ATI AT2000 amps

[AcuDefTechGuy]

Wow so you got the big beast. My 2000 is the 2003 but you got those Orions that needs that beastly power

Well, the AT6012 is the "default" recommended amp for the Orion. Linkwitz said anymore than that and you use at your own risk of blowing the drivers.

But that was one cool thing about the Orion. They are actively quad-amped (not passively), which you can't say about many speakers.

The 6012 is rated at 60wpc x 12. But the Audio Critic measured 80wpc into 8 ohms. The Orion are 8 ohm. So each speaker can potentially get 80 x 4 = 320 watts, which isn't that much compared to the AT3002 or other amps. However, I doubt the Orion consume anywhere close to that. One advantage of active design is much better efficiency in power handling, whereas passive design can have more "wasted" power.

 

[blair6878]

Thanks Rickster71, as per your link, both Slew Rate & Damping Factor are defined in terms of how "quickly" the amp can perform it's tasks. Here is another link I came across that goes into greater detail and in the 3rd section from the bottom, states "You can hear a 10% difference in speaker control. Trust me!"
Legendary Audio Classics: Damping Factor

Here's a little on Slew Rate & Damping Factor:
What is Slew Rate and Damping Factor? — Reviews and News from Audioholics

AcuDefTechGuy, see above.

But I don't know about "audio speed" since I've never experience this phenomenon.

templemaners, I tested the two configurations (avr3805 by itself & addition of POA 2800) using my Forte IIs a while ago so I couldn't say with 100% certainty, but I remember that I knew level matching was a factor, so while testing I varied the volume both ways relative to each other...so did my best with what equipment I had to perform the A/B comparison.

That likely had everything to do with it.

There are some that believe you can hear the difference, at some point, when the amp does not have an adequate Damping Factor and is connected to correspondingly difficult to drive speakers. From what little I understand, even though my Klipsch horns are very efficient, the input impedance varies wildly and actually dips (as per measurements I've seen for similar Klipsch models) below 4 ohms at lower frequencies, just were the Damping Factor is needed most to counteract the inertia of the large 12" drivers from continuing to move in the wrong direction (and I believe the 15" passive radiators would greatly compound this effect). This is just the thing that the improved Damping Factor of an external amp might be able to help, in an audible amount (*if it was initially an issue*). So I'll choose to believe that I did hear a difference....at the same time I certainly would not totally discount other peoples observations and appreciate them sharing their experiences. However, I think it might also be save to say that nobody here made those observations on the same system components that I used.

BTW, I originally said it was the AVR3808, but I now remember that it was actually the AVR3805 that I had back then, which I believe has an even higher output impedance (lower Damping Factor).

Anyhow, I think I am leaning towards the ATI AT2005 / Outlaw 2005. I like how they eliminate crosstalk through their common mode rejection. What was strange is that the AT1805 is not a dual differential design, but still ATI lists the same fantastic crosstalk specs. Maybe their specs are a bit too generalized [wrong] among their different models?

 

[fuzz092888]

There are some that believe you can hear the difference, at some point, when the amp does not have an adequate Damping Factor and is connected to correspondingly difficult to drive speakers. From what little I understand, even though my Klipsch horns are very efficient, the input impedance varies wildly and actually dips (as per measurements I've seen for similar Klipsch models) below 4 ohms at lower frequencies, just were the Damping Factor is needed most to counteract the inertia of the large 12" drivers from continuing to move in the wrong direction (and I believe the 15" passive radiators would greatly compound this effect). This is just the thing that the improved Damping Factor of an external amp might be able to help, in an audible amount (*if it was initially an issue*). So I'll choose to believe that I did hear a difference....at the same time I certainly would not totally discount other peoples observations and appreciate them sharing their experiences. However, I think it might also be save to say that nobody here made those observations on the same system components that I used.

BTW, I originally said it was the AVR3808, but I now remember that it was actually the AVR3805 that I had back then, which I believe has an even higher output impedance (lower Damping Factor).

Anyhow, I think I am leaning towards the ATI AT2005 / Outlaw 2005. I like how they eliminate crosstalk through their common mode rejection. What was strange is that the AT1805 is not a dual differential design, but still ATI lists the same fantastic crosstalk specs. Maybe their specs are a bit too generalized [wrong] among their different models?

I think you're way too caught up on damping factor. You're missing a key factor here that sorta makes all that you're saying about damping factor more irrelevant than you currently believe.

Riddle me this, do you connect a speaker directly to an amplifier?

As a hint, I'll reiterate DIRECTLY

I'll also say that if you believe you heard something then you did. Whether or not the difference was real or imagined is something else entirely.

 

[blair6878]

So...you believe that I believe. Fair enough.
...and no, I do not connect my amp directly to the driver....there is always the crossover circuitry in between, if that's what you mean.

Certainly the damping factor does not matter to me, obtaining the best sound/performance does. Damping factor appears to potentially describe the difference I heard and appreciated. The 3808 certainly can't compete with the sheer power/headroom of these external amps, especially with 5 channels driven. One of the things I do is record thunderstorms. During playback, you need a low noise floor so that [by design] you can turn the volume way up just to hear the rain....then when the thunder comes your amp is cranked up and ready. The better the power reserve the quicker (oops, there I go talking about speed again) the amp can respond to the signal. BTW, thanks for everyone attempting to enlighten me. The internet is flooded with conflicting views and without extensive equipment and experience, it certainly is challenging to "know" with 100% certainty. I certainly could not hold a candle to some of the talent that happens by this forum....just a small hobby for me.

Riddle me this, do you connect a speaker directly to an amplifier?

I'll also say that if you believe you heard something then you did. Whether or not the difference was real or imagined is something else entirely.

 

[AcuDefTechGuy]

The only thing that matters is the end result, which is people cannot statistically tell the difference between amps in double-blinded tests.

 

[Irvrobinson]

The only thing that matters is the end result, which is people cannot statistically tell the difference between amps in double-blinded tests.

More accurately, people cannot statistically tell the difference between the amps that were tested with the speakers that were tested, in the tests that have been conducted.

 

[blair6878]

Hi AcuDefTechGuy, Agreed. Only the end result matters. Tell me this though, given a higher playback level, wouldn't you think that a system would benefit from an external amp for increased power reserves, if nothing else? I would think that the AVR3808 would not be performing it's best as you crank it higher, regardless of which spec begins to suffer, be it THD, headroom, .....or damping factor/slew rate. Realize that my true goal is just to somehow rationalize the purchase of an ATI amp like yours

The only thing that matters is the end result, which is people cannot statistically tell the difference between amps in double-blinded tests.

 

[blair6878]

Good point, and another factor would be "who" was doing the listening. Unfortunately, the thing that goes along with experience is "age"....and most all loose some of their finer hearing abilities at a pretty early age.

More accurately, people cannot statistically tell the difference between the amps that were tested with the speakers that were tested, in the tests that have been conducted.

 

[AcuDefTechGuy]

Realize that my true goal is just to somehow rationalize the purchase of an ATI amp like yours

Oh, sorry, why didn't you say so?

Yes, you must purchase an ATI amp and be cool like us.

Why, I have four ATI amps no less.

I think for critical listening at higher volume, in bigger rooms, and more demanding speakers, yes, higher quality more powerful amps like ATI will be a good thing.

As Irv hinted, I shouldn't make blanketed statements like "all amps sound the same". I wasn't thinking. Pardon me.

 

[ahblaza]

Oh, sorry, why didn't you say so?

Yes, you must purchase an ATI amp and be cool like us.

Why, I have four ATI amps no less.

I think for critical listening at higher volume, in bigger rooms, and more demanding speakers, yes, higher quality more powerful amps like ATI will be a good thing.

As Irv hinted, I shouldn't make blanketed statements like "all amps sound the same". I wasn't thinking. Pardon me.

WOW..."Pardon me" and "I wasn't thinking" in the same sentence You're such a maniac, strangely I concur with your madness: you bring order to chaos

 

[fuzz092888]

So...you believe that I believe. Fair enough.
...and no, I do not connect my amp directly to the driver....there is always the crossover circuitry in between, if that's what you mean.

Certainly the damping factor does not matter to me, obtaining the best sound/performance does. Damping factor appears to potentially describe the difference I heard and appreciated. The 3808 certainly can't compete with the sheer power/headroom of these external amps, especially with 5 channels driven. One of the things I do is record thunderstorms. During playback, you need a low noise floor so that [by design] you can turn the volume way up just to hear the rain....then when the thunder comes your amp is cranked up and ready. The better the power reserve the quicker (oops, there I go talking about speed again) the amp can respond to the signal. BTW, thanks for everyone attempting to enlighten me. The internet is flooded with conflicting views and without extensive equipment and experience, it certainly is challenging to "know" with 100% certainty. I certainly could not hold a candle to some of the talent that happens by this forum....just a small hobby for me.

The crossover and the actual speaker wire running from the amp the the speaker.

SNR would be a better indicator of noise floor I think.

Try reading this about damping factor

http://www.roger-russell.com/wire/damptoole.htm

You may also want to read this, I think it's a great general article about hearing and psychology and how subjective the whole thing can be.

NwAvGuy: What We Hear

Believe me I'm not trying to talk you out of an ATI amp. Quite the opposite, I'm all for big beefy power amps Right now I've got an outlaw 755 and a Cinepro 1K2

 

[Irvrobinson]

WOW..."Pardon me" and "I wasn't thinking" in the same sentence You're such a maniac, strangely I concur with your madness: you bring order to chaos

It's a thing just between us Salon 2 owners using ATI 3000-series amps and monster subs.

 

[blair6878]

Thanks for the links, I am interested in that sort of stuff. It will take me some time to study this info. It reminds me of a NatGeo series I saw called "Brain Games". It's very humbling watching these videos realizing how flawed & easily distracted our observations can be:
Videos for Brain Games: Pay Attention! | National Geographic Society

There are still a few gotchas about my observation being discussed:

1) Your article on DF basically said it's a meaningless spec...BUT, it does state that "a DF of 20 or more will ensure that everything possible has been done"....implying that a DF below 20 might be an issue, and I wouldn't doubt the possibility that the DF of the 3805 might drop below this point at some frequencies/conditions...just saying. lol.

2) My other half that confirmed my findings was quizzed as to what she heard and which she liked better as I switched back and forth. There was no visual way for her to detect which configurations she was listening to....and she does not really even know what an external amp is...of course she knew what I was thinking and we might also come back to the level matching issue again...don't remember where it was set when she joined the testing.

Talking about the psychology of hearing, when we play back a good thunderstorm recording, we actually began to feel colder...so we're certainly human.

Coincidentally, there is a new listing on ebay for an AT2005 for a good price of $1400+shipping, but I spoke to the guy and it's like 8 years old. For a few hundred more, I would prefer to wait for a sale on b-stock, with warranty.

Part of me is still considering a Sunfire TGA 7401 as well. From what I read, it has two sets of outputs, one produces a solid-state type sound and the other more tube-like sound....(oh, but that is assuming that an amp can actually produce a sound that is audibly different somehow). Anyhow, it's lighter, twice the output power, but the THD measurement are relatively poor but I would think good enough. It has some type of switching power supply that makes it a type of D-class amp. The crosstalk is not going to be as good as the ATI either...and this I believe you can hear [under test conditions] and might take from the stereo separation [an undetectable amount]. Decisions, decisions.

The crossover and the actual speaker wire running from the amp the the speaker.

SNR would be a better indicator of noise floor I think.

Try reading this about damping factor

http://www.roger-russell.com/wire/damptoole.htm

You may also want to read this, I think it's a great general article about hearing and psychology and how subjective the whole thing can be.

NwAvGuy: What We Hear

Believe me I'm not trying to talk you out of an ATI amp. Quite the opposite, I'm all for big beefy power amps Right now I've got an outlaw 755 and a Cinepro 1K2

 

[fuzz092888]

1) Your article on DF basically said it's a meaningless spec...BUT, it does state that "a DF of 20 or more will ensure that everything possible has been done"....implying that a DF below 20 might be an issue, and I wouldn't doubt the possibility that the DF of the 3805 might drop below this point at some frequencies/conditions...just saying. lol.

Well I never did say an AVR could keep up with an external amp and if you had asked I would have said that for the loud stuff an external amp is a must. The whole DF thing was more for between an external amp and another external amp not between an external and an AVR. I figured the differences between the latter would be kinda obvious

 

[PENG]

Well I never did say an AVR could keep up with an external amp and if you had asked I would have said that for the loud stuff an external amp is a must. The whole DF thing was more for between an external amp and another external amp not between an external and an AVR. I figured the differences between the latter would be kinda obvious

All depends on the application. For what I need, listening at no more than 105 dB peaks, my old 3805 has no trouble keeping up with my other amps in both voltage and current. I am now using it to drive a pair of 86 dB sensitivity speakers with low impedance dips. None of us in the room can ever hear any noticeable difference in speed or anything with any anything with or without external amps. I like amps, so I have amps but I am not going to say they make a whole lot of difference in sound quality when they really don't. I highly doubt the 3805 would have its DF dip below 20 under any real world conditions. Amps certainly help when you need the power, that's about it.

 

[blair6878]

Gotcha...and agreed, I don't think any decent external amp would have a damping factor below 20, so according to the article you linked to, damping factor comparisons for competing external amps would be irrelevant.
Thanks again.

Well I never did say an AVR could keep up with an external amp and if you had asked I would have said that for the loud stuff an external amp is a must. The whole DF thing was more for between an external amp and another external amp not between an external and an AVR. I figured the differences between the latter would be kinda obvious

 

[PENG]

The DF of the 4306 looks good enough to me. The 3805 should be similar, and it sounds as good and powerful as my 4308 too.

AVR-4306 Measurements and Analysis — Reviews and News from Audioholics

 

[fuzz092888]

All depends on the application. For what I need, listening at no more than 105 dB peaks, my old 3805 has no trouble keeping up with my other amps in both voltage and current. I am now using it to drive a pair of 86 dB sensitivity speakers with low impedance dips. None of us in the room can ever hear any noticeable difference in speed or anything with any anything with or without external amps. I like amps, so I have amps but I am not going to say they make a whole lot of difference in sound quality when they really don't. I highly doubt the 3805 would have its DF dip below 20 under any real world conditions. Amps certainly help when you need the power, that's about it.

Agreed, I don't think from a SQ perspective the external amps I use sound different or much different if there is any from the amp section on the onkyo 3009 I have, which has a pretty decent amp section.

I do however tend to like my movies at reference levels so that's where I think I might hear a difference. I have no way of doing a true ABX comparison, but I figure it's probably better to externally amp rather than push the amp section on the receiver. I know between the Cinepro and the outlaw, they barely flinch when pushed.

 

[blair6878]

Hi Peng, the info I was looking at was output impedance graphs (which is inversely proportional to the DF) for the 3805, 3806, 3808....and all these are weaker than the larger 4306 by a factor of 10. BTW, my observation I was discussing was just slight. Hence the uncertainty. We would also need corresponding impedance graphs for our speakers to really draw any [theoretical] conclusions. Ironically, the link I was just given discusses the importance of system coordinated impedance as well, but for a headphone application. I had used the 3805 for years too. If it wasn't for that darn HDMI connection, I would still be using it.

The DF of the 4306 looks good enough to me. The 3805 should be similar, and it sounds as good and powerful as my 4308 too.

AVR-4306 Measurements and Analysis — Reviews and News from Audioholics

 

[PENG]

Hi Peng, the info I was looking at was output impedance graphs (which is inversely proportional to the DF) for the 3805, 3806, 3808....and all these are weaker than the larger 4306 by a factor of 10. BTW, my observation I was discussing was just slight. Hence the uncertainty. We would also need corresponding impedance graphs for our speakers to really draw any [theoretical] conclusions. Ironically, the link I was just given discusses the importance of system coordinated impedance as well, but for a headphone application. I had used the 3805 for years too. If it wasn't for that darn HDMI connection, I would still be using it.

I hear what you are saying. I went from 3805+/11amp to 4308+/-amps to AV7005+amp(s) and like fuzz said, without doing a proper AB, I, and none at home can tell any improvements in SQ but then we typically have the volume at around -20 to -28. On rare occasions I would crank it up to -10 to -15. So 99% of the time, the amps basically just sit there wait for those intermittent 15 to 20 dB peaks and then stretch just a little. Fuzz seems to enjoy reference level so during some peaks typically found in movies I can see why in his application a Cinepro or big Outlaw would be put to use, and as they say YMMV too..

Back to the DF thing, if you read one of the links provided by fuzz you will see that it is only inversely proportional to the output impedance of an amp if the other signal path including the speaker's impedances are ignored. So in real world it is hard to prove with facts that even a DF of 20 to 30 would sound noticeably different than say 300 and above. I prefer to stay well clear of 50 but that's just for peace of mind, same reason why I have more than one amps in my system. You really don't need the speaker's impedance graph to draw conclusions if you are comparing DF >30 unless your speaker has dips below 2 ohms, just go over the math yourself (fuzz;s link) you would likely agree with me/us.

Lastly, don't assume the 3800 series Denon are that different from the 4000 series. I have read pretty much every available googleable free lab measurements for the 3808, 4310, 4311, 4308, 4810 and found no evidence whatsoever that their amp sections are all that different. In fact HTM did both 3808 and 4308 and the 3808 yielded better measurements in the power output department even though it was rated slighly lower. Base on those numbers I believe it is likely (just an educated guess) they use the same amp section for the sake of standardization and cost effectiveness.

HTM measurements on the 3805:

'Into 4 ohms, the amplifier reaches 0.1% distortion at 218.4 watts and 1% distortion at 243.0 watts.'

That's quite similar to that for the 430X's.

Now if you are talking about Dennon's lower models such as the 2000 series then all bets are off and you may get to see lower DF dips down to the 20 (again it may still be not noticable) range for 4 ohm rated speakers. Even then I am just taking a wild guess and I doubt too many people would use the 2000 and below series for 4 ohm speakers except for those minute HTIAB types.

Edit: let me add one more link:
http://www.trueaudio.com/post_013.htm
Seems extreme but I guess he wanted to make a point..