Hertz vs Kenwood Amps
12-17-2008, 08:40 PM
#22
This is off the beaten track from the original topic... I guess it has value (for the 100th time it has come up). Pardon me while I give a partial history lesson.
The basic amplifier block diagram design has changed very little in 30 years, there are significant advances in many of the basic blocks though, particularly in power supplies and distortion performance. The basic audio gain stage is the transistor (not so much tubes or mag-amps anymore) and transistors in audio use now include bipolar, mosfet, and IC types with each having their place but all is not equal here some are better at heat rejection and others at cost and miniaturization (IGBT are still on the outside looking in). Firing circuits are much more advanced and micro-processing has made amplifier circuit boards resemble computers with upgradable boards that can be slid in. Many of the higher priced as well as higher powered amps still use point to point wiring but fewer do every year.
A lot of amps are sourced overseas, many competing amps are made off essentially the same circuit board (this has embarrassed a number of high end names when their boards were found to be a little too similar to others). So frankly the gene pool can be pretty static if you don't dictate your products content. Also certain factories have been known to substitute parts of lesser value and alter performance unknown to the 'owner' (remember the melamine in dog food and milk from China). Some factories are operated with a tremendous amount of rigor and integrity and just because a product is made in China, Taiwan, or Korea does not mean 'crappy'!!! We enjoy inexpensive wattage and better than reasonable quality for less than we would have paid 18 years ago. JMLab (Focal) and B&W are having speakers made in China that are crazy good BTW.
Given all that has changed and all that hasn't this argument is still as lively as it was in the 70's and 80's. I find it hard to believe that two amps are capable of performing the same given the variances and tolerances of 'bin' manufacturing. Bin manufacturing means your piece parts will be a common lot and will have similar tolerances (until you buy the next bin anyway). The tighter the bin performance standard the higher the cost (so even though two amps look the same, they may be built to different standards, or even have special circuits... or not). Still the most expensive item in many amps is the heat sink and the sinks performance dictates the output stages limitations (go cheap and suffer). If their electrical performance is not identical into a 4ohm resistive load then it is reasonable their performance driving a complex capacitive and inductive load would deviate even more. So from a purely logical point of view one must say it is possible that some of the deviations should be audible. But the rub comes from the measurable and repeatable thing. It has often been proven that listening levels are the most significant difference we hear. THD levels in the output are pretty much inaudible till 4-10% and the sound of THD is not what you might expect either. Stereophile (a hated audiophile magazine) publishes THE MOST comprehensive test data ever performed on amplifiers yet they are the first to admit their perceived sonic impressions are not reinforced by the measurements. To put it another way, one can not predict how an amplifier will sound from most of its specifications. MANY amps start to roll off at 18k Hz to help eliminate a HF edge so yes manufacturers do mess with measurable things to alter the sound of a linear product to make it more pleasing and yet less linear.
After all this flopping and twitching has anything been solved, if one amp out performs another does that mean we will like it more??? Yet we go to a sound board and we listen to 2 amps and we hear a difference... is it really there? Is it significant? Does negative feedback sound bad? What does an even or odd distortion product sound like? Is it due to volume/ gain differences? I think this is an individual dilemma and each individual must decide
BUT the better product might be cheaper, it might be made better, or it might be overly bass heavy and you like it that way!
I am not a big fan of specs in SQ as they don't really tell you too much and their are surprising products out there that just break the mold (boulder amps are $50,000 with IC outputs, Nuforce has a PWM power supply that measures poorly but sounds good (go figure)).
The bottom line: Buy what makes you happy
The basic amplifier block diagram design has changed very little in 30 years, there are significant advances in many of the basic blocks though, particularly in power supplies and distortion performance. The basic audio gain stage is the transistor (not so much tubes or mag-amps anymore) and transistors in audio use now include bipolar, mosfet, and IC types with each having their place but all is not equal here some are better at heat rejection and others at cost and miniaturization (IGBT are still on the outside looking in). Firing circuits are much more advanced and micro-processing has made amplifier circuit boards resemble computers with upgradable boards that can be slid in. Many of the higher priced as well as higher powered amps still use point to point wiring but fewer do every year.
A lot of amps are sourced overseas, many competing amps are made off essentially the same circuit board (this has embarrassed a number of high end names when their boards were found to be a little too similar to others). So frankly the gene pool can be pretty static if you don't dictate your products content. Also certain factories have been known to substitute parts of lesser value and alter performance unknown to the 'owner' (remember the melamine in dog food and milk from China). Some factories are operated with a tremendous amount of rigor and integrity and just because a product is made in China, Taiwan, or Korea does not mean 'crappy'!!! We enjoy inexpensive wattage and better than reasonable quality for less than we would have paid 18 years ago. JMLab (Focal) and B&W are having speakers made in China that are crazy good BTW.
Given all that has changed and all that hasn't this argument is still as lively as it was in the 70's and 80's. I find it hard to believe that two amps are capable of performing the same given the variances and tolerances of 'bin' manufacturing. Bin manufacturing means your piece parts will be a common lot and will have similar tolerances (until you buy the next bin anyway). The tighter the bin performance standard the higher the cost (so even though two amps look the same, they may be built to different standards, or even have special circuits... or not). Still the most expensive item in many amps is the heat sink and the sinks performance dictates the output stages limitations (go cheap and suffer). If their electrical performance is not identical into a 4ohm resistive load then it is reasonable their performance driving a complex capacitive and inductive load would deviate even more. So from a purely logical point of view one must say it is possible that some of the deviations should be audible. But the rub comes from the measurable and repeatable thing. It has often been proven that listening levels are the most significant difference we hear. THD levels in the output are pretty much inaudible till 4-10% and the sound of THD is not what you might expect either. Stereophile (a hated audiophile magazine) publishes THE MOST comprehensive test data ever performed on amplifiers yet they are the first to admit their perceived sonic impressions are not reinforced by the measurements. To put it another way, one can not predict how an amplifier will sound from most of its specifications. MANY amps start to roll off at 18k Hz to help eliminate a HF edge so yes manufacturers do mess with measurable things to alter the sound of a linear product to make it more pleasing and yet less linear.
After all this flopping and twitching has anything been solved, if one amp out performs another does that mean we will like it more??? Yet we go to a sound board and we listen to 2 amps and we hear a difference... is it really there? Is it significant? Does negative feedback sound bad? What does an even or odd distortion product sound like? Is it due to volume/ gain differences? I think this is an individual dilemma and each individual must decide
BUT the better product might be cheaper, it might be made better, or it might be overly bass heavy and you like it that way!
I am not a big fan of specs in SQ as they don't really tell you too much and their are surprising products out there that just break the mold (boulder amps are $50,000 with IC outputs, Nuforce has a PWM power supply that measures poorly but sounds good (go figure)).
The bottom line: Buy what makes you happy
Also, I would like to point out to used amps while we are on the quality control subject. Many people buy used amps, and there is nothing wrong there, you pay what you can afford. Some amps that are built better will have lower deterioration rate sort of speak, and offer great value, however, if you buy cheaply made amps, you're buying something that is already not performing the way it should, but it works, so you figure it's all good, but you think it sounds good, cause you just dont know any better, because you think all amps sound the same, or just never heard an amp, which is entirely on a different level of performance. Some used cheaply made amps sound like total poo, but it puts out musical noise, so many peeps are happy. Some nicely built amps can last a long time, and some start to display signs of wear within a year. Check out some signs I googled for quickly. But hey, some unexperienced folk, do not hear the signs at all, but to some they are plain as day.
http://www.instructables.com/id/S0DORU8F9T400IA/
12-17-2008, 08:54 PM
#23
Yeah, but some people have different levels of expectations from their gear, so to some virgin **** is just overkill, but magic dust will almost always yield greater results, however do not expect much difference if you sprinkle it on the amp
12-17-2008, 11:03 PM
#24
Here's the Richard clark test (summary actually) for everyone's convenience:
Richard Clark Amplifier Challenge FAQ
Richard Clark Amplifier Challenge FAQ
12-18-2008, 12:02 AM
#26
Here's the Richard clark test (summary actually) for everyone's convenience:
Richard Clark Amplifier Challenge FAQ
Richard Clark Amplifier Challenge FAQ
12-18-2008, 09:13 AM
#27
50 Watt CAFz'r
Join Date: Jun 2008
Posts: 138
Sasha this is what the amp challenge is about.
quote,
"guys--it always circles back to the same old thing--i have never said or even inferred that there is no meaningful difference in amps--of course there are differences--some amps cost more because they are built better--perhaps they will last longer--or play longer without overheating--or have better resale value because they have more "brand appeal" or do more because they have more features--all I ever said was that WHEN THEY ARE COMPARED EVENLY THE SONIC DIFFERENCES BETWEEN AMPLIFIERS IS BELOW THE AUDIBLE THRESHOLD OF HUMAN HEARING-- as for what we actually hear consider that if we compare two identical amps but turn the bass boost up on one and leave the other flat we will be able to hear the difference between two identical amps that have consecutive serial numbers--read my challenge rules--it should make sense"
Richard clark
quote,
"guys--it always circles back to the same old thing--i have never said or even inferred that there is no meaningful difference in amps--of course there are differences--some amps cost more because they are built better--perhaps they will last longer--or play longer without overheating--or have better resale value because they have more "brand appeal" or do more because they have more features--all I ever said was that WHEN THEY ARE COMPARED EVENLY THE SONIC DIFFERENCES BETWEEN AMPLIFIERS IS BELOW THE AUDIBLE THRESHOLD OF HUMAN HEARING-- as for what we actually hear consider that if we compare two identical amps but turn the bass boost up on one and leave the other flat we will be able to hear the difference between two identical amps that have consecutive serial numbers--read my challenge rules--it should make sense"
Richard clark
12-18-2008, 10:37 AM
#28
50 Watt CAFz'r
Join Date: Oct 2008
Posts: 133
When it comes to sound, more expensive, better topology, better on the paper, means absolutely NOTHING when the music starts to flow.
I'd give you an example, for those who'd any experience in OP Amps. Take a look at the spec of TI OPA627, vs AD 8160. In some aspects, the AD8160 is better than the OPA627. Listen to how an amp built with OPA627 and AD8160 and you'd notice immediately that, specs, and numbers, mean nothing because sound signature dictates whether one find it sounds good or not.
Take a look at the Grado RA-1 headphone amp for example, tons of people swear by it. Any idea what it's made of and what kind of topology it uses? the most basic POS topology in amplifier circuit 101.
I just find it funny that people think paying more would actually mean getting better stuff. Not to say that more expensive stuff aren't necessarily better, but they are not necessarily as good as you expected. OTOH, cheaper stuff aren't necessarily worse than more expensive ones.
I'd give you an example, for those who'd any experience in OP Amps. Take a look at the spec of TI OPA627, vs AD 8160. In some aspects, the AD8160 is better than the OPA627. Listen to how an amp built with OPA627 and AD8160 and you'd notice immediately that, specs, and numbers, mean nothing because sound signature dictates whether one find it sounds good or not.
Take a look at the Grado RA-1 headphone amp for example, tons of people swear by it. Any idea what it's made of and what kind of topology it uses? the most basic POS topology in amplifier circuit 101.
I just find it funny that people think paying more would actually mean getting better stuff. Not to say that more expensive stuff aren't necessarily better, but they are not necessarily as good as you expected. OTOH, cheaper stuff aren't necessarily worse than more expensive ones.
12-18-2008, 07:20 PM
#29
I disagree that it is pointless but will agree that it offers little insight. I will keep this really short(yeah right) as no one is ever convinced by anything.
Damping is mostly a factor of the driver itself and all the component in the chain (connections, xovers, wires, enclosure, frequency), the amp damping spec is really only a marketering term. Proof of it is most specs don't even say at what frequency it was measure at making it even less relevant. But there is lots of good info on the net here is a good one with math that explains why it is irrelevant. I would also like to point out that high amplifier damping is a source of concern for some "audiophiles" as it may indicate another distortion inducing behaviour. DP is a useless spec to look at in my mind.
Damping Factor: Effects On System Response — Reviews and News from Audioholics
The scientific method of testing is really important and is why an EQ is needed to be used when doing blind tests. Why? We know for certain that a few things will change the sound and that is :
-Volume
-EQ
They are both essentially the same and we use them eveyday to affect the sound. Knowing this when tesing an amp we would need to make sure that those are not a factor thus why we match gains (ensure that amps are the same volume) and EQ out the built in EQ in the amp. MAke no mistake about it, a bass know or treble **** even at zero is not truely zero. Once that is removed, then you can try and focus on other aspects of the amp, but so far that has always been very sufficient to make amps indistinguishable when using the human ear wich in itself is a crude measureing device. Then if the ear can't hear a difference in such a scenario then it is futile to start isolating components even further as the 2 sample amps in comparisons would presumbly not have all the same components in the first place.
This leads one to think that if all it takes is an EQ to make the amps indistinguishable to the ear (not to measuring instruments though) then one would asusme that using better components are for purpouses such as :reliability, marketing and because people ask for it because they assume it must be better.
Hearing is far from a reliable tool as to many things can affect ones perceptions. Mood, expectactions and frame of mind are some of the things that can affect how we hear things. There are many examples of the brain acting on what we hear and this is why we can see in double blind test people distinguish differences in sound when the same amp is used in both scenarios. Another example :when you are paying attention to something and you stop noticing the sound of traffic in the background. The brain can manipulate what you hear and how you hear it. It can and it does. There is a field dedicated to this type of thing.
Unscientific method is used far to often since a lot of comparisons between components are often done with systems that have different gains, components, environments, expectations, time of day, enclosures, path lenght differences aiming ect and people will still venture out without any type of realistic testing methodologie to identify what the diference in a specific sound is: "well I have heard these speakes many times before and know what they can do, but in my new install the CD player is holding them back in SQ"..."I know what I hear". This is so frequent and people convince themselves that it is relevant when in fact it obviously isn't. The sound can be different for many reasons but there is no way to pinpoint only one component in such a way. Not to mention that memory is extremely unreliable for remembering sounds like this, think about the posts or conversations about people saying that their own unchanged system sounds different at night. If the same system can sound different to a person depending on the time of day how can one be trusted to rember and identify subtle differences and attribute it to a DAC or a preamp or a specific component in the amps: oh those t03 are awesome sounding!
Here is a great example, just look at the pool results.
Does music sound better at night? - DIY Mobile Audio - Technical, Advanced & Informative
Alright rant over.
Damping is mostly a factor of the driver itself and all the component in the chain (connections, xovers, wires, enclosure, frequency), the amp damping spec is really only a marketering term. Proof of it is most specs don't even say at what frequency it was measure at making it even less relevant. But there is lots of good info on the net here is a good one with math that explains why it is irrelevant. I would also like to point out that high amplifier damping is a source of concern for some "audiophiles" as it may indicate another distortion inducing behaviour. DP is a useless spec to look at in my mind.
Damping Factor: Effects On System Response — Reviews and News from Audioholics
The scientific method of testing is really important and is why an EQ is needed to be used when doing blind tests. Why? We know for certain that a few things will change the sound and that is :
-Volume
-EQ
They are both essentially the same and we use them eveyday to affect the sound. Knowing this when tesing an amp we would need to make sure that those are not a factor thus why we match gains (ensure that amps are the same volume) and EQ out the built in EQ in the amp. MAke no mistake about it, a bass know or treble **** even at zero is not truely zero. Once that is removed, then you can try and focus on other aspects of the amp, but so far that has always been very sufficient to make amps indistinguishable when using the human ear wich in itself is a crude measureing device. Then if the ear can't hear a difference in such a scenario then it is futile to start isolating components even further as the 2 sample amps in comparisons would presumbly not have all the same components in the first place.
This leads one to think that if all it takes is an EQ to make the amps indistinguishable to the ear (not to measuring instruments though) then one would asusme that using better components are for purpouses such as :reliability, marketing and because people ask for it because they assume it must be better.
Hearing is far from a reliable tool as to many things can affect ones perceptions. Mood, expectactions and frame of mind are some of the things that can affect how we hear things. There are many examples of the brain acting on what we hear and this is why we can see in double blind test people distinguish differences in sound when the same amp is used in both scenarios. Another example :when you are paying attention to something and you stop noticing the sound of traffic in the background. The brain can manipulate what you hear and how you hear it. It can and it does. There is a field dedicated to this type of thing.
Unscientific method is used far to often since a lot of comparisons between components are often done with systems that have different gains, components, environments, expectations, time of day, enclosures, path lenght differences aiming ect and people will still venture out without any type of realistic testing methodologie to identify what the diference in a specific sound is: "well I have heard these speakes many times before and know what they can do, but in my new install the CD player is holding them back in SQ"..."I know what I hear". This is so frequent and people convince themselves that it is relevant when in fact it obviously isn't. The sound can be different for many reasons but there is no way to pinpoint only one component in such a way. Not to mention that memory is extremely unreliable for remembering sounds like this, think about the posts or conversations about people saying that their own unchanged system sounds different at night. If the same system can sound different to a person depending on the time of day how can one be trusted to rember and identify subtle differences and attribute it to a DAC or a preamp or a specific component in the amps: oh those t03 are awesome sounding!
Here is a great example, just look at the pool results.
Does music sound better at night? - DIY Mobile Audio - Technical, Advanced & Informative
Alright rant over.
12-18-2008, 10:15 PM
#30
50 Watt CAFz'r
Join Date: Jun 2008
Posts: 138
^^well put! and by the way Sasha, I've only been listening to music for 40 years now...as a professional musician and audio engineer...so I have some idea of what it should sound like, and i have my hearing tested annually...still 20hz to 16 khz @ +/- 5dbs, 16khz-18khz @-10dbs.
