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Headphone OPAMP recomendation for battery usage.

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Ok, here is the blast.  I have a worst case dual rail +7.5v and -7.5v battery supply.
I need to add gain from a stereo line out of ~6db, or 2x, an input load of ~1k or 600ohm will do.
I want a clean audio output at ~7vp-p (+/-3.5v), ~2.5v-rms driving >250ma load without distortion.

Ok, I know how to use op-amps in analog circuits.  I'm looking for a recommendation of the magic op-amp which will be crystal clear and not kill my batteries with too much background load.  I also don't want any phase errors in the upper 10khz-20khz as well as any cross-over distortion whatsoever.

Is that 250 mA load at 2.5 V rms correct?
That would be a 10\$\Omega\$ load impedance, which is typical of a loudspeaker.

The NE5532 (dual) can drive a 600\$\Omega\$ load (more typical of a headphone) easily, and pulls typical 7 mA (quiescent) at +/- 7.5 V power;  I believe that is for the two-channel device.
Actual output current into a short circuit load is specified (at +/- 15 V) as typ. 65 mA (not specified at lower voltage).
Any op amp will pull at least the output current from one or the other supply rail:  250 mA is rather high for battery power.

"None whatsoever" is not a specification:  it is a pious wish.
The usual methods to reduce crossover distortion increase the quiescent current draw, which is a reasonable tradeoff for audio applications, but problematic for low-power battery operation.
What level of distortion and phase error is your specification?

3.5v / 16ohm = ~220ma

Yes, I have low impedance earphones and I want my ears to burn without distortion.

For 32 ohm headphones, I would still need a 110ma capable opamp.

I would love ~0.01% distortion at full power, full bandwidth.  However, for full power, I could tolerate 0.1% so long as 75% power delivers 0.025%.

Awww, the OPA2677 was so damn close.  It's limiting factor was the power supply of +/-6v.  If it went to 7.5 through 9v, it would meet all my criteria on top of supporting 500ma.

The Richtek RT9146/7 might do it.  However, who is Richtek?  Never heard of them.  Can they be trusted?


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