DITHERED DIGITAL VOLUME CONTROL
A digital volume control, implemented in software, can actually be superior to analogue
attenuators. Among other things, it never wears out, as a mechanical control
eventually does, and the left/right channel tracking, as well as linearity, is
excellent. It also helps eliminate extra components in the sensitive analog portion of the signal path.
It can also provide a number of features simply not possible with analog
controls. We use a sub-Nyquist noise-dithered algorithm to deliver 0.5 dB
attenuation steps from 0 to -20 dB, accurate to 0.05 dB, and 1.0 db steps from -20 dB to -72 dB.
The Audiophilleo1 tells the computer that it supports
internal attenuation, causing the
computer to simply tell the Audiophilleo what attenuation level to use.
The computer itself does not do actual system level attenuation with the
Audiophilleo1. Of course you can still attenuate in your media player
When using the Audiophilleo1, you have two choices for volume control:
- A preamplifier or DAC with a high-quality analogue or digital volume control can
be used. In this case you tell the Audiophilleo to not respond to volume
changes, "locking" the Audiophilleo volume at any value. This
allows for a hybrid approach where some fixed digital attenuation is done in
addition to variable analog attenuation.
- By default, the Audiophilleo volume control is un-locked. In this case your remote control's volume buttons
will change the computer's volume which will in turn send the volume level to
the Audiophilleo1 for attenuation. The computer or joystick can also be
used to change the volume.
The following features are included with the Audiophilleo1 volume control:
- An infrared remote control can be used to tell the Audiophilleo to change the volume. The Audiophilleo menu system can be used to learn to respond to any remote you have.
The joystick can also change the volume.
- The volume can be locked so that neither the joystick nor remote control nor computer can change the volume. Any attempt to change the volume is simply ignored.
- The maximum allowed volume can be set. Any attempt to set the volume above this maximum is ignored. This can help protect your speakers from accidental volume changes.
- "Pro" mode can be enabled. This causes the Audiophilleo to ignore the computer's requested volume level. The Audiophilleo
does not send volume commands to the computer and sets the volume level only internally. This allows for more accurate dB steps to be used since the computer no longer decides the step size.
- The volume can be muted. The mute and un-mute transitions are smooth in order to eliminate pop noises.
- The L/R balance can be set, causing the relative attenuation of the channels to be offset.
- Polarity reversal.
- Mono mode. This causes the L/R channels to be mixed into a monaural stereo stream.
For more information on how good dithered volume controls can be, see
Dither Explained or read more on our Articles page.