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DVD player for CD playback - audio levels.

Discussion in 'audio' started by springer, Aug 14, 2019.

  1. Nagraboy

    Nagraboy How’d all these people get in my room?

    I had an old NAD amp like that. Think it was a C320BEE. Had to use 26dB of attenuation (via Russ Andrews plugs) and it was still less than 9 o’ clock on the volume control for normal listening levels. What are these designers thinking of? Just crazy.
     
  2. John Phillips

    John Phillips pfm Member

    It's more an industry problem than a designer problem. It's mainly due to there being only informal signal level "standards" for non-professional audio gear, and reaction to changes in technology:
    • I think the Rotel RA-312 (from no later than 1981) has a 150 mV line level sensitivity for full output. It's very sensitive and typical of a time when independently designed pre-CD sources such as tuners would produce not much more than about that.
    • Then from 1981 onwards CD changed all that with a much larger output voltage to keep its greater dynamic range above the noise floor.
    There was also a difference in informal signal level standards then between UK and USA. Pre-CD, a separate power amplifier from USA often had a 2V sensitivity (maybe still?). While a typical UK power amplifier might have had about 0.5 V sensitivity. Typical US and UK pre-amplifiers had correspondingly more / less gain. Mix and match at your peril.

    Even now, designers of amplifiers don't know for sure how much level they will get from sources. So they seem to err on the side of providing too much gain. So level controls often operate too close to the bottom of their range. However, providing too little gain would probably be more of a disaster.

    In this case a 20 dB in-line attenuator would probably be required to make the volume control situation comfortable. Good practice is to insert the attenuator at the destination end of the interconnect, not at the source end.
     
    ToTo Man likes this.
  3. ToTo Man

    ToTo Man the band not the dog

    As @John Phillips explains, high input sensitivities are generally par for the course with vintage gear as source outputs were typically much weaker back then, however it would surprise you how much the problem persists in contemporary gear. I suspect this is due to interference from the marketing team who are worried that their amp might be perceived by consumers as 'underpowered' compared to the competition if it doesn't get to ear-bleeding volumes with just a small rotation of the volume knob. Rather like the "loudness wars" in some respects. A very depressing reality that smoke & mirror "willy-waving" often takes precedence over genuine usability and performance.
     
    TonyScarlett likes this.

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