McIntosh with Magnepan not a good match?

[miatadan]

Originally Posted by Charles

As far as taps are concerned I would always go with the speaker's recommended impedance. With Magnepan I believe this is 4 ohms. Modern Mac amps have enough current capacity to drive almost any speaker. I believe that in general Magnepans are forgiving speakers with the added benefits of great imaging, sound staging, openess, and detail. However, as with all planar designs dynamics can be a problem. Mac may not offer the last little bit of dynamics that fine direct coupled amps do. In addition Macs may not possess that last little bit of detail as fine direct coupled amps do. If I were matching an amp to a Magneplaner Mac would not be my first choice, but I would still expect the combination to sound very good.

this is post from other forum that I read that I was surprised about:

zuluwarrior0760
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Re: McIntosh power amplifier with Magnepan's...
« Reply #3 on: 19 Nov 2015, 05:00 am »
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I've heard Magnepan 3.7s twice with McIntosh amplifiers (once 250wpc and the other time 300wpc)

I tried both 4 and 8 ohm taps and I heard very little difference, which in itself tells me McIntosh
amps are not a good match for Maggies......they just don't make them come to life.......

The whole autoformer thing puts what should be a powerhouse in tube amp territory........

I have owned 3.7s for over 3 years now and have heard them on no less than 15 amps that I have
owned or friends have brought over for late night listening parties and I have found
that there are many amplifiers that sound very good with Magnepan 3.7s, but only a couple
proved to be a great pairing:

Bryston 7bsst2s and Bryston 28bsst2's

I will say that last week I had the chance to try Zesto's brand new Eros amps @ 150wpc
and they sounded great with the maggies, but they didn't have the headroom I had
grown accustomed to with my Bryston 7's.......because the Bryston's had 6 times the juice
into 4 ohms versus the Zestos......and the 28s I am getting ready to go with will have
double that .......

[damacman]

One really has to delve into the details of why McIntosh originally elected to employ autoformers with its solid state offerings to fully understand why some naysayers have no earthly idea of what they speak. To date, the MC2505 remains an amplifier that can shame current offerings from competitors.

Your MC302 could, within reason, drive nearly any speaker you could connect to its 8 Ohm taps - and without strain. The McIntosh design makes it possible to drive loads that would cause other amps to go into protection via the inclusion of 4 and 2 Ohm taps.

I'm not at all surprised that your MC302 drives your "4 Ohm" Magnapans better from the 8 Ohm taps. In this configuration, the amplifier can deliver greater current than from the 4 Ohm taps and easily double the power to the speakers when doing so.

Traditional OTL power amps can also double output power as impedance is halved. So can every McIntosh autoformer equipped amplifier, when using the 8 Ohm taps. The same can be said for 2 Ohm loads connected to the 4 Ohm tap, 1 Ohm loads connected to the 2 Ohm taps, etc. Traditional OTL designs have a very difficult time running 2 Ohm loads without significant current limiting and 1 Ohm loads are all but impossible. OTL designs capable of both certainly do exist but come at a premium. The problem is practicality. What good is it to own an amp capable of 300W/ch at 2 Ohms if you intend to use it with 8 Ohm speakers? [Using the math above nets 75W/ch at 8 Ohms.] Conversely, a McIntosh amp rated at 300W/ch at 2 Ohms can also make 300W/ch at 4 Ohms and at 8 Ohms! This is one of the main reasons I buy McIntosh amps - no matter the speakers you buy, a McIntosh amp with autoformers is poised to deliver its rated power to them with no funny business required. Synergy can be achieved in nearly every case.

Lower impedance loads create additional heat which can in turn reduce life of the electronic components themselves - a stark reality in all OTL designs, no matter the cost. McIntosh amps equipped with autoformers avoid that altogether by offering multiple taps as the outputs work the same driving a 2 Ohm load from the 2 Ohm taps as when driving 8 Ohm speakers from the 8 Ohm taps.

The power supplies in McIntosh amps are seriously overbuilt, beginning with the power transformer. The power supply is the determining factor on how well a given amp is at delivering current - the real story in driving difficult loads. And then there's phase angle ... the reality that current and voltage are often out of phase with one another when driving a loudspeaker playing music. Again, the power supply design is the determining factor at just how well a given amp performs in regards.

Let's just say that I've driven very difficult loads with my Mc amps when the need arises. Not only did they sail through unscathed, but they live to play another day.

To the naysayers, I say nonsense. Enjoy your combo.

[Weirdcuba]

Well put, damacman.

[ehoove]

Originally Posted by damacman

One really has to delve into the details of why McIntosh originally elected to employ autoformers with its solid state offerings to fully understand why some naysayers have no earthly idea of what they speak. To date, the MC2505 remains an amplifier that can shame current offerings from competitors.

Your MC302 could, within reason, drive nearly any speaker you could connect to its 8 Ohm taps - and without strain. The McIntosh design makes it possible to drive loads that would cause other amps to go into protection via the inclusion of 4 and 2 Ohm taps.

I'm not at all surprised that your MC302 drives your "4 Ohm" Magnapans better from the 8 Ohm taps. In this configuration, the amplifier can deliver greater current than from the 4 Ohm taps and easily double the power to the speakers when doing so.

Traditional OTL power amps can also double output power as impedance is halved. So can every McIntosh autoformer equipped amplifier, when using the 8 Ohm taps. The same can be said for 2 Ohm loads connected to the 4 Ohm tap, 1 Ohm loads connected to the 2 Ohm taps, etc. Traditional OTL designs have a very difficult time running 2 Ohm loads without significant current limiting and 1 Ohm loads are all but impossible. OTL designs capable of both certainly do exist but come at a premium. The problem is practicality. What good is it to own an amp capable of 300W/ch at 2 Ohms if you intend to use it with 8 Ohm speakers? [Using the math above nets 75W/ch at 8 Ohms.] Conversely, a McIntosh amp rated at 300W/ch at 2 Ohms can also make 300W/ch at 4 Ohms and at 8 Ohms! This is one of the main reasons I buy McIntosh amps - no matter the speakers you buy, a McIntosh amp with autoformers is poised to deliver its rated power to them with no funny business required. Synergy can be achieved in nearly every case.

Lower impedance loads create additional heat which can in turn reduce life of the electronic components themselves - a stark reality in all OTL designs, no matter the cost. McIntosh amps equipped with autoformers avoid that altogether by offering multiple taps as the outputs work the same driving a 2 Ohm load from the 2 Ohm taps as when driving 8 Ohm speakers from the 8 Ohm taps.

The power supplies in McIntosh amps are seriously overbuilt, beginning with the power transformer. The power supply is the determining factor on how well a given amp is at delivering current - the real story in driving difficult loads. And then there's phase angle ... the reality that current and voltage are often out of phase with one another when driving a loudspeaker playing music. Again, the power supply design is the determining factor at just how well a given amp performs in regards.

Let's just say that I've driven very difficult loads with my Mc amps when the need arises. Not only did they sail through unscathed, but they live to play another day.

To the naysayers, I say nonsense. Enjoy your combo.

I disagree, but will acquiesce on this issue, Maggies like high current amps, not autoformer limiting ones. Also the autoformer is the last component in the chain, not the power supply.
Regards,
Jim

[damacman]

Jim,

In the interest of learning from one another, please tell me how the autoformer could limit current to the load if the amplifier was connected properly? I can think of one way - using the incorrect tap given the load. IE, running an 8 Ohm load via the 2 Ohm taps.

My MC500 is rated at 112A/channel. My MC2600s are rated at 100A/channel. An MC452 is rated at 75A/channel. Do these amplifiers not qualify as "high current"?

[ehoove]

I speak of the Vintage models, not the current or more modern amps. I only have experience with the earlier models which I could never get to sound open or fast on the various Magnapans I have owned no matter what taps were employed. That being said the vintage Mac's sounded fine on the conventional speakers I have owned. This is not a put down on McIntosh products, just the pairing of Vintage Mac's with autoformers and Magnapan's IMHO I even had them gone through by Terry D to make sure they were updated to spec, and was still disappointed in the pairing. (MC2100's run in both Stereo and Mono modes.)
Regards,
Jim

[Charles]

Speaker-amp matching is very important. Most folks that buy Magneplanar are cost conscious as we all are. Modern Mac amps are capable of doing, IMO, a very good job but not the best. Take the 601 with the comparable Classe mono amp. There is little question in my mind that I would go with the Classe or a competitor of Classe that is OTL over the 601. I think you need plenty of watts and an amp (OTL) with plenty of current at low impedance to make a Magneplanar sing. They are great speakers when properly driven. I thoroughly enjoyed my Magneplanars. If the Thiel CS5 had not come out I might be owing a top of the line Magneplanar with a Krell to this day.

[Mikado463]

Originally Posted by damacman

I'm not at all surprised that your MC302 drives your "4 Ohm" Magnapans better from the 8 Ohm taps. In this configuration, the amplifier can deliver greater current than from the 4 Ohm taps and easily double the power to the speakers when doing so.

Correct me if I'm wrong but I thought the power output remained the same regardless of which tap one selected ?

The problem is practicality. What good is it to own an amp capable of 300W/ch at 2 Ohms if you intend to use it with 8 Ohm speakers?

That answer is simple, for most speakers (certainly Maggies) have a 'nominal' impedance rating, we're not talking about driving a simple resistor here.

[damacman]

Originally Posted by ehoove

I speak of the Vintage models, not the current or more modern amps. I only have experience with the earlier models which I could never get to sound open or fast on the various Magnapans I have owned no matter what taps were employed. That being said the vintage Mac's sounded fine on the conventional speakers I have owned. This is not a put down on McIntosh products, just the pairing of Vintage Mac's with autoformers and Magnapan's IMHO I even had them gone through by Terry D to make sure they were updated to spec, and was still disappointed in the pairing. (MC2100's run in both Stereo and Mono modes.)
Regards,
Jim

Gotcha. I own MC2300s as well, the MC2100s bigger brother. I can tell you with certainty those amps are a little more difficult to achieve good synergy with than more current offerings.

Originally Posted by Charles

Speaker-amp matching is very important. Most folks that buy Magneplanar are cost conscious as we all are. Modern Mac amps are capable of doing, IMO, a very good job but not the best. Take the 601 with the comparable Classe mono amp. There is little question in my mind that I would go with the Classe or a competitor of Classe that is OTL over the 601. I think you need plenty of watts and an amp (OTL) with plenty of current at low impedance to make a Magneplanar sing. They are great speakers when properly driven. I thoroughly enjoyed my Magneplanars. If the Thiel CS5 had not come out I might be owing a top of the line Magneplanar with a Krell to this day.

Although the Classe amp is obviously a stellar performer, I don't understand why the MC601s couldn't perform equally as well when using the 8 Ohm taps.

Originally Posted by Mikado463

Correct me if I'm wrong but I thought the power output remained the same regardless of which tap one selected ?



That answer is simple, for most speakers (certainly Maggies) have a 'nominal' impedance rating, we're not talking about driving a simple resistor here.

See my explanation above about using the 8 Ohm taps and my reference of phase angle - loudspeakers are a combination of capacitive, inductive, and resistive loads and most assuredly do not load an amp like a purely resistive load. This is where power supply design is most critical - to maintain output voltage as the load varies among these factors.

[damacman]

I did look up the current rating of the MC302. McIntosh specifies 60A/channel. It looks like McIntosh has increased the rail voltage in this amp (and significantly) in comparison to say an MC2300. What McIntosh doesn't say is how they measure that in this model ... But, it's safe to say that number was taken from the 8 Ohm taps driving a very low impedance load.

When a manufacturer gives you a number like that, it's to showcase the ability of the power supply.