ashok said:
I'll do both. Actually, it needs a web page of instructions for how to use it properly so you can get the measurements (eg, you can use a regular sound card, but you'll need an opamp buffer, stuff like that). The software just does a little simple math and plots the results all pretty.
the technical papers at
http://www.mp3-tech.org/
might be a useful introduction to the research literature that could be relevant to amplifier "audibility" - is an amp is "more transparent" than a high bit rate codec?
http://www.mp3-tech.org/
might be a useful introduction to the research literature that could be relevant to amplifier "audibility" - is an amp is "more transparent" than a high bit rate codec?
SleeperSupra said:
As is typical with these threads, the OP is all but forgotten, breaking down into claims of I can hear this and you can't hear that. I've posted it above as a reminder.
Does anyone have any scientific data to dispute or refute what is spelled out above? Not your personal feelings, emotions and beliefs. This is not about a violin or a soprano. It's about a part of an electronic reproduction chain. Whether you believe it or not, science applies. Anyone?
panomaniac said:
tinitus said:
Would either one of you please quote or post a link to who or where this was said? Thanks.
cheers,
AJ
$5 for a member if the article is not in the very last journal, I think.eStatic said:
He doesn't have to coerce me...bear said:
Back in the nineties the japanese amps came forward with 0.000003% distortion, and so forth. So based on that, the differences must be based on imperfections.
Now the problem is to figure which imperfections it is we seem to like 😉
Magura 🙂
Now the problem is to figure which imperfections it is we seem to like 😉
Magura 🙂
Certainly arguments have been presented that these measurements do not capture everything, such as memory distortions. I think you're jumping the gun with your comment until such arguments have been satisfactorily discounted.
tinitus said:
And only valid for whatever speaker is used (and cable)... the amp/speaker has to be considered as a system.
dave
planet10 said:
But, as I'm sure you know, this is not a problem in principle. As we are talking about amps, starting with a good cable and speaker and holding those constant provides an adequate base for that determination. If it is found that all good amps sound the same then different speakers could be tried to see if they are masking differences. And if they are not we can call in the mystics to bring their favorite cables for testing.
There are two ways of selecting a system to prove the point.
1. If you want to prove amps sound the same:
Use a low quality CD Player with low quality cable and slow low resolution speakers and select some slow "simple" music for the test.
2. To prove amps don't sound the same:
Use a high quality CD Player with good cable and some revealing speakers and play fast dynamic music, with a number of instruments playing together, for the test.
I'm convinced either one will work.
André
1. If you want to prove amps sound the same:
Use a low quality CD Player with low quality cable and slow low resolution speakers and select some slow "simple" music for the test.
2. To prove amps don't sound the same:
Use a high quality CD Player with good cable and some revealing speakers and play fast dynamic music, with a number of instruments playing together, for the test.
I'm convinced either one will work.
André
Andre Visser said:
how about the Stereophile/Carver Challenge then?
http://www.diyaudio.com/forums/showthread.php?postid=152392#post152392
explained by "low resolving" equipment?
or the psychological stress of asking professional audio reviewers to do what they claim is their job?
jcx said:
jcx, after reading that I can give my personal opinion of why it was possible for Carver to duplicate the sound with his cheap amp. Only problem is I'm going to get lots of s**t from a lot of guys. Here is it and then I will run 😀.
The amp they gave him to copy fall in the first group of my statement. I don't think it is difficult to make a solid state amp sound like valves, the other way round I don't think is possible.
Please, I don't want to argue with you guys, I'm just stating my experience and thoughts. Also the fact that Carver had to modify his amp to sound like the other is prove in itself that amps do not sound the same.
André
It is this part that cracks me up:
"Not surprisingly, the reference amplifier sounded very different [from the Carver] and, in our opinion (shared, in most respects, by Bob), much better."
Ok, end of test.
"Bob didn't have to concern himself about quality capacitors, minimal internal wiring, gold connectors, or any of those things; all he needed to do was duplicate, at the output of his amplifier, the sum of their effects at the output of the reference amp. Once he had obtained the necessarily deep null between those amplifiers, it was his belief that ears were not going to pick up on what was left."
Oh wait, let me mod my amp and make it sound DIFFERENT. What is the point here? Are you comparing amps or are you modding amps to sound the same and then seeing if they don't???? I have two cars that go 100 and 200mph, and if I set the cruise control in each to 60mph I bet they both go 60. Should call this the Homer Simpson test. Who would care if you could hear a difference since you are EQing the amps anyway, I can do that any time.
"Not surprisingly, the reference amplifier sounded very different [from the Carver] and, in our opinion (shared, in most respects, by Bob), much better."
Ok, end of test.
"Bob didn't have to concern himself about quality capacitors, minimal internal wiring, gold connectors, or any of those things; all he needed to do was duplicate, at the output of his amplifier, the sum of their effects at the output of the reference amp. Once he had obtained the necessarily deep null between those amplifiers, it was his belief that ears were not going to pick up on what was left."
Oh wait, let me mod my amp and make it sound DIFFERENT. What is the point here? Are you comparing amps or are you modding amps to sound the same and then seeing if they don't???? I have two cars that go 100 and 200mph, and if I set the cruise control in each to 60mph I bet they both go 60. Should call this the Homer Simpson test. Who would care if you could hear a difference since you are EQing the amps anyway, I can do that any time.
cabbagerat said:
Exactly
Tell me the logic here, Carver downgrade his amp by putting a resistor in the output to lower damping factor and change the freq response with a LC filter in the feedback, then the "worse sounding" amp all of a sudden sound the same as the "better" one. Sorry 1 and 1 doesn't make 2 here.
one thing that has an effect on sound between two amplifiers, even two consecutive serial numbered ones, is component tolerances. typical component tolerances on mass produced amplifiers are:
resistors +/-5%
capacitors:
solid +/-5%, with other variations due to dielectric type
electrolytic +20%/-10% (a 30% range)
transistors: beta can vary A LOT. a typical range is 30-150 for MJ15022/23's with the "spec" at 75. that's +100/-60%.
matching can be expensive and time intensive for a manufacturer. when i worked at APT in the 80's, the parts buyer switched from MOT factory preselected output devices to bulk orders from a distributor, just to save a few bucks. when it became evident that only about a third of the bulk transistors were usable in the amplifiers because the beta had to be 75 or less, it turned out we spent more per amplifier after factoring in the 2/3 loss of savings for the unusable transistors. plus the labor to test them. and this wasn't even beta matching, just checking to see if it's less than the maximum allowable value.
resistors +/-5%
capacitors:
solid +/-5%, with other variations due to dielectric type
electrolytic +20%/-10% (a 30% range)
transistors: beta can vary A LOT. a typical range is 30-150 for MJ15022/23's with the "spec" at 75. that's +100/-60%.
matching can be expensive and time intensive for a manufacturer. when i worked at APT in the 80's, the parts buyer switched from MOT factory preselected output devices to bulk orders from a distributor, just to save a few bucks. when it became evident that only about a third of the bulk transistors were usable in the amplifiers because the beta had to be 75 or less, it turned out we spent more per amplifier after factoring in the 2/3 loss of savings for the unusable transistors. plus the labor to test them. and this wasn't even beta matching, just checking to see if it's less than the maximum allowable value.
jol50 said:
Like I said above.
Sure manufacturing tolerances could make a usually small difference, but remember we are talking about 'quality' amps here that meet his criteria. Most of the new cheaper HT amp I have seen use a big IC. I assume they have better matching/quality control but I don't really know for a fact.
eStatic said:
What defines a good speaker. I build speakers that like higher output impedance amps -- use a low output impedance amp and the system sounds thin and 2D.
Or take a high efficiency speaker and use it with a monster amp, or a low efficiency, complex XO speaker and mate it with a small amp.
All of these situations point out that the amp & speaker are a system and cannot be considered spearately.
Cables are part of that system too. A favorite cable only works with the amp & speakers it is a favorite with. Change the amp or the speaker and it may well not be very good.
dave
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