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<blockquote data-quote="helotaxi" data-source="post: 2587554" data-attributes="member: 550915"><p>The amps I have seen a legit spec for the input voltage range on specify the load into which the range is valid. As with all amps specs, input voltage range should be taken with a grain of salt because without supporting numbers to go along with it, it really means nothing.</p><p></p><p>Matching levels is still what you're doing. You are matching the input level of the amp to the output at that impedance. I think that your misunderstanding comes from trying to apply theory to reality without accounting for the losses that separate the two. In a perfect world you would set the gain based solely on the voltage range markings on the input sensitivity control and that would be that regardless of the load that the amp was driving. You would also be able to get twice the power by halfing the load on every amp. We know the latter isn't the case so why should we expect the former. The amp simply isn't that smart, most are quite dumb in fact. They take an input signal and try to multiply it by a certain factor and you have to tell it the desired factor. Even if it has no prayer of pulling it off it will still try.</p><p></p><p>As I said above, an amp that is rated to double its output every time the load is halved, is underrated at the higher impedances. If you set the gain on one of those amps with a 4 ohm load to give you rated power, the setting should be pretty close all the way down to the lowest rated impedance of the amp. Most amps aren't rated that way though. They are rated with the higher high impedance power that they had to make in order to make their low impedance power. They are not more or less sensitive at any given impedance they are simply not rated on any kind of scale. Take our example from before that doubles powr as the load drops and set it to produce not rated, but maximum power at the higher impedance. You will discover two things: 1)it makes a lot more than rated power and 2)if you tried to run it into a lower impedance load without resetting the gain you will probably clip the hell out of it. Since a low 4 ohm rated power is no longer advantageous in competition, amp makers rate their amps with the actual power it can produce rather than way underrating them at 4 ohms so they will make their low impedance rating when the higher current on the output starts to sag the voltage rails.</p><p></p><p>Honestly the perfect analog amp would have a button on the end. You would use that button to set the amp up once and then you wouldn't have to worry about it. The way the button would work is that you would turn the source volume all the way down and press the button to mark the zero point. Then you would turn the source volume all the way up and press the button again setting the max position. The preamp would then be smart enough to set its own gain based on that range giving you full unclipped power at max volume and silence at min volume and the full range in between. The other option would be a standard digital signal and data bus protocol that would leave the signal digital until the amp and make gain setting a thing of the past all together.</p></blockquote><p></p>
[QUOTE="helotaxi, post: 2587554, member: 550915"] The amps I have seen a legit spec for the input voltage range on specify the load into which the range is valid. As with all amps specs, input voltage range should be taken with a grain of salt because without supporting numbers to go along with it, it really means nothing. Matching levels is still what you're doing. You are matching the input level of the amp to the output at that impedance. I think that your misunderstanding comes from trying to apply theory to reality without accounting for the losses that separate the two. In a perfect world you would set the gain based solely on the voltage range markings on the input sensitivity control and that would be that regardless of the load that the amp was driving. You would also be able to get twice the power by halfing the load on every amp. We know the latter isn't the case so why should we expect the former. The amp simply isn't that smart, most are quite dumb in fact. They take an input signal and try to multiply it by a certain factor and you have to tell it the desired factor. Even if it has no prayer of pulling it off it will still try. As I said above, an amp that is rated to double its output every time the load is halved, is underrated at the higher impedances. If you set the gain on one of those amps with a 4 ohm load to give you rated power, the setting should be pretty close all the way down to the lowest rated impedance of the amp. Most amps aren't rated that way though. They are rated with the higher high impedance power that they had to make in order to make their low impedance power. They are not more or less sensitive at any given impedance they are simply not rated on any kind of scale. Take our example from before that doubles powr as the load drops and set it to produce not rated, but maximum power at the higher impedance. You will discover two things: 1)it makes a lot more than rated power and 2)if you tried to run it into a lower impedance load without resetting the gain you will probably clip the hell out of it. Since a low 4 ohm rated power is no longer advantageous in competition, amp makers rate their amps with the actual power it can produce rather than way underrating them at 4 ohms so they will make their low impedance rating when the higher current on the output starts to sag the voltage rails. Honestly the perfect analog amp would have a button on the end. You would use that button to set the amp up once and then you wouldn't have to worry about it. The way the button would work is that you would turn the source volume all the way down and press the button to mark the zero point. Then you would turn the source volume all the way up and press the button again setting the max position. The preamp would then be smart enough to set its own gain based on that range giving you full unclipped power at max volume and silence at min volume and the full range in between. The other option would be a standard digital signal and data bus protocol that would leave the signal digital until the amp and make gain setting a thing of the past all together. [/QUOTE]
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