Disklavier

Hi All
My name is Peter Phillips. I live in Sydney and own a MKII C7 DKV with an
XG control box. I used to own a PianoDisc (sold to make way for the DKV)
and I also own an Ampico pneumatic reproducing piano. I've been a member of
this group for some time, and would like to make a contribution in two
ways. The first is MIDI music for the DKV.

I'll keep this brief, as I don't want to appear to be selling. I think you
will find my website interesting. It's at www.petersmidi.com. There are
sample files that can be downloaded, along with catalogs and background
info. The music is optimised for replay on a DKV, and there's heaps of it...

My second contribution will interest those who own instruments with the
optical record system. I purchased my DKV secondhand from a friend, so I
was aware of its record and playback problems. I have a technical
background and have been involved with pianos for over 30 years, so even
though I am not a DKV technician I felt capable of fixing these issues.

I have all the manuals for the instrument, so I started by checking the
points at which the hammer flags were being detected. As you all probably
know, this can be done at the control box, in which you raise a hammer and
note how far the hammer is from the string when a beep sounds. This should
be 2mm, but in my DKV it was around 7mm! The problem was, there was no
further adjustment to correct this.

The answer was supplied by Leigh Whitely (a member of the group). I had by
now contacted Yamaha, as it was looking as though my DKV had been fitted
with the wrong hammer flags. Leigh conducted tests on another DKV and rang
to explain that there are two beeps! Ignore the first and listen for the
second. This is not explained in the Yamaha manuals. Once I was aware of
this, it was all too simple, and before long I had my DKV sounding as never
before.

It's interesting as to how much the hammer sensor position can affect the
playback. But once it was all set correctly, it was amazing just how well
the DKV performed. Its previous owner (who bought a C7 DKV Pro), thinks my
DKV now plays as well as his. If only Yamaha would get someone to proof
read their manuals!

But there's more... And this one is more serious than you might first
think. It's to do with the lifespan of the LEDs that provide the light
source for the optical record system. I'll keep this brief, as it can get
rather technical. Basically, after a few months I discovered the playback
performance I was so proud of was starting to sound rather ordinary. 

More investigations found that some of the hammer sensors were not working.
There was no consistency in the errors, but after a lot of experimenting
and head scratching, I decided to replace all the transmitting LEDs (12 of
them). The question was, what with?

The original LEDs are high-intensity types, but even when new, these are
just on the edge of being operational. These days there are numerous types
of high intensity LEDs available. The device I settled on is a 20,000mCd
hi-output LED made by Vishay. Cost each was AUD2.70. After replacing all 12
LEDs, all problems were solved. A tricky task, but totally worth the effort.

We tend to think of solid state as being forever, but LEDs have a definite
lifespan. So if your DKV has the optical record system, be prepared for the
day the LEDs start dying.

PS: I claim to be the first person in the world to computerise a piano.
It's all on my website, including pictures and brief background. See
www.petersmidi.com.

Peter Phillips