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?

  • 4
    \$\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

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.

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.