anyone know the RMS output of an ipod?

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My Nano appears to regulate the internal 3.6 V Li Ion battery to 3.0 V

so it can put out a little over 1 Vrms sine

1st Gen Shuffle's are interesting lab toys since they are DC coupeld - fractional Hz waveforms, multi second ramps are possible

as for forums - this is the Digital Source Forum - hard to be more relevant to USB/flash DAC
 
zigzagflux said:
Airport Express is 1.5V rms at 0dB, and I believe the analog output is identical to the iPod.


Airport Express uses TI's PCM2702 or similar, the iPods differ from model to model.
Airport Express then has just a regular output filter directly connected to the (USB-) DACs output. iPods differ, yet again.
On top of that, the analogue part in Airport Express is powered with 5V (with the digital part supplied with 3.3V), iPods manage their battery power to something much lower, as jcx mentioned.

@Gain: Which iPod do you want to connect? I could try measuring one for you. Please indicate a load, i.e. input impedance of the circuit you want to drive.

PS: The current Shuffles are interesting, too. Multi-Megaherz rubbish on the output, the complete opposite of what you would expect! :D
 
sek said:



@Gain: Which iPod do you want to connect? I could try measuring one for you. Please indicate a load, i.e. input impedance of the circuit you want to drive.


standard RCA line level jack. basically i want to know what the RMS (or peak) value of voltage the device puts out when plugged into a "stereo" input. in this way, i will be able to tell if im feeding my stereo with too much or too little line drive.

input impedance 20K-100K? Whatever RCA inputs are.

thanks for the many great replies.
 
i suspect is somewhere in the ballbark of line level (~ +/- 1VRMS) since i have the ipod hooked to a line level input on a receiver im listening to now, ipod cranked to about 4/5, stereo on about 4, and it sounds (subjectively, to me) to be about the same input level as cd or tv or tape player would put in.




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All recent iPods have been video capable and all but the earliest models have a touch wheel on the front. :)

Each iPod has it's model number engraved on the lower right of it's back side.

Choose between iPod Classic (introduced September 2007), iPod with Video (late 2006 model) (discontinued September 2007) and iPod with Video (2005 model) (discontinued September 2006).

In case you can't find out, I'll just measure an iPod Classic this evening. ;)
 
see attached. thanks again for your help.
 

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ok just hooked up a stereo dual ganged pot to my tape input on the line level side. (i have lots of different sources that seem to all have there unique version of what 'line level' means) so this comes in handy. i can just set the pot for the correct amount of input drive for whatever i had connected.

now onto the ipod. i had just finishing calibrating the pot so that a cd player sounded about right for line level. didn't sound weak at all yet could crank to ten with no distortion. so i hook up the ipod without moving the pot. had to crank it up (the ipod) all the way just to get about 1/2 the sound the signal level from the cd player gave.

so i guess that ipod puts out somewhere 1/2 line level (ie: ~500mv RMS)

still hoping someone out there has a scope that can confirm.
 
Turns out the level via iPod Classic's headphone out into a high impedance load is Up ≈ 0.47 Vp (peak) with my European model (probably output level limited due to EU regulations).

This means Urms ≈ 0.332 Vrms and thus Lu ≈ -7.3 dBu.
 

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The level via Apple's iPod Dock's line out into a high impedance load is Up ≈ 1.14 Vp (peak) with the Dock powered by the iPod (similar, but not identical to a direct out condition).

This means Urms ≈ 0.8 Vrms and thus Lu ≈ -0.3 dBu.
 

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