I'm slowly getting my Buffalo-IIIPro setups going. Out of an over-abundance of caution, I powered up the IVY that I'm using as my initial active I/V (a Legato comes later) on the ES9028 setup off the DAC board and measured the input and output voltages... all near zero, so I felt ok putting it on the DAC and it is working ok (AND sounding pretty darned good!).

When I did the same with the Mercury for the ES9038 setup, I saw 0V on the outputs, but near or at the 15V rail voltage on the +- input pins. My questions:

1. IS that what I should expect to see with no input? I could see this being the result of the servos not having a valid input and locking up to rail voltage.

2. OR is it an indication of something I did wrong assembling and installing it? I checked and double and triple-checked my power connections before power-up and they measure ok powered on.

3. OR does it require a valid input connection at power-up and I may have just trashed it?

At this point, I'm not willing to plug it into the DAC board and power it up given what I saw. I've already confirmed the ES9038 board is working ok using a transformer output stage I stole from a developmental RPi ES9028Q2M-based board... I can go back to that to continue my incremental checks of the systems AND also focus on the ES9028 setup while I wait for an answer.

So please let me know if I did something wrong setting it up, ruined it by powering it up with no input, or that is what I should expect to seen and I should just plug it in and power it up.

TIA!

Greg in Mississippi

Answered in the DIYAudio Mercury thread... DAC running and sounding great! THANKS BRIAN for the answer & Brian & Russ for the designs!

Greg in Mississippi