afford the current huge monoblocks and line array trophy speakers also can afford the trophy wife that is not trying to control everything in a man’s life."

Read that to Mrs. she is thrilled to be a trophy wife!

 

[Bob the Tech]

The MC462 looks like a sweet amp. I would definitely buy one if I didn’t already have a MC452. At this point I will probably move to the MC611’s down the road.

I like all three of those too. I had the pleasure of listening to a MC462 yesterday after completing a repair on it. I dream of a pair of MC611s for my personal system, when I get those in the shop it's typically one at a time, not quite the listening experience I'm after.

 

[twiiii]

I have heard 452's and thought it was a big improvement over 402's. I have heard them push, Mac speakers, Magico speakers, magnaplanars, M&K S300, with subs, JBL briefly. It was a great amp. I assume a 462 improves on that. Over the years I have never seen an example from Mac where they might have taken a step backwards. Going from a 2255 to a 7270 seemed more like a horizontal step, and that might be said of the 2002 amp by some. It definitely couldn't tale the abuse that a 2255 could take. But thats not sound quality. When I first heard the 7106 I wasn't sure either. But it proved to be a real performer, just like the 206 and 207's I own have. I got one of my 207 to go into protection by listening to classical organ the other night where I had left the loudness control cranked up half way. But that was my fault. I haven't had that happen since I returned to Mac power in 13 years. If it had been using one of my Crown amps from the past I would have easily heard the distortion, but with power guard the sound never showed any sign of difficulty. If I had done that two my MC 2100's or 275's back in the 60's and 70's they would have both yelled uncle. Mc amps have definitely improved over the years.

 

[TSmith8605]

The Stereophile Review includes John Atkinson's measurements - for continuous power, he does not measure peak power.

McIntosh specifies the MC462 as being able to deliver 450Wpc (26.5dBW) into a load matched to the nominal output Autoformer tap. With clipping defined [by JA] as being when the THD+noise reaches 1%, fig.6 indicates that the MC462 exceeded its specification even with both channels driven, its 8 ohm output clipping at 516Wpc into 8 ohms (27.1dBW). The trace in this graph stops at 1%, as that is when the amplifier's protection was triggered. Into 4 ohms (fig.7), the McIntosh's 8 ohm output clipped at 720Wpc (25.6dBW). It's fair to note that I don't hold the wall voltage constant for this test; with both channels clipping into 4 ohms, the wall voltage had dropped from 121 to 115.4V. The MC462's 2 ohm output delivered 190Wpc (22.8dBW) with both channels driven into 8 ohms at 1% THD+N, 298Wpc with both channels driven into 4 ohms (21.7dBW, fig.8), and 536W (21.3dBW) with one channel driven into 2 ohms (fig.9). . .

. . .Summing up the McIntosh MC462's measured performance is easy: It is an extraordinarily well-engineered, exceptionally powerful amplifier.—John Atkinson

 

[SaturationPt]

Pretty much every McIntosh amp I have had the pleasure of owning has exceeded spec output at spec THD by at least 20%, my early gear that went to Mc clinics and the over-spec was documented (tube and solid-state), and later of course the reputable magazines would test and document the same.

I would be surprised if current production were any less over-built and capable.

 

[Two Socks]

Building a new set up Scored a 462 have to wait a bit for the Pre so I repurposed my C11 from the 225..
That being said they sound pretty damn good together.

 

[Onebean]

@Two Socks make sure that shelf is up to the task you have given it. I’d hate to see that C11 squashed!

 

[Two Socks]

@Two Socks make sure that shelf is up to the task you have given it. I’d hate to see that C11 squashed!

Was thinking the same thing. It was a temp set up. But I swapped it had to make the bottom shelf taller.