Rockbox mail archive
Subject: Digital I/O faq entry revised
From: Andreas Stemmer (groovingandi_at_gmx.de)
I just revised the digital i/o faq entry and added the suggestions of
Martin Borus and Michael O'Quinn. Sorry for the delay.
Thank you everybody for the comments! Sometimes, it's a little bit
difficult to know what sounds good and what doesn't if English isn't the
Can one of the developers (Daniel perhaps?) replace the existing version
with the new one pleeeeaaaase?
(If there are no complaints of course)
74. What should I know about the digital I/O connector on my jukebox?
The Recorder models have a connector for digital audio output using the
common S/PDIF standard (Sony/Phillips Digital Interface). This jack is
not present on the Studio/Player/FM Recorder models. By using the
digital output in combination with high class external equipment, you
can get much better sound quality out of your jukebox. This is because
you can use better DA-converters and better amplifiers, plus you
eliminate the analog audio connections between the jukebox and your
equipment that can introduce noise and distortion.
The Recorder and the FM Recorder models are able to record from digital
sources, too. The digital inputs don't have the 15kHz lowpass filter
like the analog inputs and you are sure to minimize the noise floor.
Although S/PDIF can be an electrical or an optical signal and there are
many devices that support both, the socket on the jukebox is for
electrical signals only! Some devices have sockets that look the same,
and can take either an optical or an electrical cable, but sadly this is
not true with the Jukebox.
If you want to connect your amp with digital input (RCA type) to the
output of your Recorder you need an adapter cable (3.5mm stereo jack to
dual RCA jack). Plug the 3.5mm stero jack into the digital I/O socket of
your jukebox and the red RCA jack (right channel) into the digital input
socket of your amp and that's it. You don't have to enable the digital
output, since it's always on. The sound settings on the digital output
are always flat, your volume, bass, treble, bass boost, loudness
settings won't have any effect here, that's why fade in/out won't work,
either. The sampling frequency of the digital output is the same as the
sampling frequency of the mp3. It's therefore possible that your
external equipment won't be able to synchronize to the output of your
jukebox if you have mp3's with sampling frequencies other than 32, 44.1
or 48kHz (The pitch shift function also modifies the sampling
For recording digital signals on the Recorder, use the white RCA jack
(left channel) and plug it into the digital output of your CD player, MD
player or whatever. Don't forget to select digital input in the
recording settings! Note that there exist some adapter cables with
different color coding, so if output doesn't work the red jack try the
white RCA jack, too. The tip of the 3.5mm jack is the digital input, the
ring is the ouput.
For recording digital signals on the FM Recorder, you need a special
4-pole 3.5mm plug (shaft = ground, tip = left channel analog line in,
first ring (next to tip) = right channel analog line in, second ring =
If you want to connect devices with optical inputs/outputs, you need a
small converter box which converts your signal from electrical to
optical (for digital output from the Archos) or optical to electrical
(for digital recording in to the Archos).
Page was last modified "Jan 10 2012" The Rockbox Crew