Tag Archives: McIntosh

Asheville, Walnut Cove, Biltmore Forrest and Western North Carolina’s Audio and Home Theater specialists present Cane Creek AV and Paul McGowan – PS Audio, Intl

AC receptacles

For those of us with long memories here’s a flashback. Remember when preamps sported rear-mounted AC receptacles to power the rest of the stereo system?

The first memory I have of the rear-mounted AC receptacle was on my father’s McIntosh C28 preamplifier.

Note the use of switched and unswitched outlets. The idea was that unswitched outlets were for the power amp and switched outlets for tuners and tape decks.

What a grand idea. Run your entire stereo system including your power amplifier through a skinny 16-gauge 2-wire zip cord.

What was it Red Fox used to put his hands up towards the heavens and cry out?

“Elizabeth! They’re coming for me.”

Some innovations are better left in history’s dustbin.

Asheville, Walnut Cove, Biltmore Forrest and Western North Carolina’s Audio and Home Theater specialists present Cane Creek AV and Paul McGowan – PS Audio, Intl.

What is high end audio?

I had mentioned on our forums that there were several companies I did not believe aspired to produce high end audio products: McIntosh and B&O among them.

Ok, ok, I can see the fur flying already. Take a deep breath. This is not a put down. For the record, I admire both of the aforementioned companies: McIntosh for their superb build quality, measurement excellence and customer loyalty, B&O for style, innovation and leading edge ideas. But I don’t believe either aspires to produce high end audio products: McIntosh aspires to be the best built, greatest measuring luxury audio brand, while B&O the leader in style and innovation. Nothing wrong with either of those goals.

I don’t think there’s an industry standard, a qualifier to suggest this is high end audio, and that is not, so I wanted to open a dialog on the subject.

Where do we draw the line? What parameters do we use to define these categories so we’re all speaking a similar language? We can agree it isn’t price. There are plenty of pricey things that aren’t high end audio, as well as plenty of cheap things that are. We can likely agree it isn’t looks. There are plenty of snazzy products that don’t qualify, and an equal number that look like DIY kits, but few would argue they are not high end audio oriented.

No, I would suggest it is intent plus success at achieving a level of performance we can mostly agree upon (as Audiophiles). When the intent of a company is to design a product based on sound quality first, everything else second, I would suggest their intent is high end audio. On the other hand, if a company pushes specs and build quality first, it may be second to none, but that doesn’t a high end audio product make it.

Take a mass market product like Sonos. Their intent has never been sound quality that matters to Audiophiles (at least I can’t see it). They are the gold standard for usability, ease of operation, and hassle free music. But they are not high end audio, nor do they seem to aspire to be.

Or, take B&O. This is a great company, but their focus is style. I am guessing they style a product first, make it sound as good as possible second.

I am certain this is going to spark much debate, and that’s good. I didn’t write this as a put down to anyone or any company. No, quite the opposite. I own a Sonos system, I have owned B&O, I have lusted after McIntosh, and I am an Apple fan boy (and Apple is about as far away from high end audio as you can get).
But when it comes to high end audio there’s a line I draw that suggests this and that qualify – and these others don’t. And my standard is intent and performance. What were they trying to achieve and did they get close?

What’s yours?

McIntosh transformers

Yesterday’s post covered output transformers on tube power amplifiers and why they were needed.  It also covered the fact that IMHO transformers are the last thing I would add to the output stage of a solid state power amplifier because output transformers like this contribute so much to the sound quality of an amp – and not in a way that would make better sound, again IMHO.

Several of you asked “if that’s true, why then do some McIntosh solid state power amplifiers have transformers?”  My first thought was they must have added it to get a tube sound since the venerable McIntosh product line was tube based forever and a day.

I did a bit of research and found this not to be the case – it seems they were trying to solve a classic engineering/marketing problem with power amps – by using an output transformer – not something I would do but it’s worthy to note what they did and why.

What you want to accomplish when driving a loudspeaker is to develop a voltage across the loudspeaker terminals that is large enough to move the speaker drivers and make sound.  That voltage should be an exact, but larger, version of the musical signal fed into the amp.

In order to deliver voltage into a loudspeaker it takes current (power) and the combination of volts and current is expressed in watts.

Loudspeakers are tough to drive and take lots of power, as we’ve been discussing in these many posts.  They need this power because they’re using it to build a magnetic field in the speaker driver – a field big enough to move a heavy cone and push the air in the room around.  We express this need for power in Ohms: the lower the Ohm number the more power we need to move the cones and air.

As the Ohm number goes down, the need for power goes up proportionally.  So the power needed to make an 8 Ohm speaker produce sound in the room needs to double when the Ohms cut in half to 4 – and double again for 2 and so on.  Lower Ohms, higher power to achieve the same sound pressure.

As an amplifier manufacturer, we need to design power amplifiers to handle all practical loads a loudspeaker might present to us – and we never know what speaker our customers are going to try and power with our amplifiers.  Speaker load impedances vary from manufacturer to manufacturer and when they operate, they vary from their specified Ohm rating with the music as well!

This means a good power amp must be able to produce the same voltage regardless of the Ohm rating or the actual Ohm load of any loudspeaker.  In practical terms this can be daunting to a power amp manufacturer.  For example, our new power amp we hope will be shipping this summer produces 350 watts into 8 Ohms, 525 watts into 6 Ohms, 700 watts into 4 Ohms, 1050 into 3 Ohms and 1250 into 2 Ohms.  To be perfect, our amp should do 1400 watts into 2 Ohms and 2800 watts into 1 Ohm etc.  The numbers become astronomical at some point drawing far more power than even the wall AC power can supply.

From a practical standpoint, an amp the size we are going to produce should cover 95% of the loudspeakers, rooms and music types out there.

So back to the McIntosh solution.  The problem for any amplifier manufacturer is two fold: how do you rate the amplifier and what average power level do you design it for?

Most amps are rated at 8 Ohms, but most speakers are 4 Ohms.  From a marketing and practical standpoint I want to say our power amp is a 700 watt product – yet I will be held to the 350 watt rating even though that number is antiquated and less descriptive of the amp’s true use case.

What will be the average power used on this amp?  The FTC developed a rating system years ago that said whatever wattage level you wish to rate your amp at – the amp must be able to operate at 1/3 the rated power for 1 hour without shutting down – which ours will easily do at 1/3 700 watts.  Unfortunately, the magazines will still use the 8 Ohm rating.

Interesting issues – and what McIntosh did is designed their power amplifier to always run at the highest power rating it was capable of regardless of speaker load – through the use of an output transformer to couple the speaker.  This is exactly the opposite of what tube designers do – couple low impedance loudspeakers with high impedance tubes.

Using this method allowed McIntosh to run and rate their amps at one wattage level regardless of what impedance speaker is attached and so the amp always drove a very low load – and they were able to rate their amp at a very high wattage and get away with it because it did that same wattage for any impedance speaker.  Clever.

They solved one problem but created many others – through the sound quality degradation of an output transformer – as we’ve discovered over this series which brings me to my final point: if you put all your resources into solving a “problem” that your marketing department has, at the expense of your product’s sonic performance, you’ve probably done a bit of disservice to your customers and their musical enjoyment.

McIntosh has a very loyal following and one that is certainly deserved – they are a cool old company that has made wonderful products throughout the years.

I don’t agree with all their engineering decisions and I am sure they don’t agree with all of mine.

Paul McGowan – PS Audio, Intl