[ Monte Myers wrote in 031124 MMDigest:

> I have a PDS 128Plus system. ... The problem is that the PianoDisc
> CD does not seem to play the same way as a normal CD.  I have hooked
> it up directly to the CD player and with a 'Y' from the output.
> I still only get the digital piano signal to the piano but no
> accompanying music through the system.  What am I doing wrong?

I have hooked up many dozens of these in customers' homes, and have
found several ways to effectively wire them.  The CD contains modulated
MIDI (or MIDI-like) data on the right audio channel.  All accompaniment
audio is on the left channel.

I have been told that the accompaniment is stereo, with the left and
right signals both being encoded on the right channel of the CD and
separated into R & L inside the control box (much like the rear
channels of Surround Sound).

In practice, I have found the stereo separation to be minimal.  The
biggest factor in deciding how to connect these components is where
they are located, and what kind and how many cables have been run.

Based on what you have said, I'm going to assume that the CD player and
amplifier are in one location, and the piano and its 128+ controller
are in another.  I'm going to further assume that they ran two shielded
audio cables (not MIDI cables or unshielded speaker cables) to the
piano.  If either of these assumptions are incorrect, please let me
know and I'll revise my advice.

To connect this configuration of system in the factory recommended way,
you actually need four audio cables with RCA ends.  See Method 2 before
fishing another set of cables, however.

Method 1: PianoDisc recommended method.

Connect both outputs of the CD player line out to the control box CD
input, keeping Left and Right straight.  Take the outputs on the 128
into your amplifier.  The box will use the Right channel to control
the piano, and route the Left to the Left and Right outputs with audio
only, as described above.  Don't forget to turn the volume about 3 boxes
off minimum, or you'll get no accompaniment.  Also, there is a line out
volume control on the back of the box.  It's the only knob accessible
without a screwdriver.  Start with it about halfway.

This method works well when the CD is near the piano.  The advantages
are that the "stereo" from the single channel audio can be fully
realized, and that the 128+ Volume and Balance controls will act on
both the piano and the accompaniment.

This method has a couple of disadvantages, however.  The worst is that
when you take a high-end stereo system and run a line-level signal
through a long cable run to the piano, through another component (the
128+) which may not have the same ground potential, manipulate that
signal, and run it through another 20-100 feet of cable back to the
amp, there can be quite a bit of degradation.  This can be helped by
the quality of cable used, care in not running it near other noisy
wires, and using ground loop isolators.

The second problem occurs if you play "standard" CD's through the
system without wiring around the piano somehow.  The 128+ can be set to
automatically or manually change modes for non-piano CD's, but you're
still listening through all that extra cable.

The third problem is having to string 4 wires.  I typically configure
this kind of system in the following way:

Method 2:

Depending on component location, you may need a couple of short RCA
cables, and Y's with different male/female connections.  Select 2
inputs on your amplifier, such as CD and Tape 2 or some other unused
input.  (I'll keep calling it Tape2 but DVD3, Aux, anything but the
Phono connection will do.)  The CD button will be used for normal CD's
the Tape 2 will be for Piano CD's.

Using 2 y's, Connect the Left channel of the CD player to the Left
CD-in on your amp, AND to the Left AND Right Tape2 input on the
amplifier.  Using 1 more Y, connect the Right output of the CD player
to the Right CD-In on the amplifier, and to one of the cables to the
piano.  Connect the other end of this cable to the CD-IN Right on the
128.  Read the words on the 128, don't go by the colors.  I think Right
is on the bottom, but there was a series of boxes in which the top was
colored red.  All other RCA connectors will go unused.

Advantages of this method are the lack of noise/hum, and easier cable
runs.  You do lose the stereo separation of the accompaniment, but like
I said, there isn't much of that to begin with.  The volume on your
stereo will only control the accompaniment.  The volume on your piano
will only control the piano.  Less controls, but some think easier to
balance.

If you're hearing digital tones through the stereo, don't forget to
press the "tape 2" input selector.  If you're not getting any
accompaniment, check to make sure the PianoCD has it in the first
place.  Many are piano only.

Let me know if you have any more questions.

David V. Anderson, RPT
Milwaukee, WI
andrsn@wi.rr.com