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What is typical audio signal voltage range on Line out connector of consumer electronic devices? (Vmin/Vmax) I need specify Input voltage range to calculate op-amp. Vin pk-pk, Vin Midpoint, or Vin Min, Vin Max I know the line level depends on the device type, but in general?

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    \$\begingroup\$ Unable to google? Line Level -- Wiki. If you already read it, then you should have expanded your question. \$\endgroup\$ – jonk Apr 30 '18 at 19:04
  • \$\begingroup\$ +1 for @jonk ....but many consumer products actually have a headphone out jack, which is not quite the same ....here you may find 1-100 mW or more into 32-600 Ohms. \$\endgroup\$ – Jack Creasey Apr 30 '18 at 19:17
  • \$\begingroup\$ @JackCreasey Output power for headphones varies a bit from device to device. I remember seeing a table with commonly owned cell phones, for example. But delivered into the usual \$32\:\Omega\$ headphone, it's typically around \$4-5\:\text{mW}\$ if I can trust the few sources I read. This suggests a peak of about \$500\:\text{mV}\$, to me. Obviously, there are different amplifiers with different target headphone impedances, too. So one has to decide the target source, I suppose, if considering headphone jacks as opposed to line out connectors. \$\endgroup\$ – jonk Apr 30 '18 at 19:27
  • \$\begingroup\$ Not for headphone out, I'm talking only about Line out voltage. What is Vin Midpointvoltage? \$\endgroup\$ – electro-tec Apr 30 '18 at 19:36
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Usually consumer line outputs are nominal -10dBV (about .316V RMS).

But many devices put out less than this, for example a Mac Pro 5,1 line out puts out about 180mV RMS (250mVp) with a sinusoidal input of -20dBFS and maxes out at about 2V RMS (2.8Vp) with an input of 0dBFS. These are open-circuit measurements I have taken myself.

So to be safe you should design for -10dBV nominal (max headroom would be 20dB above that so +10dBV [3.16V RMS]). That way most consumer devices won't clip your input.

But you should also choose a device you think might be used with your design frequently and measure it so you know for sure what you are expecting. Like a headphone jack on an iphone or something.

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