[Elecraft] Windows 10 Bug

[TJ Campie]

Joe,
You are correct when the input device has been enumerated as a microphone input, which is the bug. Without "clearing" the bug forcing windows to enumerate it as a line in device, 100 on the slider is indeed adding gain. 

However after clearing the bug, it's now enumerated as a line in device and 100 on the slider is 0db, even if it reads +30 (the UI and dialogue box still thinks this is a microphone input device, this is part of the bug). This was verified by feeding a reference signal of a known level into the chip and obtaining a known output level, confirming 100 on the slider is indeed 0db of gain/attenuation AFTER clearing the bug. 

This behaviour is confirmed by TI themselves in this whitepaper: http://www.ti.com/lit/an/sbfa020/sbfa020.pdf 

If you have a signal generator I highly recommend feeding a reference level signal into a device using the chip and measuring the output yourself AFTER clearing the bug. Remember, you are correct that the slider value will add gain when it's been incorrectly enumerated as a microphone device. Measure a reference input signal AFTER clearing it. Hope that helps the confusion

73
TJ W0EA