Macbook Pro optical out at 48khz? Can it be down-sampled to CD 44.1?

[Twitchy_one]

I got a really strange issue here.  I have a USB to optical converter
& when I plug that into my TDK cd-player it'll record just fine.  However,
if I plug the optical output directly out of my MBP into the TDK, it will
not record.  At first I thought my TDK was just dead, but I went back
to USB-to-optical converter & tried again & noticed that it all worked.
 
Is this an issue with the MBP not down-sampling?  I'd like to get away
from the USB-to-optical converter as the slightest wiggle of a mouse or
a scroll bar can cause the music playing to jitter.  When played directly
through the MBP, I can use the MBP normally & it doesn't affect the
output from the MBP.
 
Would anyone know of a DAC with passthu optical that might work,
something to, I guess, lower the sample so that the dang TDK will
work properly?
 
Thanks for any suggestions or advice.
 

 

[Yoga Flame]

Applications > Utilities > Audio MIDI Setup
 
You can use that to change the sampling rate. My not-so-new Mac can do optical out at 44.1K, 48K, and 98K.
 
Some applications can change the sampling rate without telling you. Skype does this on my Mac and sets the rate to 48K whenever there's a call.
 

 

[Twitchy_one]

Thanks Yoga. I was googling all over trying to find that piece of info.
After lowering the sample rate to 44.1 & 2-bit, 16-stereo, the dang
TDK still didn't like it.  The sound came through, but when I setup the
record to pick up on a transmission, it just sits there not recording
a single second of sound.  No "D-unlock" error, just no error
basically.
 
I decided to plug the TDK to one of my Outlaw 990 preamp's digital
outputs & there was no sound at all there.  I guess I should be amazed
the TDK has ever worked.  Maybe the TDK is too old & I need to look at
some alternative recording devices, or switch to analog with the
TDK instead of digital.
 

 

[Twitchy_one]

I think I figured out what was going on so I thought I'd come back &
report it to HF.
 
What is happening is the optical output is switching off when it's not
playing a sound on the Macbook Pro (MBP).  When I select optical
for the input source of the TDK CD Recorder, it reports back "D-Unlock",
which is what you get when nothing is input into the TDK from the
selected source.
 
Now when I play a sound (youtube or whatever), the TDK picks
it up & starts playing.  And if I go back & select the optical input
again it shows 48Khz, so it's picking something up.  But for whatever
reason, when I ready a recording track, it never records because I think the
optical output cuts off before the sound plays & this causes the
TDK optical input to register back as "D-Unlock"...basically that the
TDK has once again lost the signal.
 
Now what I've noticed is that the Xitel USB (to optical/coax/rca)
device is _always_ on. Once I plug it into the USB, you can see
a red light coming from it when nothing is playing.  The TDK registers
the Xitel at 48Khz (it has no way to change that frequency btw)
& the TDK will record without fail.
 
I've also been noticing a stutter to the sound with just the optical
output on the MBP (without Xitel), so it seems to be the laptop
itself can cause the issue, as far as I can tell.  If I keep the majority
of apps closed when doing a recording, I can probably minimize or
eliminate the stutter.
 
This would also explain why passthru optical from the MBP to
a preamp processor would not make a change as the preamp
would turn its beam off when it wasn't receiving a beam from the
MBP.  So to get the TDK recorder to accept a signal, I need any
USB to optical device to have its own beam always running.  If
the optical signal is energy efficient, the TDK gets hosed up.
 
What a pain, but at least it makes sense now.