All amps sound the same??? (Read Inside)

[Seth=L]

Thread derailed....

 

[costanza]

I think the Panasonic Class D receivers were far from refined.

Which ones did you listen to and with what speakers?

Earlier today, I swapped out my XR57 for an XR10 driving my Primus 250's, and went to do other stuff around the house with some vocal/jazz music playing from one of my cable services music channels (2.0 Dolby Digital). It sounded good, so I went over and actually LISTENED to it. I was very impressed! It sounded so natural

I didn't WANT it to sound better. But I think it did, in this particular case. I actually want the XR57 to sound better, if that makes any sense. It's newer and has so many more features, including a display that's actually legible from more than 1 ft. away! The XR10 is as basic as could be.

 

[Boerd]

You mean a hammer blow sounds different on their chassis?

Ha ha ha - good one.
Actually I had a Marantz (499$) that pushed hard was more stable than the I21 (1499$) from Primare - meaning Primare had less juice and clipped at lower volume than the Marantz while rated at higher W.

 

[costanza]

I compared an XR10 to an XR57 last night through a pair of Primus 250's in full range stereo via optical input. I ran speaker wires from the outputs of the receivers to 2 separate sets of binding posts that were resting in my lap. I had the set of banana plugs from the speakers in my lap as well. I first made sure the receivers were level matched. I then swapped the binding posts in my lap around several times to confuse me as to which was which in relation to the receiver they were going to. I then marked one with a rubber band to differentiate one from the other. I listening to music and voices from TV shows while swapping the banana plugs from one set of binding posts to the other. Result? They sound VERY similar on some music, but I did notice the "rubber band" receiver had a brighter top end (me no likey) and forward midrange (me likey). Bass was pretty equal. The "rubber band" receiver turned out to be the XR10. This verified what I had previously noted from a "sighted" comparison... vocals sounded better from the XR10. I'm gonna do a similar test tonight pitting the XR57 against a Denon AVR2803 in DIRECT mode.

 

[KEW]

I compared an XR10 to an XR57 last night through a pair of Primus 250's in full range stereo via optical input. I ran speaker wires from the outputs of the receivers to 2 separate sets of binding posts that were resting in my lap. I had the set of banana plugs from the speakers in my lap as well. I first made sure the receivers were level matched. I then swapped the binding posts in my lap around several times to confuse me as to which was which in relation to the receiver they were going to. I then marked one with a rubber band to differentiate one from the other. I listening to music and voices from TV shows while swapping the banana plugs from one set of binding posts to the other. Result? They sound VERY similar on some music, but I did notice the "rubber band" receiver had a brighter top end (me no likey) and forward midrange (me likey). Bass was pretty equal. The "rubber band" receiver turned out to be the XR10. This verified what I had previously noted from a "sighted" comparison... vocals sounded better from the XR10. I'm gonna do a similar test tonight pitting the XR57 against a Denon AVR2803 in DIRECT mode.

I like your approach to a "virtually blind" test. Arguably, your subconscious could know which was which, but I think it is a pretty sound approach. I believe the differences you are hearing are real.
However, in the context of the original post, you are not comparing two amps, but instead two receivers which include the pre-amp section. You won't find too many people who will argue that pre-amps don't effect sound.
In the case of the Panasonics, they may well have deliberately colored the sound to better complement the type of 5.1 speaker system which would typically be used.

But please let us know what you find with the Denon comparison.

 

[mtrycrafts]

.... You won't find too many people who will argue that pre-amps don't effect sound.

Why would they sound different? By intentional design? Then, that would certainly show up on the spec sheet, no?

In the case of the Panasonics, they may well have deliberately colored the sound to better complement the type of 5.1 speaker system which would typically be used.
....

How would Panasonic know which 5.1 speakers would be used? And how would they know which room those speakers are placed in? Doesn't happen like that at all. I bet the Panny pre is transparent as well.

 

[PENG]

You won't find too many people who will argue that pre-amps don't effect sound.

For line level inputs, a reasonably well designed (I know this may not be simple to define) preamp should not affect the sound as much as a power amp will, though in either case it will be hardly noticeable by people who do not possess golden ears. This, of course can only be said if all sound processing and tone controls are defeated, sort of like pure direct mode in receivers. If any tone controls and sound processing are engaged then preamp/prepro will certainly affect the sound more so than power amps.

 

[mtrycrafts]

I compared an XR10 to an XR57 last night through a pair of Primus 250's in full range stereo via optical input. I ran speaker wires from the outputs of the receivers to 2 separate sets of binding posts that were resting in my lap. I had the set of banana plugs from the speakers in my lap as well. I first made sure the receivers were level matched. I then swapped the binding posts in my lap around several times to confuse me as to which was which in relation to the receiver they were going to. I then marked one with a rubber band to differentiate one from the other. I listening to music and voices from TV shows while swapping the banana plugs from one set of binding posts to the other. Result? They sound VERY similar on some music, but I did notice the "rubber band" receiver had a brighter top end (me no likey) and forward midrange (me likey). Bass was pretty equal. The "rubber band" receiver turned out to be the XR10. This verified what I had previously noted from a "sighted" comparison... vocals sounded better from the XR10. I'm gonna do a similar test tonight pitting the XR57 against a Denon AVR2803 in DIRECT mode.

How did you level match the two? At what frequencies? I question your protocol as you compared.

Perhaps next time you could have two DPDT switches, mark left speaker on one and right speaker on the other, then one side of each switch is marked receiver A, the other B and make sure it is properly wired. Then, have someone else control the switching after training so the left and right speakers are run by the same receiver or just use a single 4 pole double throw switch, simpler. Have the other person out of sight, flip coin for a sequence of 16 or 20 trials and see how many you can guess correctly. After the trials, compare the sequences.

 

[costanza]

I level matched with an analog RS spl meter and pink noise fed to both receivers from a Stereophile test CD. After I level match and swap the binding post sets around a few times, I have no idea which set goes to which receiver. At the end of the test, I leave the banana plugs connected to the set of binding posts going to whichever receiver I preferred the sound of and then turn down one of the 2 receivers to reveal the "winner". I definitely agree that having someone else to throw in some "placebo" switching would be more accurate, but I have to make do on my own.

Anyway, after about an hour of listening to the Denon 2803 and the XR57 last night, I came to the conclusion that they sound virtually identical with these Primus 250's! I was really shocked at this result. I had heard more treble from the XR57 compared with this Denon when using a pair of Definitive BP6B's. I *think* the XR had an ever so slight "cupped hands" coloration in the mids, but I only occasionally heard it. I'm gonna do some frequency measuring tonight for kicks. I picked up a cheap HK AVR 330 that should be in my hands next week. I'll post the results of that comparison. By the way, I noticed my Denon was made in Japan. That's always nice

 

[mtrycrafts]

I level matched with an analog RS spl meter and pink noise fed to both receivers from a Stereophile test CD.

Thanks for the response. Unfortunately that is not an accepted method for level matching or rather checking.
Single frequency tones like say, 100 Hz, 1kHz and 10kHz and a good voltmeter checking the voltage at the speaker terminal to 1% or less difference.

 

[costanza]

Thanks for the response. Unfortunately that is not an accepted method for level matching or rather checking.

It's acceptable to me This isn't some life or death, lab experiment. It's a casual hobby. I'm just sharing my experiences for those that care.

 

[Pyrrho]

It's acceptable to me This isn't some life or death, lab experiment. It's a casual hobby. I'm just sharing my experiences for those that care.

What it means is that you may hear a difference due to the levels not being matched, so hearing a difference between them shows absolutely nothing about the sonic characteristics of the amplifiers. (Part of the reason for that is due to some peculiarities of human hearing; as the volume decreases, subjectively, the bass and treble appear to decrease more than the midrange, so a change in volume is perceived as a change in tonal quality. This is why so many old stereos had "Loudness Compensation" switches on them, to boost the bass and treble to make up for listening at low volumes and make it seem better.) You may not care if you are wrong, but many people do care when people publicly post falsehoods. What is the point in posting things that are without foundation in fact and reality?

Sure, it is not life or death. But that is no reason to accept falsehoods and illusions.

 

[costanza]

What it means is that you may hear a difference due to the levels not being matched, so hearing a difference between them shows absolutely nothing about the sonic characteristics of the amplifiers. (Part of the reason for that is due to some peculiarities of human hearing; as the volume decreases, subjectively, the bass and treble appear to decrease more than the midrange, so a change in volume is perceived as a change in tonal quality. This is why so many old stereos had "Loudness Compensation" switches on them, to boost the bass and treble to make up for listening at low volumes and make it seem better.) You may not care if you are wrong, but many people do care when people publicly post falsehoods. What is the point in posting things that are without foundation in fact and reality?

Sure, it is not life or death. But that is no reason to accept falsehoods and illusions.

The receivers' volumes were adjusted so that the pink noise was equal according to the spl meter. I also did some high and low frequency test tone readings as well and both receivers were giving identical numbers. I'm confident that they are level matched. If no one else is, that's their issue, not mine
Anyway, I did some more listening. I noticed one of the receivers had a slight forward quality that gave the music more realism. Basically, I was enjoying listening to it more than the other. That receiver turned out to be the XR. I'm gonna do a few more tests like these and see if I keep coming to the same conclusion.

 

[AJinFLA]

I'm gonna do a few more (invalid) tests like these and...keep coming to the same (forgone) conclusion.

Fixed it for ya

 

[mtrycrafts]

It's acceptable to me ...

That is all that is needed for a singular reality.

 

[ichigo]

Amps might have different distortion characteristics--how the even and odd order distortions break down, as well as the amplitude of individual distortions--higher order distortions sound considerably worse than lower order distortions at the same SPL.

But I don't think these characteristics will truly manifest unless you are listening at fairly high levels, say 85db+

 

[costanza]

I didn't get a chance to do any comparative listening last night, but I did listen to the XR57 with my old pair of Def Tech BP6B's in a much larger room that would be considered very "live". It sounded awful! Bass was weak and I had to turn the treble tone down to -2 to tame the highs.

 

[AcuDefTechGuy]

I didn't get a chance to do any comparative listening last night, but I did listen to the XR57 with my old pair of Def Tech BP6B's in a much larger room that would be considered very "live". It sounded awful! Bass was weak and I had to turn the treble tone down to -2 to tame the highs.

How did you place those speakers?

6" from the front & side walls?

12"?

18"?

36"?

 

[Seth=L]

I didn't get a chance to do any comparative listening last night, but I did listen to the XR57 with my old pair of Def Tech BP6B's in a much larger room that would be considered very "live". It sounded awful! Bass was weak and I had to turn the treble tone down to -2 to tame the highs.

Well that was an accoustic problem, not a fault of the receiver.

 

[Dr bud]

I don't have a golden ear,but i would say i have definitaly noticed differences in some of the amps of had pass through my system using all the same other gear only changing the amp.Some seem to have better driver control,clarity, etc.Jmo.Could be in my mind.After a few captain and cokes it might be harder to tell