The HA-1 uses a pure analogue audio path after its DAC. The volume is adjusted by rotating a potentiometer by hand or by motor via the remote control. The numeric volume display is created by taking samples of a voltage divided by the potentiometer. The numeric dB value displayed on the screen is based on the measurement of the volume knob position. It indicates the approximate gain or attenuation level of the pre-amplifier output relative to the input signal. It is normal for the display value to vary a few dB when the volume knob moves in the very low range due to the logarithmic nature of the volume control curve.

 

When using the remote control to reach a certain numeric dB value, the following should be taken into consideration:

 

1. The time it takes to measure the potentiometer position and average multiple measurements to get a reliable reading. 

2. The human reaction time from seeing the desired dB value onscreen to releasing the remote control button. 

3. The "de-bounding" time for processing the "button up" event, so that the HA-1 knows the button is indeed released and it is not a signal interference or button contact glitch.   These three events occur while the knob is still rotating. As a result, when you are using the remote control to adjust the volume level and you see the desired dB value on the screen and release the button on the remote control, the knob will overshoot a bit.   If you need to turn the volume knob to a very specific numeric dB value, we recommend turning the knob by hand slowly or pressing the remote volume      buttons in repeated single clicks. Pressing and holding the volume button on the remote control serves as a convenience feature for rotating the volume knob rapidly, and it is not designed to precisely reach a certain dB value.   Ultimately, if you are accustomed to digital volume controls that can be rapidly dialed in to a certain dB value, the analogue volume control on the HA-1 may take some getting used to.  However, once you become familiar with it, you will appreciate its very fine volume adjustment, fluid movement, and great sound.