Agdr posted this:
ODA works perfectly with HE500 and HE6 up to 118dB and 113dB
So here is your answer about the HE500 and HE6. The ODA will not only power both perfectly with the standard +/-12.5Vdc power rails, they will do so all the way up to 118dB and 113dB, respectively. And those were just the power levels that broke the spreadsheet. Nobody should be listening to headphones at those levels anyway! See the hearing damage chart at the bottom of the fellow's spreadsheet.
I have created a new folder at the V2.0 ODA Google Drive link called "Headphones vs. the ODA". Here is a direct link to it:
In there I have used a nice power calculation spreadsheet that was posted on Head-Fi back in December. See the README file in that folder. It has a link to that post with the sheet, and links to the specification pages for the HE500 and HE6.
For more normal levels I have also included sheets for both at 95dB.
Note that only the 113dB power level with the HE6 is coming near the using the full 7.25V(rms) swing of the ODA with the +/-12.5Vdc rails, at 6.67V(rms). The current is still a no-brainer for the ODA, divided by 6 for the 6 output chips with 70mA available each for powering the load.
So.. these kind of headphones are exactly what the ODA eats for lunch.
Also note that the +/-15Vdc power rails should not be used with either headphone. +/-12.5Vdc does the job as per the charts, and the output chips could overheat at the higher voltages. Those are only for 300R and 600R cans.
--> I'm going to post this PM contents in the thread becasue it is an excellent question and really shows what the ODA is useful for. More good work, Alex! Thanks.