Digging back on amplifier topology, I see several comments in reviews and ads about Emotiva's "short signal path" and that is is supposed to do some wonderful thing for the sound. Does anyone know anything about their designs? Is it different, or just Madison Av. engineering. Some folks like their amps quite a bit. Just curious.
I have herd two digital switching amps, one generic AVR, one trying to be high end. I did not like either. Hard to put a finger on it, but they are different.
Think about digital photos. Even after we got above 16M, a digital and a film photo are different Neither right, neither wrong. Different. Small differences in contrast or tint due to IR sensitivity? Shape and overlap of the pixels Not a clue. I prefer the film. Digital tends to look "too real" to me. The generic AVR sounded like a cheap AVR. The high end amp was just not comfortable. Too real? Too quiet? Different harmonic distortion distribution?
Think about digital photos. Even after we got above 16M, a digital and a film photo are different Neither right, neither wrong. Different. Small differences in contrast or tint due to IR sensitivity? Shape and overlap of the pixels Not a clue. I prefer the film. Digital tends to look "too real" to me. The generic AVR sounded like a cheap AVR. The high end amp was just not comfortable. Too real? Too quiet? Different harmonic distortion distribution?
In my experience, and I have not heard Emotiva's units, most digital switching amps are, as you say, different.
Regarding short signal paths, well, isn't that what everyone should be doing anyway? And in digital switching amps, the whole kaboodle is already miniature, I honestly don't think shortening it by another 1 mm is going to produce a revelation.
Excellent analogy.
And among several digital cameras, about the same range of technology, pixels and money, each one will have its very own and unique hue. As an example, I find Sony cameras to lean towards shades of brown and green, HP's offerings tend to go a bit brown and don't do red very well, etc. Reminds me of audio.
Over the years, I have settled on Olympus cameras for two reasons: 1) Their colour renditions is, to my eyes, the most faithful to the original, except for violet, which is fortunately very rare in real life, and 2) even though Canon "invented" macro ohotography, Olympus is particularly good at it and better then most of the rest, and I happen to need it.
I suspect about the same will apply to class D amps. They may be built around the same chip, but the periphery has some say in it all. Change any one of the variables beside the chip, and you will likely get a somewhat different sound in the end. That difference may or may not please any one of us, so in the end, it will all come down to personal taste.
I won't be happy with class D until I can sit down and design something that works . I never had one work properly yet . OK I can buy a chip as anyone can , it is not the same .
Earlier this year I took some valves and things left to me by my late brother . From scratch I taught myself . It had to be that way because the familiar valve designs are not my cup of tea . After 6 months I came up with something that pleases me and is nothing like the designs others use . Mildly radical . Did have transistors in it for most of it's life , even they have gone and have accepted 6 db worsening in distortion at 80% power ( not below ) . Many of my fears were groundless and all was logical although no book helped with the . A comment DF 96 made helped as it got me out of fairy story world ( short signal path is one , good ground point is it's accurate name ) . My problem is to do a class D that way has not been possible . I would be happy to have 100 watt for a sub-woofer and feel a NE555 should be good enough .
Class D like digital is an extra layer of complexity at the very best . The Hypex looks like a conventional amp mostly ( or comparator ) . As I understand it the dead band dictates plenty . I guess as close to latch up as one dares . Creek amps latched up Mike told me . He specified a certain gain Darlington , his supplier thought he would upgrade Mike FOC and disaster ensued ( on switch on I think ) . Sounds unlikely but interesting .
Earlier this year I took some valves and things left to me by my late brother . From scratch I taught myself . It had to be that way because the familiar valve designs are not my cup of tea . After 6 months I came up with something that pleases me and is nothing like the designs others use . Mildly radical . Did have transistors in it for most of it's life , even they have gone and have accepted 6 db worsening in distortion at 80% power ( not below ) . Many of my fears were groundless and all was logical although no book helped with the . A comment DF 96 made helped as it got me out of fairy story world ( short signal path is one , good ground point is it's accurate name ) . My problem is to do a class D that way has not been possible . I would be happy to have 100 watt for a sub-woofer and feel a NE555 should be good enough .
Class D like digital is an extra layer of complexity at the very best . The Hypex looks like a conventional amp mostly ( or comparator ) . As I understand it the dead band dictates plenty . I guess as close to latch up as one dares . Creek amps latched up Mike told me . He specified a certain gain Darlington , his supplier thought he would upgrade Mike FOC and disaster ensued ( on switch on I think ) . Sounds unlikely but interesting .
Camera sensors are like speakers, none are perfectly accurate (and film was the same - look at Agfa vs Kodak). You have the gamut limitations of 3 colour sensing (why don't they do 4 colour like the Sharp TVs?), differences in the filter passbands and the the output dsp tweaking, which often exagerates colour saturation because people like itExcellent analogy.
And among several digital cameras, about the same range of technology, pixels and money, each one will have its very own and unique hue. As an example, I find Sony cameras to lean towards shades of brown and green, HP's offerings tend to go a bit brown and don't do red very well, etc. Reminds me of audio.
'Short signal paths' are fine, provided that the whole recording-reproduction system includes no microphone transformers, no long cable runs from studio to equipment racks, no OPTs, no equalisers, no over-the-air broadcast etc. Otherwise, competently-designed signal paths are sufficient.
To my way of thinking the ground being low impedance is all important . As said cables are an inconvenient necessity . Balanced helps . A short path is mostly irrelevant if the inductance and capacitance it what the design demands . The short signal path people imply there is a time delay . I can't see it in audio . One might be forced to have a short signal path to get the hum performance wanted . That might be true . Naim told me that they had no idea where exact 0V was in their design ( a good way to say it ) . Half way up the so called SNAIC cable was Robin's best guess he said with a chuckle .
I think if you go back a few thousand posts, you will find considerable views about different sounding amps. In my search for understanding aided by the relentless push form some of the folks here who design amps for a living, I was able to understand how differences in topology of various "good" amps is audible. I went as far as changing the dominant pole compensation in a Hafler 120 from VAS output loading to transitional miller and my wife ( golden ears) could immediately hear the difference. Once I improved my speakers sufficiently I was immediately hooked on HCA amps over the 9 and 10 series Rotel that were more tolerant on the lessor speakers. I sold all my Rotels.
Could it be we have yet to experience a "good" class D amp? I guess I would agree as what I have heard is different and I don't care for them. I prefer the analog Rotel to the class D, and I prefer the Parasounds, Arragon, Acrus and several others to the Rotels. I prefer the Marantz mid level receivers to the Pioneer class D in the same price range. I have only heard a couple higher end class A amps and yes, they were very good, but were quite low power and were not a good match to my speakers. Better than a good class AB? I would not swear to it as you suggest, as I believe money is better spent on better speakers. We have of course all herd bad class everything amps.
I think if you go back a few thousand posts, you will find considerable views about different sounding amps. In my search for understanding aided by the relentless push form some of the folks here who design amps for a living, I was able to understand how differences in topology of various "good" amps is audible. I went as far as changing the dominant pole compensation in a Hafler 120 from VAS output loading to transitional miller and my wife ( golden ears) could immediately hear the difference. Once I improved my speakers sufficiently I was immediately hooked on HCA amps over the 9 and 10 series Rotel that were more tolerant on the lessor speakers. I sold all my Rotels.
Could it be we have yet to experience a "good" class D amp? I guess I would agree as what I have heard is different and I don't care for them. I prefer the analog Rotel to the class D, and I prefer the Parasounds, Arragon, Acrus and several others to the Rotels. I prefer the Marantz mid level receivers to the Pioneer class D in the same price range. I have only heard a couple higher end class A amps and yes, they were very good, but were quite low power and were not a good match to my speakers. Better than a good class AB? I would not swear to it as you suggest, as I believe money is better spent on better speakers. We have of course all herd bad class everything amps.
There are many good class D amps, they are used in subwoofers - where they belong. Until semiconductor industry will be able to produce high current (like 100 amps) switches operating at 5 MHz frequency and above (range of DSD128) switch mode amplifiers can be only well siuited for frequency limited application.
Evening Gents.
I'm enjoying the discussion and I thought I'd pop a question.
I am curious if amplifiers with high current capabilities into difficult loads technically have a advantage over other discrete component amps in SQ. Or is this HCC Harman Kardon thing a marketing word only?
I have a Harman Kardon HK6900 driving a pair of Acoustic Research AR-11s.
Am I at all using these 90A or instantaneous current in transient peaks?
Here is what I found about the legendary Citation XX which has HCC of 200A. This is from the User guide pages for the less technical brains like mine.
Your thoughts on this?
I'm enjoying the discussion and I thought I'd pop a question.
I am curious if amplifiers with high current capabilities into difficult loads technically have a advantage over other discrete component amps in SQ. Or is this HCC Harman Kardon thing a marketing word only?
I have a Harman Kardon HK6900 driving a pair of Acoustic Research AR-11s.
Am I at all using these 90A or instantaneous current in transient peaks?
Here is what I found about the legendary Citation XX which has HCC of 200A. This is from the User guide pages for the less technical brains like mine.
Your thoughts on this?
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I agree, but finding a good amp is both objective and subjective. For example, I have heard several Levinsons and Krells - both are generally considered to be about the best there is. Yet, I find a consistence in both, which allows me to pick my choice. To me, Levinson tends to be a little on the colder side, but also a little more refined than Krell; Krell, on the other hand, while a touch less refined, has a certain immediacy and fire breathing that Levinson does not have, which I happen to value highly and thus prefer Krell.
Also, of all the tube amps I have heard, some were truly wonderful sounding, but even so, they never managed the sheer force and presence of quality transistor amps. It is possible that I simply haven't ran up to the ones which can manage it, of course, there are so many products around it's simply not possible to hear them all.
So, to me, even the exalted products and names, while sounding great, do not sound the same.
Evening Gents.
I'm enjoying the discussion and I thought I'd pop a question.
I am curious if amplifiers with high current capabilities into difficult loads technically have a advantage over other discrete component amps in SQ. Or is this HCC Harman Kardon thing a marketing word only?
I have a Harman Kardon HK6900 driving a pair of Acoustic Research AR-11s.
Am I at all using these 90A or instantaneous current in transient peaks?
Here is what I found about the legendary Citation XX which has HCC of 200A. This is from the User guide pages for the less technical brains like mine.
Your thoughts on this?
It's not very likely you will ever be using all of 90 Amps, because when you work it out, this would translate to 800 Watts into 2 Ohms. Long before that happens, your speakers are toast.
What that means is that essentially the amp is not sensitive to the speaker properties even if they are of the hard-to-drive type, as yours are. This means that the amps can deliver all of its nominal power (well, morst of it) even into difficult speakers.
Harman's HCC spec is only partially interesting simply because after all these years, I have never seen it defined in any way. What impedance, where in the spectrum, and most important, for how long, how long is the time interval. But the good news is that that most Harman's amps (except the entry level model or two) can indeed supply tremendous power peaks.
For example, my wife's HK 680, rated at 85/130W into 8/4 Ohms, using the standard IEC time interval of 20 mS, managed to pump out 540 Watts in peaks into 2 Ohms. I'd hate being a loudspeaker receiving that.
My venerable H/K 6550 integrated amp from 1993, with a SEPP output, managed some scary numvers in context of its nominal power.
And my Citation 24 power amp I haven't tried yet, but I'll bet it too can manage prodigious currents.
So, the answer to your question is partial - yes, you are using that current reserve, but nowhere near its aboslute maximum, under normal room conditions. It is used to keep the amp linear even when facing hard to drive loudspeakers, and many AR speakers were harder to drive than many others. As are my AR 94 speakers, used by my son - a second from the top Sansui AU-X701 integrated amp (nominally 100W/8 Ohms) struggles when pushed hard into them, but H/K's smaller 6550 has no problems.
You know, drive capability of an amp is a very important characteristic, but it is not the only one; I have heard H/K's bigger models, with all of their incredible drive capability, still sounding not too interesting. For example, their model 665, top integrated amp model from the mid 90ies, is a model I would not run out to own.
Strangely , my local jazz station goes from sounding very good to noisy and distorted (PR) not so on the one classical station left standing ....
They all will sound the same when playing loud , not so when soft, if one listens mostly loud then class-d is a good option ..
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