I said: the same curve shape. I didn't say anything about what the distortion would be. NO THD curve ever does this, so don't move the goal posts.
The measurements are not meaningless; if the distortion is drowned in the noise, and the noise is low enough to be inaudible, that's a valueable data point.
Aha! A feedback-phobe! This has nothing to do with the discussion at hand, but you couldn't resist, right? Now you gave yourself away!
Jan
My apologies to godfrey for the strong tone of my comments, it was a genuine mistake on his part ...
a.wayne, not lasting the pre-conditioning period has no bearing on being able to take correct measurements - as stated in many of the reviews this is intended to maximally heat stress the amp, assessing the capacity of the heatsinks. And in the case of the McIntosh "the rear-panel heatsinks were too hot to touch" from that pre-conditioning - the amp was well and truly up to temperature.
a.wayne, not lasting the pre-conditioning period has no bearing on being able to take correct measurements - as stated in many of the reviews this is intended to maximally heat stress the amp, assessing the capacity of the heatsinks. And in the case of the McIntosh "the rear-panel heatsinks were too hot to touch" from that pre-conditioning - the amp was well and truly up to temperature.
Really? When did I ever say that about their "listening"? Making stuff up again?
MacIntosh has a long tradition on using autoformers, I have an old MC2105 somewhere that also uses a big chunk of iron in the output stage. I always thought they did so at the time to keep tricky output devices into their SOA, but apparently they carry on the tradition even till today, even though better output devices exist than in the time of the 2105.
There are obviously weight and cost penalties, so I can understand why other manufacturers did not follow their example.
There are obviously weight and cost penalties, so I can understand why other manufacturers did not follow their example.
Those are highly regarded speakers 45k worth , we have gone thru enuff Mac stuff to comment , these were not off the cuff comments...
What happened to the integrity trip , all amplifiers go thru a pre-conditioning test before bench measurements, this amp failed the preconditioning test , making its result uncomparable to others that did , what part are you not getting Frank ..?
It failed again at the lower level of 30 watts , obvious to me why it sounds hard When driven..
There is a significant expense associated with them. Likewise, the hack designers that are common in fashion audio wouldn't know how to use them properly.
BTW, Roger Russell did some fine speaker designs for Mac. If I'm not mistaken, one of our regular participants here also did some speaker design for them.
Innocent question here....
I noticed the Mac can deliver over 700W into 8 Ohms, which corresponds to over 200V pk-pk. That sounds like it could be a serious shock hazard. Are there any safety-related legal requirements here e.g. regarding the speaker connectors?
Not picking on Mac here - this obviously applies to any very high power amp, as well as the old "100 Volt" PA systems.
I noticed the Mac can deliver over 700W into 8 Ohms, which corresponds to over 200V pk-pk. That sounds like it could be a serious shock hazard. Are there any safety-related legal requirements here e.g. regarding the speaker connectors?
Not picking on Mac here - this obviously applies to any very high power amp, as well as the old "100 Volt" PA systems.
So you have heard the McIntosh speakers sounding awesome with your favorite amplifier.
Your welcome. If they don't know it, they can use L and C to figure it out.
Z = sqr(L/C)
Some vendors don't know how to measure inductance correctly, so be careful here.
If it's simple parallel wires, it's probably between 100 and 150.
Ah, ok. Like a rose by any other name..
In industrial apps, anything over 50 volts is a concern. Touching a voltage over that is considered "working hot".
Really... You can't make this stuff up
.jn
I believe the Low Voltage Directive in Europe calls everything above 40V a hazard. Speaker posts on amps here have to be insulated.
BTW speaker connections now have to blocked for 4mm banana's on the grounds that otherwise people might connect mains plugs to the speakers or amps...
Can't see what good (or bad) that would do, but hey, I failed bureaucracy 101 ...
Edit: The LVD is also 50V.
Jan
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Good analogy . Steve Eddy's reference to USAF training youtube video teaches autotransformers as a sub class both variac anf rf one . Thus my musing about what we call things and how we are classing them . It ain't Rocketsurgery .Your welcome. If they don't know it, they can use L and C to figure it out.
Z = sqr(L/C)
Some vendors don't know how to measure inductance correctly, so be careful here.
If it's simple parallel wires, it's probably between 100 and 150.
Ah, ok. Like a rose by any other name..
In industrial apps, anything over 50 volts is a concern. Touching a voltage over that is considered "working hot".
Really... You can't make this stuff up
jn
I guess can calculate the characteristic impedance because my speaker cable is Tara Labs Space & Time II (not expensive old cable) and uses several wires inside each rail.
An externally hosted image should be here but it was not working when we last tested it.
SY, I never understood your precise meaning of the use of the word:"Chimps" in regard to Stereophile reviewers. I presumed that this meant that they were somehow 'chimp-like' in their behavior and discernment. Sorry if I missed the use that you made of the word.
As far as the JC-1 'oscillation' is concerned, I am surprised that one of my competitors, who I barely know, would tell you about what its cause was, and not me. I did ask John Atkinson, himself, and he did not seem to know the specific reason. I have my suspicions that it might be a floating ground or a faulty switch setting. I have never personally found this oscillation in my tests in my lab, or in the field with the JC-1's.
Why don't you give me an answer to this mystery since you appear to have it?
As far as the JC-1 'oscillation' is concerned, I am surprised that one of my competitors, who I barely know, would tell you about what its cause was, and not me. I did ask John Atkinson, himself, and he did not seem to know the specific reason. I have my suspicions that it might be a floating ground or a faulty switch setting. I have never personally found this oscillation in my tests in my lab, or in the field with the JC-1's.
Why don't you give me an answer to this mystery since you appear to have it?
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