OPPO recommends waiting at least 30 seconds between On-Off cycles to avoid damage to the circuitry. You can buy a switching box for comparing up to 4 headphones with one amp/dac. You just have to determine the SPL settings on the volume pot for each headphone for equal sound level matching. Alternatively, you can hook up the switch box in reverse to compare up to 4 amps/dacs with one set of headphones.
7/27/14 at 4:10pm