Power question

[Coyote-X]

Hi, I've got two amps, a JVC RX-7010V rated at 100wpc from 2002 and a Sony TA-AX335 rated at 155w total for two channels... from... Well honestly I haven't found any info on it, but my friend's dad has had one ever since he can remember so I'm betting it's almost as old as I am. I'm driving a set of Infinity Entra One bookshelf speakers that were bought with the JVC, rated 15-125 watts RMS.

When I can turn the JVC up to around 70/80 volume level before it starts to hurt my ears, while with the Sony I can manage about half, depending on the music, before it does the same. Lacking any equipment to actually tell how much power they're both putting out at those volume levels, can anybody tell me if this is because the Sony is distorting sooner than the JVC? Or could it actually putting out more power at a lower volume setting, despite being rated for less?

I'm somewhat confused as to which one I should use - the JVC because it can go 'louder' on the dial, or the Sony, and just be careful with the levels? Not being experienced, I am having a hard time telling whether it's just distorting or whether it's actually louder. Could it be that the decibel level on the JVC is actually higher but it just doesn't 'sound' as loud because it's still outputting clearly?

[kexodusc]

When I can turn the JVC up to around 70/80 volume level before it starts to hurt my ears, while with the Sony I can manage about half, depending on the music, before it does the same. Lacking any equipment to actually tell how much power they're both putting out at those volume levels, can anybody tell me if this is because the Sony is distorting sooner than the JVC? Or could it actually putting out more power at a lower volume setting, despite being rated for less?

If the amp can actually get louder without noticeable distortion, it has more useable power. I'm guessing the Sony runs out of room at 1/2, lots of amps do this. The indication on the volume knobs is not a useful comparison. They're very arbitrary in determing the reference level for dB's. (it's not actually dB's because they couldn't predict how loud the amp would play with every possible speaker).


I'm somewhat confused as to which one I should use - the JVC because it can go 'louder' on the dial, or the Sony, and just be careful with the levels? Not being experienced, I am having a hard time telling whether it's just distorting or whether it's actually louder. Could it be that the decibel level on the JVC is actually higher but it just doesn't 'sound' as loud because it's still outputting clearly?
Use whichever one sounds better at the listening volumes you most often enjoy. Being louder doesn't mean better, and distortion isn't really a problem in most amplifiers until they're pushed to the limit. You should be able to tell very easily if distortion is ruining the sound.
Trust your ears.

[hermanv]

There is no relationship between dial posistion and watts. Yes, turning it higher makes the output louder but that's only valid for one input level.

If you don't move the dial, but double the input signal level you end up with 4 times the watts at the same exact knob setting.

The knob should be labled "Gain" not "Volume" Since there is no standard gain for amplifiers, many acheive full output at totally different knob settings. Ignore the knob, use the amp that sounds best to you.

[Edit] Note; that all else being equal, the amp with the most distortion will sound louder for the same output power.

[Coyote-X]

Thanks for the good info. I wasn't really aware that's how the volume settings worked (thought they were proportional to the total power the amp could put out). After listening to both off and on last night, I think I'm going to stick the JVC 'cause it's overall cleaner and I like the digital optical inputs on it. Kind of suspicious of the Sony anyway, 'cause it got very hot to the touch after extended playing.