ATI AT2000 amps

[AcuDefTechGuy]

What about electronic noise floor? Was it higher than your other amps?

You mean like speaker hiss noise?

 

[GranteedEV]

You mean like speaker hiss noise?

yeah "speaker hiss noise"

 

[AcuDefTechGuy]

yeah "speaker hiss noise"

I didn't check. I could do that for you.

 

[DS-21]

I think the evidence is mounting that in ten years the only part of the high-end audio market that will probably exist is speakers.

Oh, the wire scam will still be around too. It's just too profitable for audio parts dealers, and audiophile customers are usually too stupid to know better.

So the Audio Critic thinks the pro amps they've reviewed/ measured sound just as good as all these "home" amps.

In fairness, Azcel was less than happy with the one Class D amp I recall him testing.

However, it's still worth noting that a Class D amp based on a decade-old chip from a now-bankrupt firm (Tripath) that the chipmaker optimized for car-fi use, that the amp maker installed in an obviously poorly-engineered product (see the review) still produced a frequency response only up 0.4dB at 20kHz, and down 0.4dB at 20Hz. Take that measured performance, and put competently-designed protection circuitry around it, and I think everyone would be hard-pressed to distinguish it from any Class A/AB/AB+B/G/H amp in a controlled comparison.

Although I did not hear any noise with the Crown XLS amps.

I'm curious about these, even though I don't personally need amps and definitely won't be buying one unless something breaks. But I think they warrant another thread.

 

[AcuDefTechGuy]

In fairness, Azcel was less than happy with the one Class D amp I recall him testing.

Okay, I better retract my statement and say "Harman Crown Amps or other more expensive amps".

 

[AcuDefTechGuy]

What about electronic noise floor? Was it higher than your other amps?

My ATI amps were the 1st amps I've owned with absolutely no hiss even with the ear against the tweeter.

Looks like the Crown amps have some slight hiss sound, but only with the ear pressed against the tweeter. It was silent from 6 inches out.

 

[cpp]

Ds-21

Oh, the wire scam will still be around too.

got that right. That one will never die..

 

[blair6878]

AT2000 series (balanced) vs AT1802

Hi cpp, it's great that your 1800 is silent! I was reading through this thread and noticed your signature shows that you have an AT2000 and AT1802. Could you please tell me if you were able to detect any difference between the two. I didn't have balanced outputs, but was told by an ATI tech that the 2000 series had a faster slew rate (contrary to the specs, even through RCA), which I would be interested in if it was actually noticeable. I was interested in improving the slew/damping over my stock Denon 3808. I currently have a POA-2800 which I can detect an audible speed increase with....but wanted to move to something in 5-channel (at2005 / at1805 / outlaw 7500) without loosing the speed or noise floor of my POA. Thanks for any info.

Quote:
Does the AT1800 have any hiss anyone?

dead quiet dead quiet

 

[fuzz092888]

I can't speaker about the ATI directly, but I have an outlaw 755 and it's dead silent so I'd imagine the newer outlaw 7500 would be just as silent and since ATI is the OEM for outlaw both of those amps should be dead silent.

 

[blair6878]

Thanks Alex, I guess the earlier Outlaw amps are of similar design, but I was really trying to split hairs between the AT2000 series and the AT1800 series. From what I understand, there is a big difference between the design, with the common mode rejection of the fully balanced AT2000 (also Outlaw 7500) vs the non-balanced 1805 (which can be had for much less $$$). I probably wouldn't be able to tell the difference anyhow, but hoping it at least is not a step backwards for me from my POA.

 

[fuzz092888]

The POA 2800 is a beast and if it were me I'd probably go with the 2005 to keep things as comparable as possible.

I'll just throw this out there, but AB International also makes HT amps. They're 50% off of the retail price for now, which for a 200WPC 5 channel amp comes to $2250+shipping. For the 50% off price there is only a 1 year warranty. Full retail comes with a 5 year warranty. Additional years of warranty can be purchased for $250 per year

These are the specs for the 6 channel 400WPC version (the only specs I could find)

• Six channel amplifier
• 400w per channel @ 8 ohms
• 600w per channel @ 4 ohms
• 750w per channel @ 2 ohms
• 1200w per channel bridged @ 8 ohms
• 1500w per channel bridged @ 4 ohms
• All channels driven
• Three independent power supplies
• Balanced XLR & gold RCA inputs
• Bridge switches
• Star Point Grounding w/Ground lift switch
• Dual temperature activated fan
• Selectable input sensitivity
• "Soft Clip" circuitry
• 4.5-rack space
• 12V trigger
• Removable IEC power cord
• Optional power supply cap upgrade

Additional Features:
• Frequency Response: +/- 0.25dB 20Hz - 20kHz
• Distortion: No more than 0.05%THD or IM, 0.01W to rated output, 20Hz-20kHz (Typically 0.01%)
• Hum & Noise: 120dB below rated output (unweighted, 20kHz bandwidth)
• Input Sensitivity: 2.0VRMS for rated output (selectable)
• Input Impeadance, 15K balanced, 30K un-balanced
• Input Connectors: Gold RCA inputs, XLR (Balanced)
• Output Connectors: Gold Binding posts
• Controls & Indicators
(Front Panel) Ac mains power switch (breaker), power on LED,
(Rear Panel) ground lift switch, stereo/bridge switches per each two channels
• Damping Factor: 1100:1 @ 20Hz, 1000:1 @ 1kHz
• Dynamic Headroom 3.5db
• Slew Rate: Closed-loop response greater than 40V/us
• Crosstalk: -80dB
• Mainframe Power Supply: Toroidal transformer, 3 separate power supplies w/ 6ea 15k/uf capacitors
• Turn-On Delay: 3 seconds
• Power Requirements:
AC Mains 100-240VAC50/60Hz ( factory wired ) 20A/30A 100-120VAC, 15/20A 220-240VAC recommended
• Thermal Protection: Each channels thermal sensor activates channel shutdown if an over-heating condition exists.
• DC Protection: DC sensor activates channel shutdown if DC condition exists.
• Heatsink and Cooling:
3 State fan, off-low-high two speed cooling fan utilizing heatsink extrusions,
Quiescent amplifier ON condition has no fan. Fans do not engage until heavy usage conditions.
• Construction: 14-gauge cold-rolled steel with 3/16" heavy aluminum front panel.
• Dimensions: 8.5” height with rubber feet, 17.25” width, 17” depth overall
• Rack mount ears available for purchase separately for standard 19”
• Shipping Weight 76lbs

 

[AcuDefTechGuy]

I currently have a POA-2800 which I can detect an audible speed increase with....but wanted to move to something in 5-channel (at2005 / at1805 / outlaw 7500) without loosing the speed or noise floor of my POA. Thanks for any info.

What audio speed are you talking about?

You mean the music sounds faster literally ?

 

[blair6878]

Yes AcuDefTechGuy, I did an a/b comparison and could hear a slight but distinct difference - and I was not the only one that could hear this Of course the music has the same tempo....but the response/transitions were notably quicker (audiophiles, please help me with the correct adjectives). I would imagine this is due to the slew rate and/or damping factor of the larger amp. So....trying to get the same improvement in a 5-channel....and cpp's comments on this thread about the low noise floor of the affordable AT1800 series (similar to your AT2004) peaked my interest.

BTW, I see you have the at6012. I was curious if you currently had that hooked up and how you were using it?

You mean the music sounds faster literally ?

 

[cpp]

Hi cpp, it's great that your 1800 is silent! I was reading through this thread and noticed your signature shows that you have an AT2000 and AT1802. Could you please tell me if you were able to detect any difference between the two. I didn't have balanced outputs, but was told by an ATI tech that the 2000 series had a faster slew rate (contrary to the specs, even through RCA), which I would be interested in if it was actually noticeable. I was interested in improving the slew/damping over my stock Denon 3808. I currently have a POA-2800 which I can detect an audible speed increase with....but wanted to move to something in 5-channel (at2005 / at1805 / outlaw 7500) without loosing the speed or noise floor of my POA. Thanks for any info.

Sorry been on vacation.. I hooked up both amps to my Usher speakers and they are quiet and when listening to music they sound the same, if there is a difference I sure can't hear it regardless of the specs. I purchased my amps from ATI.

 

[AcuDefTechGuy]

BTW, I see you have the at6012. I was curious if you currently had that hooked up and how you were using it?

My Linkwitz Orion speakers require 8 channels of amps - four channels per speaker (quad-amp). So I'm using 8 of the 12ch on the AT6012.

ATI makes awesome SS amps. They make some amps for Mark Levinson, Lexicon, JBL (the Harman company), Cary, Outlaw, Theta, B&K (ATI owns Theta & B&K), Earthquake.

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

 

[cpp]

My Linkwitz Orion speakers require 8 channels of amps - four channels per speaker (quad-amp). So I'm using 8 of the 12ch on the AT6012.

ATI makes awesome SS amps. They make some amps for Mark Levinson, Lexicon, JBL (the Harman company), Cary, Outlaw, Theta, B&K (ATI owns Theta & B&K), Earthquake.

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

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

 

[blair6878]

Thanks cpp, I thought that might be the case. Since I do not use balanced cables, I can save some $$ getting the at1805.

they sound the same, if there is a difference I sure can't hear it regardless of the specs.

 

[blair6878]

I see, so you are not using it as a distribution system...which requires some additional equipment...but you still need to provide 8 separate preamp channels I guess.

My Linkwitz Orion speakers require 8 channels of amps - four channels per speaker (quad-amp). So I'm using 8 of the 12ch on the AT6012.:

It might be more noticeable since my speakers are very efficient (Klipsch Forte II when tested). Me and my other-half went through many A/B listening sessions and she would be able to pick out the faster amp without knowing which I was switching to, almost every time. They were not perfectly level matched, so maybe that had something to do with it too. I was not familiar with your speakers, are they harder to drive? They certainly look quite impressive !!

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

 

[templemaners]

They were not perfectly level matched, so maybe that had something to do with it too.

That likely had everything to do with it.

 

[Rickster71]

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