hi im interested to know why the average cd player output is 2v rms- and what affect this has on low input 1970s 80s amps- nad 2030 for example
It depends if the input of your amp has a gain stage before the volume control. If so a voltage devider could solve the problem. Not the most elegant but sufficiant. If there is no gain stage then you just lower the volume setting. Also not elegant as it limits the range of control. So also here a devider on the cd input can resolve this.
The Sony/Philips "redbook" spec for the CD medium, originally issued around 1980, specified a maximum output for cd players of 2 volts for unbalanced outputs. This figure is higher than had been the case for analog sources.
An unattenuated CD player can cause a 'brightness' in the sound due to the saturation of the amplifier input stages when the input exceeds a certain level.
The solution is, of course, to use an attenuator (L pad) at the amplifier input.
An unattenuated CD player can cause a 'brightness' in the sound due to the saturation of the amplifier input stages when the input exceeds a certain level.
The solution is, of course, to use an attenuator (L pad) at the amplifier input.
It's something of a de-facto standard not dictated in any rulebook to my knowledge (I could be mistaken here), just adhered to by most vendors whose gear feature solid-state output circuits. You can notice that tube based output stages are often something other than @2RMS@FS. My guess is that 2 Volts was settled on because it's a convenient amplitude for players that feature op-amp based analog stages. The most common type. Most line-level preamp inputs are able to accept 2VRMS input signals without problem, the volume control providing sufficient attenuation to prevent overdrive. So, long as there is no amplification taking place prior to the volume attenuator, as was mentioned above.
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