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post #31 of 52 Old 09-01-2013, 01:51 PM
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Originally Posted by saabracer23 View Post


Why do two tweeter, both with ferrite magnet, same voice coil material, aluminum domes with same moving mass, ect ect sound so different? Same with mids or woofers.

For one thing, the magnet, the voice coil material (is almost always copper or less frequently aluminum) etc. don't matter that much.

Moving mass primarily affects efficiency. In some cases people add mass to cones to cut efficiency and make the driver more compatible with small enclosures and extended bass bandpass. Depending on the circumstances, it doesn't affect other sonic parameters that much.

None of the parameters you mentioned affect things like high frequency resonances, which can a strong audible effects.
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post #32 of 52 Old 09-01-2013, 03:12 PM
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Anyone remember the Carver Challenge ?

The Carver Challenge, Where Bob Carver was given 48 hours to replicate the sound of high end amplifier using his mass market $700 amplifier.

http://www.stereophile.com/content/carver-challenge
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post #33 of 52 Old 09-01-2013, 04:33 PM
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I didn't read the whole article. i read the beginning and end. I stopped when I read "They were almost a perfect match, except for a slight difference in perceived depth and perspective." At that point the whole thing was meaningless. They didn't even bother to define perceived depth and perspective. Total garbage.
Just cruising likes this.
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post #34 of 52 Old 09-01-2013, 04:55 PM
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Originally Posted by FMW View Post

I didn't read the whole article. i read the beginning and end. I stopped when I read "They were almost a perfect match, except for a slight difference in perceived depth and perspective." At that point the whole thing was meaningless. They didn't even bother to define perceived depth and perspective. Total garbage.

Perceived depth, I would assume it means the layering of the sound from front to back... perspective, could be imaging from left to right.

At the end Bob Carver was able to replicate the sound of the "reference" amplifier. Even with biases were present as it was not a blind test and they wanted Bob Carver to fail, they (Stereophile) ended up in defeat
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post #35 of 52 Old 09-01-2013, 05:06 PM
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In a perfect world, all amplifiers should sound the same, as the goal of the amplifer is simply to amplify the signal, it should not add nor detract anything from the signal... sadly we don't live in a perfect world and compromises in manufacturing are made. Take for instance a capacitor or a resistor with a 5 percent tolerance, at maximum tolerances between 2 capacitors one being +5 percent from value and the other -5 percent, we have a total of ten percent difference from 2 parts being used in both channels, multiply that difference between all the parts in the amplifier. The more expensive amplifers uses parts with tighter tolereances, they even matched parts which are already very close in tolerance. Transistors are gain match to ensure balance between left and right channels, these are practices that the mass market manufacturer does not include in their process.
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post #36 of 52 Old 09-01-2013, 05:19 PM
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To the TS, I would go for the McIntosh or the Luxman, I personally go for used units as in the event that I may not prefer the way it "looks" with your loudspeakers, I could easily sell it and try something else...
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post #37 of 52 Old 09-01-2013, 06:06 PM
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Originally Posted by qguy View Post

In a perfect world, all amplifiers should sound the same, as the goal of the amplifer is simply to amplify the signal, it should not add nor detract anything from the signal... sadly we don't live in a perfect world and compromises in manufacturing are made. Take for instance a capacitor or a resistor with a 5 percent tolerance, at maximum tolerances between 2 capacitors one being +5 percent from value and the other -5 percent, we have a total of ten percent difference from 2 parts being used in both channels, multiply that difference between all the parts in the amplifier. The more expensive amplifers uses parts with tighter tolereances, they even matched parts which are already very close in tolerance. Transistors are gain match to ensure balance between left and right channels, these are practices that the mass market manufacturer does not include in their process.

Electronic circuits have a property called sensitivity, which is how sensitive the performance of the total piece of equipment is to variations in the given part. An amplifier is not equally sensitive to variations in all parts values. Many of the parts in an amplifier can vary over a wide range while having a negligible effect on performance. Some parts, especially the transistors can have important parameters such as their current gain that vary over a wide range - 2:1 or more while they are operating, and can themselves vary over a range of upwards of 6:1 while having a negligible effect on overall amplifier performance.

In fact transistors are not gain matched to ensure channel balance. Most transistors in AVRs are microscopic parts that are parts of op amp chips. The gain of amplifiers is usually set by a pair of resistors in the amplifiers inverse feedback path. Historically, the biggest detriment to amplifier gain matching were the analog mecchanical volume controls but for the past 10 years or so most AVRs have used electronic volume control chips that have tolerances on the order of 0.5%. or 0.05 dB.

http://www.cirrus.com/en/pubs/proDatasheet/CS3318_F1.pdf

http://semicon.njr.co.jp/eng/PDF/NJU72340A_E.pdf

If you actually ever get around to measuring the performance of real world audio amplifiers you will find that there are indeed slight variations in how nominally identical power amplifiers operate. It's easy enough to find differences in the gain and distortion that vary by a few percent per channel. IOW one channel might have 0.012% distortion under a certain set of circumstances, and another channel might have 0.011% distortion under the same circumstances. One channel might put out 98 watts under a certain set of circumstances while another channel might put out 99 watts.

Stage gains are usually set by 1% resistors, which means that channel gains will vary by up to 2% (0.2 dB) per channel but most channels will be within 0.5% (0,05dB). Again all trivial differences, but differences that can be measured reliability with modern test equipment.

I don't know where you obtained your ideas about amplifiers and parts sensitivities, but its not part of this world, and hasn't been for at least 40-50 years. For example the gains of even tubed amplifiers in amplifiers with any pretentions of quality going back into the 1960s and earlier were not allowed to be controlled by variations in the gain of individual tubes because the gain of tubes varied by dozens of percentage points over the life of a tube, or even over a few years of operation. Solid state equipment has always been designed to not have its performance controlled by the gain of individual transistors.

It is true that manufacturers graded transistors (and tubes) back in the early days, but the goal was not obtaining the right gain, but rather obtaining consistent bias points and desired distortion and noise performance.

In this day and age resistors with 1-2% tolerance are commodity parts and are not reserved for the most expensive equipment. Resistors with higher tolerances are generally not used for audio components but show up in electronic devices like test equipment.
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post #38 of 52 Old 09-01-2013, 06:09 PM
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Originally Posted by qguy View Post

Anyone remember the Carver Challenge ?

The Carver Challenge, Where Bob Carver was given 48 hours to replicate the sound of high end amplifier using his mass market $700 amplifier.

http://www.stereophile.com/content/carver-challenge

Yes, first published in 1985 which is about 30 years ago. Not all that relevant to audio in 2013.

His M 1.0 amplifier was somewhat innovative in those days, but these days its most distinctive circuit feature is called "Class G" and is commonly used in amplifiers used in the pro audio market. There are no secrets about it - its service manual with a full schematic is easily downloaded.

http://www.eserviceinfo.com/downloadsm/44806/Carver_m1.0%20T.html
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post #39 of 52 Old 09-01-2013, 07:57 PM
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Originally Posted by qguy View Post

In a perfect world, all amplifiers should sound the same, as the goal of the amplifer is simply to amplify the signal, it should not add nor detract anything from the signal... sadly we don't live in a perfect world and compromises in manufacturing are made. Take for instance a capacitor or a resistor with a 5 percent tolerance, at maximum tolerances between 2 capacitors one being +5 percent from value and the other -5 percent, we have a total of ten percent difference from 2 parts being used in both channels, multiply that difference between all the parts in the amplifier. The more expensive amplifers uses parts with tighter tolereances, they even matched parts which are already very close in tolerance. Transistors are gain match to ensure balance between left and right channels, these are practices that the mass market manufacturer does not include in their process.

Tolerances don't add or multiply in the way in which you describe. Caps are generally not in the signal path but instead are used in power supply filtering, where their exact value is not of concern.

Arny explained the other issues with your claims.

What's more, the manufacturing process for amps includes adjustable pots that are set in the factory to account for any resistor and transistor variations. Mass manufacturers most certainly do include these practices.

For every new thing I learn, I forget two things I used to know.
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post #40 of 52 Old 09-02-2013, 03:09 AM
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Quote:
Originally Posted by qguy View Post

In a perfect world, all amplifiers should sound the same, as the goal of the amplifer is simply to amplify the signal, it should not add nor detract anything from the signal... sadly we don't live in a perfect world and compromises in manufacturing are made. Take for instance a capacitor or a resistor with a 5 percent tolerance, at maximum tolerances between 2 capacitors one being +5 percent from value and the other -5 percent, we have a total of ten percent difference from 2 parts being used in both channels, multiply that difference between all the parts in the amplifier. The more expensive amplifers uses parts with tighter tolereances, they even matched parts which are already very close in tolerance. Transistors are gain match to ensure balance between left and right channels, these are practices that the mass market manufacturer does not include in their process.

Tolerances don't add or multiply in the way in which you describe. Caps are generally not in the signal path but instead are used in power supply filtering, where their exact value is not of concern.

The point needs to be made that the only place that capacitor tolerances have ever been an issue in audio gear is in equalization, crossover, filter, and tone control circuits. In modern AVRs all of those functions have been moved into the digital domain, so capacitor tolerances no longer matter as long as they are within 50-80 percent.
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post #41 of 52 Old 09-02-2013, 03:30 AM
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To the TS, I would go for the McIntosh or the Luxman, I personally go for used units as in the event that I may not prefer the way it "looks" with your loudspeakers, I could easily sell it and try something else...
I second that. There is a ready market for these two brands should they not work out for you.

"Bring out yer dead!".."Wait I'm not dead yet!"..(Sound Austrian here) "WRONG !!" (You know what happens next..)
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post #42 of 52 Old 09-02-2013, 04:54 AM
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AVR yes, but this is the 2 channel forum smile.gif Not all 2 channels gears have gone digital...
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Originally Posted by arnyk View Post

The point needs to be made that the only place that capacitor tolerances have ever been an issue in audio gear is in equalization, crossover, filter, and tone control circuits. In modern AVRs all of those functions have been moved into the digital domain, so capacitor tolerances no longer matter as long as they are within 50-80 percent.
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post #43 of 52 Old 09-02-2013, 05:19 AM
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To the TS, I would go for the McIntosh or the Luxman, I personally go for used units as in the event that I may not prefer the way it "looks" with your loudspeakers, I could easily sell it and try something else...
I second that. There is a ready market for these two brands should they not work out for you.

Both brands share a common feature - they are both examples of retro-technology. Other than slapped-on digital inputs, they are right out of the 1970s.
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post #44 of 52 Old 09-02-2013, 06:52 AM
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Originally Posted by arnyk View Post

Both brands share a common feature - they are both examples of retro-technology. Other than slapped-on digital inputs, they are right out of the 1970s.

Arnyk, ...Not that I expect it to change your opinion of McIntosh, but the MA6600 and all subsequent integrateds from McIntosh use digital processing for volume, bass/treble, balance, etc... That said, the meters and autoformers (found in most, but not all of their integrateds) are arguably "retro" features.
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post #45 of 52 Old 09-02-2013, 10:32 AM
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Both brands share a common feature - they are both examples of retro-technology. Other than slapped-on digital inputs, they are right out of the 1970s.

Arnyk, ...Not that I expect it to change your opinion of McIntosh, but the MA6600 and all subsequent integrateds from McIntosh use digital processing for volume, bass/treble, balance, etc... That said, the meters and autoformers (found in most, but not all of their integrateds) are arguably "retro" features.

It is not clear. The MA6600 Integrated Amplifier Brochure says:

"The Variable Rate Volume (VRV) control with Post Attenuator, a McIntosh innovation, provides exceptionally accurate tracking and very low noise operation. Bass, treble and balance functions are all digitally controlled and adjustable
via the MA6600 front panel or IR remote and bass and treble settings are automatically memorized independently for each input selection. All signal routing is accomplished with highly reliable, sealed electromagnetic switches."

Digital control is not the same as digital processing, and statements like "All signal routing is accomplished with highly reliable, sealed electromagnetic switches." describe plain vanilla analog audio signal processing techniques.
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post #46 of 52 Old 09-02-2013, 11:46 AM
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Should not really matter, as they should sound the same as any other amp with or without digital processing, Right ?
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post #47 of 52 Old 09-02-2013, 12:22 PM
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Quote:
Originally Posted by arnyk View Post

It is not clear. The MA6600 Integrated Amplifier Brochure says:

"The Variable Rate Volume (VRV) control with Post Attenuator, a McIntosh innovation, provides exceptionally accurate tracking and very low noise operation. Bass, treble and balance functions are all digitally controlled and adjustable
via the MA6600 front panel or IR remote and bass and treble settings are automatically memorized independently for each input selection. All signal routing is accomplished with highly reliable, sealed electromagnetic switches."

Digital control is not the same as digital processing, and statements like "All signal routing is accomplished with highly reliable, sealed electromagnetic switches." describe plain vanilla analog audio signal processing techniques.

Okay.. ..But are you expressing doubt that McIntosh's signal management - whether it's analog or digital - is sufficiently transparent? ..You often talk of the years and years of DBT's you have done involving both pricey and cheap gear - presumably this dates back to long before digital domain processing - and yet you've always come to the same conclusion, which is (paraphrasing of course) "if it measures flat, then it will be indistinguishable from other gear that measures flat provided comparisons are properly bias-controlled.' ..Is there some reason why Mac differs in this regard?

I can accept that Mac gear, for all of it's beauty and smooth operational feel, offers no audible advantage over cheaper gear. ..But I'm a little surprised if you're suggesting that, in DBT's, it would likely fair worse that cheaper offerings.. ..Which of Mac's specs would support this pessimism?
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post #48 of 52 Old 09-02-2013, 01:47 PM
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Originally Posted by syd123 View Post

Quote:
Originally Posted by arnyk View Post

It is not clear. The MA6600 Integrated Amplifier Brochure says:

"The Variable Rate Volume (VRV) control with Post Attenuator, a McIntosh innovation, provides exceptionally accurate tracking and very low noise operation. Bass, treble and balance functions are all digitally controlled and adjustable
via the MA6600 front panel or IR remote and bass and treble settings are automatically memorized independently for each input selection. All signal routing is accomplished with highly reliable, sealed electromagnetic switches."

Digital control is not the same as digital processing, and statements like "All signal routing is accomplished with highly reliable, sealed electromagnetic switches." describe plain vanilla analog audio signal processing techniques.

Okay.. ..But are you expressing doubt that McIntosh's signal management - whether it's analog or digital - is sufficiently transparent?

Not at all. But it appears to be highly limited compared to just about any modern AVR.
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..You often talk of the years and years of DBT's you have done involving both pricey and cheap gear - presumably this dates back to long before digital domain processing - and yet you've always come to the same conclusion, which is (paraphrasing of course) "if it measures flat, then it will be indistinguishable from other gear that measures flat provided comparisons are properly bias-controlled.'

What you left out is the ten or so years I ran a site called www.pcavtech.com that published tests I did on a variety of digital audio gear. Then there was www.pcabx.com where I provided a facility to do your own DBTs of a variety of audio products using just a PC with a good audio interface and headphones or monitor speakers.
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..Is there some reason why Mac differs in this regard?

Hidebound?
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I can accept that Mac gear, for all of it's beauty and smooth operational feel, offers no audible advantage over cheaper gear. ..But I'm a little surprised if you're suggesting that, in DBT's, it would likely fair worse that cheaper offerings.. ..Which of Mac's specs would support this pessimism?

None. My experience is that Mac gear does straight wire with gain pretty well, even the tubed stuff. Its just a very pricey and brain dead piece of wire.
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post #49 of 52 Old 09-02-2013, 01:48 PM
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Should not really matter, as they should sound the same as any other amp with or without digital processing, Right ?

Yup.
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post #50 of 52 Old 09-02-2013, 01:52 PM
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AVR yes, but this is the 2 channel forum smile.gif Not all 2 channels gears have gone digital...
Quote:
Originally Posted by arnyk View Post

The point needs to be made that the only place that capacitor tolerances have ever been an issue in audio gear is in equalization, crossover, filter, and tone control circuits. In modern AVRs all of those functions have been moved into the digital domain, so capacitor tolerances no longer matter as long as they are within 50-80 percent.

The question is why not use an AVR as the core of a 2 channel system? I know of no credible, technically sound answer to this question. Do you have one?

There used to be an answer to this question - it was about avoiding all the analog switches and controls and circuits related to the processing features that AVRs of the days had.

Then we started having AVRs with virtual switches and controls implemented via DSPs.

Problem solved!
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post #51 of 52 Old 09-02-2013, 01:58 PM
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Careful Arny, you might wake the audiophile Army. I said somewhere on the site that an audiophile would go nuts if asked to use an AV Receiver to drive a $20,000 pair of speakers but it would make perfect sense to me. The responses weren't positive. wink.gif
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post #52 of 52 Old 09-02-2013, 02:54 PM
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Should not really matter, as they should sound the same as any other amp with or without digital processing, Right ?

As long as you disable the good things that the DSP can do for you, yes they sound the same.
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