[joe h]

Hello,

Thanks for all the insights regarding the dbx376 and it's somewhat-
kooky 330ohm input impedance. This has promted me to go in a
decidedly up-town direction:

The Focusrite ISA-430 mkII. It has a digital output card:
http://www.bhphotovideo.com/c/produc...MKII_AD.htm l

It looks like if you want to run spdif, you use the "Toslink" output.

The Macbook specs say that:
Optical audio input is SPDIF format and uses a standard toslink cable
with a toslink mini-plug adapter, accepting up to 24-bit stereo and
44.1-96kHz sampling rate.


The words "mini-plug adapter" jumped out at me. I looked at this input
jack on my Macbook carefully. It looks just like a 1/8" sony walkman
style headphone jack input. So maybe I need a "toslink rectangle
looking" plug on one side for the Focusrite, and a "1/8 inch walkman
style jack" on the other side for the Macbook.

So I found this cable on the Markertek site:
http://www.markertek.com/Cables/Audi.../OPQ-205.xhtml

Do you think that's the right cable to connect the Focusrite to the
Macbook?

[Mike Rivers]

On 8/29/2011 11:57 AM, joe h wrote:

The Focusrite ISA-430 mkII. It has a digital output card:
It looks like if you want to run spdif, you use the "Toslink" output.

The Macbook specs say that:
Optical audio input is SPDIF format and uses a standard toslink cable
with a toslink mini-plug adapter, accepting up to 24-bit stereo and
44.1-96kHz sampling rate.

The words "mini-plug adapter" jumped out at me. I looked at this input
jack on my Macbook carefully. It looks just like a 1/8" sony walkman
style headphone jack input.

That's right. The damn cheapskates saved the cost of making
another hole in the chassis by putting a TOSLINK receiver
chip behind the mini jack so the same hole could be used for
both an analog and a fiber optic cable. There are indeed
adapters that fit on the end of a standard TOSLINK connector
and are shaped like a 1/8" phone jack. There are also cables
with that mini jack configuration on one end and a standard
TOSLINK connector on the other. That's what I'd recommend.

The cable you located should do just fine, at least as fine
as that version of the technology is capable of. TOSLINK
isn't the greatest physical interface, nor is the mini jack.
But at least you don't have to worry about electrical contact.


--
"Today's production equipment is IT based and cannot be
operated without a passing knowledge of computing, although
it seems that it can be operated without a passing knowledge
of audio." - John Watkinson

http://mikeriversaudio.wordpress.com - useful and
interesting audio stuff

[joe h]

Thanks, Mr. Rivers.

You really know a lot about circuits. I'm glad it looks like I zeroed
in on the right cable.

It does seem like a fragile type of interconnect. This is mostly
(completely?) going to be for a fixed location where I won't move it.
Plus I tend to be really careful about equipment. So I don't think I
will break anything. But it's a great point to bring up that these
type of interconnects should be treated carefully since they are not
as big and robust as a xlr mic jack.

It's good to know the toslink connect on the Focusrite A/D card is
some sort of dual-use input. I'll make sure to be careful with that
connection.