Why didn't they choose an AVR?

[TechHDS]

I'm sure PENG could give us more detailed answers on the technical side.

To me, a good amp has plenty of power to handle all loads, even 1 ohm loads.

For example, McIntosh amps are very good amps. But they will output the same power into 8 ohms as 4 ohms and 2 ohms (like 300 Watts into 8/4/2 ohms).

If your speakers are 8 ohms and have a sensitivity of 88dB/w/m and you sit 3 meters away and wanted 100dB, your amp would need to output 143 Watts to produce 100dB.

But if you had this $3K Benchmark amp, it would clip at 108 Watts into 8 ohms.

What good is the "double-down" spec when it clips at 108 watts?

So it depends on the case.

Thanks ADTG, I always wondered why McIntosh amps power output are the same no matter the load. Aways knew all amps are not created equally, and why they all dont' sound the same. Clipping is Not a good thing especially with an add on amp. So yeah specs can look good on paper but when used in real World loads and "value" priced, amp will show it's true colors at reference volume levels. I mean after all why add a add on amp if at reference volume levels all you will get is dirty nasty noise? So your point on a good solid AVR is a logical choice. For most applications.

 

[AcuDefTechGuy]

Thanks ADTG, I always wondered why McIntosh amps power output are the same no matter the load. Aways knew all amps are not created equally, and why they all dont' sound the same. Clipping is Not a good thing especially with an add on amp. So yeah specs can look good on paper but when used in real World loads and "value" priced, amp will show it's true colors at reference volume levels. I mean after all why add a add on amp if at reference volume levels all you will get is dirty nasty noise? So your point on a good solid AVR is a logical choice. For most applications.

The problem with some people is that they focus everything on the wrong thing - inaudible specs, instead of looking at the big picture.

As mentioned many times by many members here already, people cannot tell the difference between all these SNR and THD specs. It's all academic and nice to look at, but not to lose sleep over.

Aside from some cheap amps that I wouldn't touch , there are many good amps out there - both separates and AVR. And both have their uses.

This $3K Benchmark Amp has better SNR than most amps out there, including Mark Levinson, Krell, Bryston, Anthem, etc. But who cares if you can't tell the difference between these SNR?

And who gives a rat's butt how good the inaudible SNR is when the amp clips at 108 Watts ?

Now going back to this silly thread question, if I opened up a speaker business and wanted great publicity to sell my $20K speakers, would I choose an AVR to test my $20K speakers, do I choose a $20K amp to test my speakers ? Geez I wonder.

 

[PENG]

I'm sure PENG could give us more detailed answers on the technical side.

To me, a good amp has plenty of power to handle all loads, even 1 ohm loads.

For example, McIntosh amps are very good amps. But they will output the same power into 8 ohms as 4 ohms and 2 ohms (like 300 Watts into 8/4/2 ohms). They don't have to "double-down".

If your speakers are 8 ohms and have a sensitivity of 88dB/w/m and you sit 3 meters away and wanted 100dB, your amp would need to output 143 Watts to produce 100dB.

But if you had this $3K Benchmark amp, it would clip at 108 Watts into 8 ohms.

What good is the "double-down" spec when it clips at 108 watts?

So it depends on the case.

But I am at work and now on lunch break, will be back in a few hours.

 

[AcuDefTechGuy]

But I am at work and now on lunch break, will be back in a few hours.

You don't eat in the office every single day like me?

 

[KEW]

You don't eat in the office every single day like me?

I thought that was old dried up mayonnaise on my pills!

 

[AcuDefTechGuy]

I thought that was old dried up mayonnaise on my pills!

Hey, well, you want those pills or don't you ?

Kind of hard to eat out when they're calling my phone whenever they (all those nurses and physicians) need something.

Can't just close the office like in retail pharmacy.

 

[TechHDS]

The problem with some people is that they focus everything on the wrong thing - inaudible specs, instead of looking at the big picture.

As mentioned many times by many members here already, people cannot tell the difference between all these SNR and THD specs. It's all academic and nice to look at, but not to lose sleep over.

Aside from some cheap amps that I wouldn't touch , there are many good amps out there - both separates and AVR. And both have their uses.

This $3K Benchmark Amp has better SNR than most amps out there, including Mark Levinson, Krell, Bryston, Anthem, etc. But who cares if you can't tell the difference between these SNR?

And who gives a rat's butt how good the inaudible SNR is when the amp clips at 108 Watts ?

Now going back to this silly thread question, if I opened up a speaker business and wanted great publicity to sell my $20K speakers, would I choose an AVR to test my $20K speakers, do I choose a $20K amp to test my speakers ? Geez I wonder.

ADTG, cheap amps come in all shape and sizes.. Sometimes when all you have is bologna for your sandwiches, you go with bologna, But when you can afford ribeye steak you go with a slab of Pass Lab. One day I may jump on a nice juicy Krell,Pass lab or McIntosh amp till than my bologna Amp good enough .

 

[AcuDefTechGuy]

ADTG, cheap amps come in all shape and sizes.. Sometimes when all you have is bologna for your sandwiches, you go with bologna, But when you can afford ribeye steak you go with a slab of Pass Lab. One day I may jump on a nice juicy Krell,Pass lab or McIntosh amp till than my bologna Amp good enough .

Well, there are a lot more important things in life than amplifiers.

I don't know about bologna. I like honey ham. I think they cost about the same.

 

[KEW]

@ADTG, I believe I read somewhere that one of the tell tail signs of a good amp build, is that it should be able to output two times the power output from 8 ohms into 4ohms. If I worded that right, say a amp outputs 200 X 2 at an 8 ohm load, a good amp build should output double that into a 4 ohm load. Would that be correct? also say a amp that can't output two times the output into a 4 ohm load, Now my question, would it be because of #1, smaller power supply, #2 power trans at the rail? and #3, smaller Caps ufs?. just trying to gain some knowledge on amp build.

That is a popular notion and theoretically, a "perfect" amp would do that. I am not sure how many really do though.
But you can make a bad decision based on this approach.
I wish I had a better memory for details (I am going to make up numbers for my example).
An amp manufacturer specifies as 75WPC X 2 into 8 Ohms and 150WPC into 4 Ohms, both RMS at 0.07 THD so you'd assume this is a "world class" implementation, however when this unit was bench tested independently it gave 115WPC into 8 Ohms and 152WPC into 4 Ohms! So the marketing department deliberately under-rated the 8 Ohm rating to meet the vaulted "double down" criterion.
In truth, this unit only produces 32% more power into 4 Ohms (instead of 100% more). It seems like 50-60% is the norm for mainstream AVR units that are reporting power based on their actual test numbers.

Most recently, I have seen more and more manufacturers providing 8 Ohm values as RMS watts from 20-20khz and 0.05% THD, then reporting 4 Ohm values at 1kHz at 1.0% THD to inflate their numbers in order to get closer to the "double down" criterion.

 

[TechHDS]

That is a popular notion and theoretically, a "perfect" amp would do that. I am not sure how many really do though.
But you can make a bad decision based on this approach.
I wish I had a better memory for details (I am going to make up numbers for my example).
An amp manufacturer specifies as 75WPC X 2 into 8 Ohms and 150WPC into 4 Ohms, both RMS at 0.07 THD so you'd assume this is a "world class" implementation, however when this unit was bench tested independently it gave 115WPC into 8 Ohms and 152WPC into 4 Ohms! So the marketing department deliberately under-rated the 8 Ohm rating to meet the vaulted "double down" criterion.
In truth, this unit only produces 32% more power into 4 Ohms (instead of 100% more). It seems like 50-60% is the norm for mainstream AVR units that are reporting power based on their actual test numbers.

Most recently, I have seen more and more manufacturers providing 8 Ohm values as RMS watts from 20-20khz and 0.05% THD, then reporting 4 Ohm values at 1kHz at 1.0% THD to inflate their numbers in order to get closer to the "double down" criterion.

Kew, I can't thank you enough what you just posted. It's seems that most are doing just that, just went look at the specs on that XPA-5 yep sure enough it is rated at 4 Ohm 1kHz. at 1.0% THD. Reference level my ass!. . lol
My bad it's rated 300 at 4 Ohm at 0.1kHz
and 200 @ 8 Ohm @ 0.1kHz but still, ain't nowhere near world class! just a lil more pop for ya coin..

 

[KEW]

Kew, I can't thank you enough what you just posted. It's seems that most are doing just that, just went look at the specs on that XPA-5 yep sure enough it is rated at 4 Ohm 1kHz. at 1.0% THD. Reference level my ass!. . lol
My bad it's rated 300 at 4 Ohm at 0.1kHz
and 200 @ 8 Ohm @ 0.1kHz but still, ain't nowhere near world class! just a lil more pop for ya coin..

Well, don't get too wrapped up in the "double down" mentality. It is a good standard, but can also cost you needlessly!

It is a shame to see how the new owners of Emotiva are running things. They still offer decent products at decent prices, but they used to be a class act at great prices. IOW, I believe they are largely still competitive, but they used to be a no-brainer.

If you are looking for power similar to the XPA-5, also consider Outlaw Model 2200. You can buy 5 for $1479 (see the green "multiple units" link under the "add to cart" button) and they are 200/300W RMS full band at 0.05%THD
http://www.outlawaudio.com/products/2200.html?gclid=Cj0KCQiAzMDTBRDDARIsABX4AWzXb9Mse6o_T5G0S--zYPHXBCUXMVLhfJXaDS8ptFqNCxtbJ-UShosaAgC6EALw_wcB

If 300W at 4 Ohms and 200W at 8 ohm is enough, you are wasting money chasing after a "double down" amp!

The ATI built Monoprice Monolith-5 is also a bargain, but some people have had issues with transformer hum (myself included), so I am a little reluctant to suggest them unless you have a closet or someplace for the amp.

 

[RichB]

My brother-on-law had a pair of Model 2200's and they got a bit harsh driving the Revel F206's into the mid 80 DB range. Perhaps that was the point when the class-G swiches to the other rails.

The Outlaw Model 5000 or Monoprice Monolith are good choices in a classic A/B design.

- Rich

 

[Mikado463]

ADTG, cheap amps come in all shape and sizes.. Sometimes when all you have is bologna for your sandwiches, you go with bologna, But when you can afford ribeye steak you go with a slab of Pass Lab. One day I may jump on a nice juicy Krell,Pass lab or McIntosh amp till than my bologna Amp good enough .

I happen to like bologna (German) as well as my Pass amps !

 

[TechHDS]

I happen to like bologna (German) as well as my Pass amps !

@Mikeado, Now your after my heart! What class Pass do you have? and I would Love a slice of that famous (German) Bologna! Man!
All I can get is f..kin American made, about the best I can get here is Oscar Mayer and that ain't saying much. I have to put jalapeno slices a slice of tomato and american cheese just to make a good sandwich.

 

[PENG]

Well shoot, I can handle it if you guys can.

I can go there and say everyone needs at least 300W into 8 ohms.

Now if the AHB2 is bridged, you get 380W into 8 ohms for $6K for 2 Ch. What is the SNR and other inaudible specs when it is in bridged mode (not that it matters since it's inaudible) ?

480 W into 6 ohms if you bridge it. SNR should drop just 3 dB when bridged, still inaudible as you said.

 

[PENG]

If it's any consolation the relsale value is higher in CA.
The UDP-205 is a very nice player. I didn't think I would like it but UHD is very nice on an OLED.

I skimmed the original Benchmark thread and there are a lot of interesting posts before it went dark.

I wish the cripes, that Emotiva would release their new HDMI 2.0a board. I purchased a 18Gig HDMI 2.0 switch that I will use when the XMC-1 gets shipped out for an upgrade. Processors are nice but I alway enjoy my system when the Oppo's are connected directly to my amps. I keep trying REQ, perhaps one day it will float my boat

I am eyeing a used AHB2 in silver but I would ship it to Benchmark to get it black-if-field, tested, and shipped to me. It would still be a savings over a new unit.

Also in the running are the ATI 1802 and ATI 522NC (N-Core). Suggestions?

- Rich

Interestingly, the ATI N-Core uses linear power supply but class D/switching amplifier. The Benchmark uses switching power supply but linear/class AB amplifier on Class H power rails. Regardless, if you want to go for the best specs on paper, go for the ABH2 as long as 100W/190W 8/4 ohm is more than enough for you.
If you are fine with the lesser specs on paper but believe the difference is theoretical but not audible, then go for the ATI that offers much better $/W, and the specs on paper are still top notch. One way to do it is to get both.

 

[PENG]

I'm sure PENG could give us more detailed answers on the technical side.

To me, a good amp has plenty of power to handle all loads, even 1 ohm loads.

For example, McIntosh amps are very good amps. But they will output the same power into 8 ohms as 4 ohms and 2 ohms (like 300 Watts into 8/4/2 ohms). They don't have to "double-down".

If your speakers are 8 ohms and have a sensitivity of 88dB/w/m and you sit 3 meters away and wanted 100dB, your amp would need to output 143 Watts to produce 100dB.

But if you had this $3K Benchmark amp, it would clip at 108 Watts into 8 ohms.

What good is the "double-down" spec when it clips at 108 watts?

So it depends on the case.

You got everything covered but I would add the following:

- While I agree that a good amp should be able to deal with 1 ohm, they can do so for a very short duration only, I am talking may be a few millisecond. I would think that most AVRs, even a lot of modern power amps, would trip the protective circuit right away as they would see the 1 ohm load as a short circuit. As you know, my AVR-3805 in fact did pass the 1 ohm test, but back then the protective circuits didn't work all that well.

- Most McIntosh amps use what they call autoformer (autotransformer) that allows them to have the same rated output for 8/4/even 2 ohms. That doesn't mean they don't have higher dynamic output capability, and they actually do, I saw some bench test data so I know they do.

- If you had the $3K Benchmark amp, you just have to make sure you listen to the kind of level that I do in my rooms, where I have never seen anything higher than 50 W max, averaging fractional watt most of the time. If you do need more, then pretend it is a $6K amp, then you get 380 W and after losing 3 dB in SNR, you still have an amp that is quieter than most other power amps on the market.

The double down thing to me is too simplistic to stand on its own, for reasons you cited, and more..The Denon PMA-SX integrated amp, US$6,650 used on e-Bay is rated 50/100 W 8/4 ohm. That's double down and more than double the price of the ABH2, but would you say it is a stronger amp? I would think the ABH2 and your ATI2005 that don't double down, are the stronger amps.

 

[PENG]

@ADTG, I believe I read somewhere that one of the tell tail signs of a good amp build, is that it should be able to output two times the power output from 8 ohms into 4ohms. If I worded that right, say a amp outputs 200 X 2 at an 8 ohm load, a good amp build should output double that into a 4 ohm load. Would that be correct? also say a amp that can't output two times the output into a 4 ohm load, Now my question, would it be because of #1, smaller power supply, #2 power trans at the rail? and #3, smaller Caps ufs?. just trying to gain some knowledge on amp build.

Manufacturers rate their amps output power based on their output voltage and current capability, everything else being equal. For a resistive load, a 200 W into 8 ohm amp will have output voltage of 40V and current would be 40/8=5A (Ohm's law). Reduce the load to 4 ohm while keeping the same voltage will result in a higher current of 40/4 = 10A.

Power = Voltage X Current (for resistive load only), so using the example above.

8 ohm load: Power = VXI = 40X5 = 200 W
4 ohm load: Power = VXI = 40X10 = 400W, that is, "Double down".

So for a power amp to claim double down from 8 to 4 ohm, they just have to have the power supply and output device rated for the higher current due to the lower resistance, assuming the voltage drop due to increased current is negligible. If not, then a regulated power supply could be used to keep the voltage independent of the load impedance within the designed range.

The same applies to reactive loads, except that we should then refer to VA (volt-ampere) instead of Watts. Now you can why transformers are rated in VA, not Watts. To double down from 8 to 4 ohm impedance (for reactive load), the transformer will have to have the required VA rating and the output devices will have to be rated for the higher current due to the lower (half) impedance.

Regardless, a 200/300W 8/4 ohm rated amp is obviously stronger than a 100/200W 8/4 ohm or 150/300W 8/4 ohm amp that can claim double down capability. So manufacturers could choose to manipulate the specs if they wish to make the double down claim too.

 

[PENG]

You don't eat in the office every single day like me?

Sorry, I am only an engineer, not a Pharmacist who has to take care of people's health need in real time.

 

[PENG]

I still think if you are getting an amp, it better be 200W/8 ohms or more!

I think it's ridiculous to get a 100W/8 ohms amp when most AVRs can output more than that!

Jokes aside, while that is true but no AVRs will come close to the ABH2's pristine SNR/THD+N specs, audible or not is a different story for a different thread. The only AVR that could come close is the Denon AVR-5805MKII. That AVR actually doubled down on Gene's bench too, but the ABH2 still beat it in THD+N in significant way.