AVR distortions from entry level to top level models

[highfigh]

To be fair, there isn't some great mystery surrounding amp technology. This has been down pat for several decades now. It's like you almost have to try to build a truly bad amp!

Now, you've gone and done it! Nice knowing ya!

Wait- this isn't one of the tweak forums, so it's OK that you posted this.

Lack of budget makes it hard to make a good amplifier and if the manufacturer wants to place more emphasis on the bells & whistles and video, sound quality ends up in the rumble seat on a rainy day.

 

[highfigh]

THD + N is the single most important spec on the entire spec sheet!

I don't even look at 1% THD + N. The spec that I follow is 0.1% THD + N

I would place THD+N at about equal to TIM since we don't listen to pure tones (usually). With some synth music, it can be difficult to keep it clean but with more complex music and lots of instruments, it's not always easy to hear unless it's dissonant.

 

[PENG]

I have one, too. I was using it for 2 channel and 2.1 until I started carrying Parasound and I think it sounded good, for an AVR that has to budget money for all of the extra channels, video switching and processing, AirPlay (which isn't cheap), DAC, two zones, etc. I had an AVR-990 before the 2313CI and that sounded good, too.

The sound quality is one of the reasons I haven't looked for other brands of receivers- I haven't seen anything that does video or audio better at the price, but I haven't tested Marantz, either.

I remember we have had a brief friendly exchange on sound signatures when you talked about the Marantz sound. Before you actual get a Marantz and start comparing, I hope you will read the articles I linked earlier. The guy used to be McIntosh's acoustic research director and had designed amps and speakers while there. He is the only one from the manufacturing side who talked about the importance of doing blind comparison tests and to do it properly. He also said though he thought he could hear differences between good amps, he only got it right about 50% of the time. Lastly, he actually did try to define what is considered "good" amp.

 

[AcuDefTechGuy]

What is the THD on speakers (frequency, dB)?

Can we really tell the difference between 0.1% vs 1% THD in AVR/amps with most speakers, frequencies, dB?

 

[highfigh]

I remember we have had a brief friendly exchange on sound signatures when you talked about the Marantz sound. Before you actual get a Marantz and start comparing, I hope you will read the articles I linked earlier. The guy used to be McIntosh's acoustic research director and had designed amps and speakers while there. He is the only one from the manufacturing side who talked about the importance of doing blind comparison tests and to do it properly. He also said though he thought he could hear differences between good amps, he only got it right about 50% of the time. Lastly, he actually did try to define what is considered "good" amp.

I think listening tests should be blind, too but as I wrote when I signed on as a Parasound dealer and heard the major differences in sound between that and my Denon, I think most of it is in the preamp, although the Parasound power amp does drive low impedances more easily- the rated output into 8 Ohms is >30% higher (125W/ch) and its 4 Ohm rating is 225W/ch so even at the levels I used the Denon, the Parasound wasn't breaking a sweat and when I push it, it does things the Denon never could. If the Parasound had the same ratings, it would be a more fair test but I didn't sign up with them so I could find equivalent items, I wanted a good sounding two channel line with specific features that most of the other brands don't have. I looked at a lot of brands and none had the number of inputs I wanted and most that have a phono section don't do MC, which I need AND want. Ironically, Denon doesn't and they make one of the best bargains in MC cartridges with their DL-103R.

One of the benefits of changing one piece of equipment at a time is that if any sonic differences are noticeable, it's easier to guess at the reason(s). If the AVR-2313CI had main pre-outs, I could have connected the power amp first and compared the sound but it only has Zone 2 pre-out and doesn't send the audio from digital inputs to Zone 2

 

[highfigh]

What is the THD on speakers (frequency, dB)?

Can we really tell the difference between 0.1% vs 1% THD in AVR/amps with most speakers, frequencies, dB?

When analog sources were all that was available, none of the tests concluded that people, even those experienced in critical listening, could say that the sound was distorted, even when it was over 1%. Cassette and phono typically operate in the 1-1.5% range when the level was around 0VU and when the distortions from all of the components in the system were stacked, it still wasn't obvious. We focus on some aspects of the sound and ignore others- our minds are as much a part of the experience as anything else.

 

[PENG]

Just added the AVR-4308 CI that I did own and replaced with the Marantz 8801.

The reviewer said:

"This graph shows that the AVR-4308CI's left channel, from Multi input to speaker output with two channels driving 8-ohm loads, reached 0.1% distortion at 198.6 watts and 1% distortion at 218.9 watts. The distortion level remained at or below 0.002% across all power levels until it reached about 165 watts. Into 4 ohms, the amplifier reached 0.1% distortion at 298.0 watts and 1% distortion at 343.4 watts.

With five channels driven continuously into 8-ohm loads, the receiver reached 0.1% distortion at 144.8 watts and 1% distortion at 173.6 watts. With seven channels driven continuously into 8-ohm loads, it reached 0.1% distortion at 124.5 watts and 1% distortion at 150.3 watts.

The manufacturer's specs indicate a power output of 140 watts into 8 ohms with a distortion of 0.05% (number of channels not specified). With seven channels driven into 8 ohms, the receiver reached distortion of 0.05 % at 116.4 watts, which is 83% of the rated power at that level of distortion."

Read more at http://www.soundandvision.com/content/denon-avr-4308ci-av-receiver-measurements#Jxwbv8Yy18zcYjit.99

I guess Gene was right, the older Denon were even better. The 4308 has no fans either.

 

[PENG]

When analog sources were all that was available, none of the tests concluded that people, even those experienced in critical listening, could say that the sound was distorted, even when it was over 1%. Cassette and phono typically operate in the 1-1.5% range when the level was around 0VU and when the distortions from all of the components in the system were stacked, it still wasn't obvious. We focus on some aspects of the sound and ignore others- our minds are as much a part of the experience as anything else.

And Roger Russell quoted Stereo Review's Julian Hirsch:

"It came as no surprise that all the amplifiers in this group were capable of delivering excellent performance in almost any home music system. And provided we kept all of them running within their power limits, we heard nothing that would incline us to prefer one over another. Although some people strongly feel otherwise, good amplifiers of comparable quality and power that are not being overdriven will sound very much alike under most conditions to most people. If amplifiers do sound much alike (and these did), then why bother comparing them? Because there is more to an audio component than the perceived sound character. There are differences in operational limits (maximum power output into various loads, for example), construction quality and finish, size, weight, price and features that can affect an amplifier's suitability for any particular installation."

For those who did want to read the linked long article, Mr. Russell said:

"I think that differences are understandable. An amplifier having 0.1% distortion and one having 0.001% distortion are clearly not the same but they are way below audibility. An amplifier having a damping factor of 10 and one having a damping factor of 1000 are also not the same but once again the difference is not audible.

I have personally completed several blind A-B listening tests over the years between good amplifiers, tube or transistor. Although I thought I could hear a difference each time, my choice was only correct about 50% of the time. I have also conducted blind listening tests for other people. I have learned how important it is to set the amplifier gains to be exactly equal and that the amplifiers should not be seen or identified for the listener. The slightly louder amplifier often is preferred. Comparison must be instantaneous or the listener forgets. If the identity of the amplifiers is known, the listener often gets preoccupied with identifying which amplifier is playing instead of the sound quality. The questions asked of the listener about the sound quality are also very important. I even hide the speakers as well as the amplifiers behind an acoustically transparent curtain."

Coming from someone who is an EE and have designed McIntosh amps and speakers, I find that quite interesting.

 

[AcuDefTechGuy]

I guess Gene was right, the older Denon were even better. The 4308 has no fans either.

One reason I am not replacing my AVP-A1HDCI or AVR-5308CI anytime soon for any DTS:X, ATMOS, 3D video or 4K video.

 

[AcuDefTechGuy]

And Roger Russell quoted Stereo Review's Julian Hirsch:

"It came as no surprise that all the amplifiers in this group were capable of delivering excellent performance in almost any home music system. And provided we kept all of them running within their power limits, we heard nothing that would incline us to prefer one over another. Although some people strongly feel otherwise, good amplifiers of comparable quality and power that are not being overdriven will sound very much alike under most conditions to most people. If amplifiers do sound much alike (and these did), then why bother comparing them? Because there is more to an audio component than the perceived sound character. There are differences in operational limits (maximum power output into various loads, for example), construction quality and finish, size, weight, price and features that can affect an amplifier's suitability for any particular installation."

For those who did want to read the linked long article, Mr. Russell said:

"I think that differences are understandable. An amplifier having 0.1% distortion and one having 0.001% distortion are clearly not the same but they are way below audibility. An amplifier having a damping factor of 10 and one having a damping factor of 1000 are also not the same but once again the difference is not audible.

I have personally completed several blind A-B listening tests over the years between good amplifiers, tube or transistor. Although I thought I could hear a difference each time, my choice was only correct about 50% of the time. I have also conducted blind listening tests for other people. I have learned how important it is to set the amplifier gains to be exactly equal and that the amplifiers should not be seen or identified for the listener. The slightly louder amplifier often is preferred. Comparison must be instantaneous or the listener forgets. If the identity of the amplifiers is known, the listener often gets preoccupied with identifying which amplifier is playing instead of the sound quality. The questions asked of the listener about the sound quality are also very important. I even hide the speakers as well as the amplifiers behind an acoustically transparent curtain."

Coming from someone who is an EE and have designed McIntosh amps and speakers, I find that quite interesting.

Roger Russell could have 10 PhD degrees and conducted 50 DBTs in all 50 states using 1,000,000 subjects and some people still wouldn't believe him.

 

[PENG]

There are many more boutique brand dealers, resellers than the like of Russell, Floyd, Clark etc. I have no regret on my Bryston though, it doesn't sound better than my cheaper amps but I know it won't deteriorate over a long period of time. When it does, I'll send it back for a restore.

 

[highfigh]

Coming from someone who is an EE and have designed McIntosh amps and speakers, I find that quite interesting.

I have read a lot of what Roger Russell's comments and it's great to see reason applied to what he did. OTOH, I can't think of anyone who decided to produce a product and market it by saying "Ours are just as good as theirs". What had been mass-merchandised audio equipment from Japanese manufacturers in the '70s and '80s is now seen as "The.Best.Ever." and there's no way a Pioneer SX-1250 should be selling for over a grand, but here we are and that model, which was good but nothing amazing, is selling for over a grand. Audio Karma and Facebook are the cause, IMO, but logic has little to do with this phenomenon- it's just herd mentality. I looked a couple of days ago and found that the SX-1980 is now selling for more than $5000 and that's insane! IT WASN'T THAT GOOD!!!!!!

I went to a gathering at the local McIntosh dealer in about 1980 and Len Feldman (designed equipment for Fisher during the '50s, EE, member of the AES and IEEE, etc) was the featured speaker. He told us that amplifiers sound alike, but many of us didn't agree. Compare a Sony with Pioneer, Marantz, Sansui, HK or other receiver or separates from that time and differences will be heard. His conditions must have been far more controlled than ours but we did have a switching system that didn't seem to screw up the sound and when one button was pushed, it canceled the other, so we could use the same speakers or source.

Could those of us who sold this equipment in the past have been just as influenced by the marketing? Sure. Do I still think I hear differences between one piece and another? Absolutely. Do I know EXACTLY why I hear a difference? Not necessarily.

As an EE, do you agree with the reasons many of the cable manufacturers make their cables the way they do? Every EE I have asked about AQ's cables with batteries looked at me like I had three heads when I told them "the batteries are there to decrease/eliminate cable break-in and to bias the dielectric" (AQ's description, not mine). What are your thoughts on this?

 

[highfigh]

There are many more boutique brand dealers, resellers than the like of Russell, Floyd, Clark etc. I have no regret on my Bryston though, it doesn't sound better than my cheaper amps but I know it won't deteriorate over a long period of time. When it does, I'll send it back for a restore.

You would have been amazed by a system I worked on after the original installation. I think I counted at least 15 Bryston stereo power amplifiers for the distributed audio and when I looked behind the rack, I saw that about half of them had Radio Shack isolators connected. Nice. Really nice. They do work, thought.

I would like that 20 year warranty on the Bryston, though.

 

[highfigh]

Roger Russell could have 10 PhD degrees and conducted 50 DBTs in all 50 states using 1,000,000 subjects and some people still wouldn't believe him.

 

[PENG]

As an EE, do you agree with the reasons many of the cable manufacturers make their cables the way they do? Every EE I have asked about AQ's cables with batteries looked at me like I had three heads when I told them "the batteries are there to decrease/eliminate cable break-in and to bias the dielectric" (AQ's description, not mine). What are your thoughts on this?

If you are serious, I can't comment on something I don't know anything about. I would have to read through AQ's literature, before I could even say whether I understand why they did what they did. As it is now, I don't really know what they are doing with those "battery biased" cables. But you weren't serious are you?

 

[highfigh]

If you are serious, I can't comment on something I don't know anything about. I would have to read through AQ's literature, before I could even say whether I understand why they did what they did. As it is now, I don't really know what they are doing with those "battery biased" cables. But you weren't serious are you?

Unfortunately, I am serious.

http://www.audioquest.com/wp-content/uploads/2011/12/DBS.pdf

I'm trying to figure out why their 6' HDMI cables can cost $1500.00 and no, I didn't misplace the decimal. I'd have thought they would use high-end batteries, though. They're the same ones used in a lot of garage door remote controls.

 

[3db]

Peng, thanks for posting all of those graphs and to tyhjaarpa for attempting to put them all in one graph to make comparisons easier. Pushing the entry level receivers aside for the moment because of severe budgetary constraints placed on them, my take on all of this that ALL the AVRs had inaudible levels of distortion well within their power envelopes. They ALL performed extremely well IHO. Its only when one begins to approach the limits of the power envelope do the distortion levels rise. To me the extra money spent on the power supply and the amp section is illustrated in pushing out the positive slopes of rising distortion further to the right. The Denon 28XX is the exception here. Its distortion curves are ultra low through a greater part of its power envelope but the slope once crossed rises faster than the others.

I will never purchase an AVR based on the lowest levels of distortion well with its in power envelope as anything below .05% is inaudible. Its a waste of money. I would buy an AVR based on its behaviour when approaching its power limits combined with the feature set, build quality, and customer service.

 

[KEW]

I seemed to remember Kurt has one of those, yes/no? If yes, any comments on that low cost unit?

LOL, so I hooked it up and gave it a good check out and I can say irrefutably that it works as well as my other AVR's. I suspect if I really wanted to, I could mate my 50WPC Marantz NR1605 (which I bought to use with a separate amp) with my Phil3's and then use the 2308 for the Phil3's and note how the 2308 does better at high volumes.
As far as detecting sound character differences, I once compared a couple of amps using two pairs of identical speakers. I was amazed to hear a distinct difference until I determined that the difference in sound was due to the speaker positions. The better sounding system was always determined by the speaker location.

 

[KEW]

Peng, Thank you for sharing all of this information with us!
I'm sure I'm not alone and there are many appreciating the research you have presented here!

 

[PENG]

Unfortunately, I am serious.

http://www.audioquest.com/wp-content/uploads/2011/12/DBS.pdf

I'm trying to figure out why their 6' HDMI cables can cost $1500.00 and no, I didn't misplace the decimal. I'd have thought they would use high-end batteries, though. They're the same ones used in a lot of garage door remote controls.

Thanks highfigh, I read the write up in the link but I won't be digging deeper because they are talking about dielectric, not the conductor. I do have books on electrical engineering materials that get deep into topics such dielectrics but I just don't see the link between the dielectric properties and sound quality in home audio. The insulated part of the cable is the dielectric and it affects mainly the capacitive characteristic that will naturally be negligible for relatively short lengths. We are not talking about long runs of high power cables or transmission lines here. It seems to me those guys are just making things up in order to sell to the uninformed.

If you can sell those to the believer though, I am sure the margins on such products will be great and the believers will hear a difference because they believe.