Have questions about 7-pin cables, how they're used, the difference
between "active" and "passive" cables, daisychaining, the various cables
that Sony offers, and those available from Core Sound and other vendors?
This page is intended to help!
On the DAT-heads mailing list, this request appeared:
I was just wondering what the deal with the Sony M1 & D100 is, and
patching at shows.???
I have heard sometimes you can patch first in line, and feed d8's and
others say you need to be in the back of the line due to voltage
differences and other sony logic stuff.
I have also heard that sometimes it has trouble locking onto a
digi-signal sent by an Apogee and other times not. Are both of this
issues solved by just buying an [another manufacturer's] passive cable?
As with many Sony issues, the answer is a little complicated. The
complication stems from the fact that Sony decided that, while its
portable DAT decks ("DATmen") comply with the S/PDIF
data format
standard, they do not comply with the S/PDIF
voltage level standard.
Adding complication is the fact that successive generations of DATmen
are not voltage compatible with earlier generations.
Here's a little history that should explain:
The Sony TCD-D3 was the first of the Sony portable DAT decks to use the
7-pin I/O connector. It used much higher voltage levels (roughly 5.2
Volts) than the S/PDIF standard's .5 Volts. Sony provided two interface
cables: the RK-DA10 which was an "active" (voltage level translating)
cable to allow the -D3 to accept the lower S/PDIF-standard voltages; and
the POC-DA12 cable with Toslink (fiber optic) input and output.
The next generation TCD-D7 and its successor, the TCD-D8 (solving most
of the -D7's transport problems), used slightly lower voltage levels:
around 4 Volts. The same two cables worked fine with them.
The next generation is the current one: the TCD-D100 and the pro
(SCMS-free) PCM-M1. It uses a still lower voltage: 3.5 Volts. The old
cables won't work on this voltage so Sony issued new ones: the RK-DA10P
for coaxial (RCA) input, with a gray casing instead the older RK-DA10's
black one; and a variety of POC-DA12x cables, each having a different
suffix:
- POC-DA12P is 7-pin to optical Toslink digital in/out
- POC-DA12MP is 7-pin to optical Miniplug in/Toslink out
- POC-DA12SP is 7-pin to optical Miniplug in/out
There are also third party suppliers of 7-pin cables.
The Oade Brothers and one or two other shops have started with the Sony
RK-DA10 (black casing) and RK-DA10P (gray casing) active input cables
and added a passive output. Since the outputs are passive, the
voltage the cable will provide depends on the model of recorder you're
using. If you use a -D3 it'll be 5.2 Volts. If it's a -D7 or -D8 it'll
be 4 Volts, and if its a -D100 or -M1 it'll be 3.5 Volts.
Core Sound provides the widest variety of cables, but they're all
passive. "Passive" means that they do not translate voltage levels.
They are not based on Sony's RK-DA10 but rather on Core Sound's own
7-pin plug. The plug does not have the metal shield around the pins
that Sony's plug has, and so is a bit less rugged. Even so, thousands
of the cables are in use and they have proven reliable over 6+ years of
use.
Again: There are no cables that are active (voltage translating) for output.
So what can you hook your deck up to?
The rule is that higher voltages can feed lower voltages with no
problems. Since the DATmen have higher voltages than the S/PDIF
standard, all Sony DATmen can output to other S/PDIF devices (e.g., CD
recorders and S/PDIF soundcards with coaxial inputs) reliably and with
no need for active cables.
In contrast, for a strictly S/PDIF compliant device to feed a DATman,
you'll need an active input cable for your DATman. Luckily, most common
non-Sony and Sony-non-DATman DAT machines put out much higher voltages
than the S/PDIF standard. For example, Tascam DAT decks (DA-P1, DA-20,
DA-20II, DA-30, DA-30II) all will output to all Sony DATman reliably,
without active cables. And most Sony home DAT decks (e.g., DTC-A7) do
the same.
Most home CD players however, are strictly S/PDIF compliant and you'll
need an active cable to feed your DATman.
What about daisy chains at shows?
If you are in a daisy chain consisting only of DATmen, if you have the
correct active input cable for your deck, then you can reliably accept
signals from any of the other DATmen.
If you are using a passive input cable, remember that only older
generation decks or ones of your deck's generation will reliably feed
your deck; you probably won't be able to accept a feed from a deck of a
later generation. So, if you have a -D3, you can accept a feed from
another -D3. If you have a -D7 or a -D8, you can accept a feed from a
-D3, a -D7 or a -D8. If you have a -D100 or an -M1, you can accept a
feed from any machine. (This is the origin of folks wanting some
machines to be at the tail of the chain and others at the head.)
For mixed active/passive chains, remember that all cables are passive
on output, so even folks with so-called "passive" cables can feed all
active cables with no problem. For example, you can have an -M1 with a
passive cable at the head of a chain, feeding a -D3 with an active
cable. That -D3 can then feed a passive -M1 or any other combination of
decks and cables.
Remember that if you have a TCD-D100 or PCM-M1, and you need an active
input cable, you must buy a cable based on the RK-DA10P with the gray
housing; the older RK-DA10 with the black casing may or may not work.
I hope this helped!
(Last updated 08/24/2005)
