I have a customer who recently upgraded his Mark IV to a DKC-900, and wanted to add larger Bluetooth enabled speakers. We used Rockville TM150B 10″ Speakers. Although the speakers are powered, and amplify signal quite well, we nonetheless found the audio output from the Disklavier was a bit low. I added an RCA preamp to amplify the signal going into the speakers. The RCA preamp is zip tied in place using 24″ zip ties. These work wonderfully for strapping components to the beams.
The speakers underneath the piano are present, but are no longer powered or connected.
Yamaha GH actions require the insertion of a “rod” (as it’s referred to in the service manuals). Yamaha sells a specific tools—specifically part TX000671 (VCN03010) during disassembly. The rod blocks the hammers, relieving the pressure on the contacts and contact circuit boards, allowing you to easily remove and reinstall them.
The tool Yamaha sells (TX000671 / VCN03010) is a steel dowel, of a suitable length and diameter to conveniently fit between the hammers and the frame.
Not only is this the correct size to fit nicely in both the Yamaha GH actions, but I actually find it easier to use. The tapered, pointed end means it slips more easily between the hammers and the frame. It’s made of fiberglass, so it’s less likely to cause unintentionally scratches. And in fact, the far end even comes with a ready rubber bumper, just in case you lose track of it and whack a wall with it!
The TX000671 (VCN03010) currently costs $187.0 to the public on Yamaha 24×7, whereas the trusty 48-inch driveway marker costs $3.27 at Home Depot (prices as of 9/9/24). It’s an option worth considering!
The most important part of this step is that you write the files as “Renamed MIDI files.” I typically name each one with the name of the track, and make sure each name starts with the track number (00, 01, 02…). This makes it much easier to keep track of which MIDI file goes with which MP3 later on.
Below, you can see the files listed after ripping the audio CD, and after backing up the floppy disk drive using Player Piano Floppy Backup Utility. The floppy disk tracks are MIDI files and have a .mid extension. These contain the instructions to operate the piano. The CD tracks have been ripped as MP3 files and therefore have a .mp3 extension—these contain the audio.
'01 - Kingston Trio - Tom Dooley.mp3' '01 - Tom Dooley.mid' '02 - Greenback Dollar.mid' '02 - Kingston Trio - Greenback Dollar.mp3' '03 - Kingston Trio - Reverend Mr. Black [1963].mp3' '03 - Reverend Mr Black.mid' '04 - Kingston Trio - M.T.A. [1949].mp3' '04 MTA.mid' '05 - Kingston Trio - The Tijuana Jail [1959].mp3' '05 The Tijuana Jail.mid' '06 A Worried Man.mid' '06 - Kingston Trio - A Worried Man [1959].mp3' '07 - Kingston Trio - Where Have All the Flowers Gone [1955].mp3' '07 Where Have all the Flowers Gone.mid' "08 Bad Man's Blunder.mid" "08 - Kingston Trio - Bad Man's Blunder.mp3" '09 El Matador.mid' '09 - Kingston Trio - El Matador.mp3' '10 Everglades.mid' '10 - Kingston Trio - Everglades.mp3' '11 - Kingston Trio - Scotch and Soda.mp3' '11 Scotch and Soda.mid' '12 - Kingston Trio - (Sinking of the) Reuben James.mp3' '12 Reuben James.mid'
All the files are present, but they will not yet play correctly in the Disklavier, as the filenames do not match.
I wrote a short Python script to automatically rewrite all the filenames to match. Using the numbers at the beginning of each filename, it pairs together matching MIDI and MP3 files and names them whatever the name of the MIDI file is, but without spaces or symbols. This appears to be the same formatting of downloadable Disklavier albums.
Whether you use the script or not, the before and after directory listings indicate how you must rename the files.The script is called using the following syntax:
Note that now the MP3 and MIDI files have identical names for each song, identical capitalization, and that all spaces and symbols have been removed. In the ENSPIRE, unlike earlier iterations of the Disklavier, filename length does not seem to matter. Here’s a graphical representation of the last folder, ready to move:
It’s Time to Play!
At this point, you can move the complete folder (in this case, Kingston Trio) onto a USB stick, and insert it into the front of your ENSPIRE controller.
The Mark IV utilized a spinning hard disk, which was more than sufficient for the technology of its time. Even advanced systems like the Yamaha Disklavier don’t demand exceptionally fast read speeds, as piano notes aren’t played within microseconds of each other. However, spinning hard disks do come with inherent drawbacks. Being mechanical, they are prone to eventual failure, and are noisy. Additionally, during system updates, the limitations of their read and write speeds become evident, resulting in updates that can take nearly an hour to complete.
Whether you’ve chosen to upgrade because of the improved read/write speed, or you’ve simply arrived here because the hard drive has failed, or an update has been interrupted, read on!
First, you’ll need a new solid state drive with a minimum of 80 GB of storage capacity, as well as an IDE to SATA adapter. The 120 GB OWC Mercury Pro Legacy comes with all necessary components. (Note that, although Richard used this, and it fit neatly into the system, I installed mine using a 120 GB Patriot Burst drive and Kingwin SATA to IDE adapter, so my pictures differ. His OWC product is a neat, all-in-one solution.)
Installation
Remove the control unit from the piano by first unscrewing the parallel port connector using the two flat blade nuts on the sides of the port.
Unplug all the cables and then carefully unscrew the control unit from the piano. It is very heavy, so carefully lift it down and turn it over.
Unscrew all the black screws on the top face of the control unit that would normally be against your piano. This surface is the unpainted, silver surface.
Carefully remove the two plugs from the hard drive. Unscrew the drive underneath using a Phillips screwdriver with lots of pressure taking care not to strip the screws.
To create your own backup on Linux or Mac, you can use the dd instruction in a terminal. Note that you’ll need to adjust /dev/sdX to be whatever the location of your hard disk is! On Mac, this will be similar to /dev/rdiskX.
The drive should mount to your Macintosh or Linux computer.
Using the terminal, type in “diskutil list” command shown as below, then press “Enter” to list all the disks in your Mac computer. Take down the number of your USB drive. Here assume that the USB drive number is “2”.
Type in the following command, replacing “#” with your USB drive number.
diskutil unmountDisk /dev/disk#
Then press “Enter” to unmount it.
Type in the following command. On Mac, replace “/path/to/your.img” by dragging the image file from the Finder into terminal. On Linux, type the path. Then press “Enter” to burn the IMG image file to the USB drive.
Unmount your USB drive, put the red adapter back on, and screw it into your Disklavier top assembly. You will need to use the middle screws to give it enough room to be able to have the cable attached and close it.
Voilà! You have now updated your system and changed your drive to solid state!
This Java program will recursively rename .fil files in the specified directory, ensuring they follow the naming convention described, and convert all filenames to uppercase. If, for instance, you have twenty albums, direct this program to run in their parent directory, and all the albums in subdirectories will be corrected.
This script renames all files to be all-caps, and to have names exactly eight characters long. It will add filler characters if necessary. It will make sure they’re unique by incrementing a counter. These appear to be the most important factors in making files identifiable to early Disklaviers, based on my experience and those of commenters.
At this point, you’re ready to use EEXPLORE.EXE to move through each directory and prepare your PIANODIR.FIL. At a future date, I’d like to automate this.
Make certain to back up all files before running this! I can’t guarantee perfect results for all combinations of names and strings of characters.
Windows (EXE): Download and extract RenameForDisklavier.zip. Double-click on RenameForDisklavier.exe, and then select the folder containing all of your extracted albums. It will rename all the .fil files in all the subdirectories.
I recently encountered a Yamaha PSR-S750 with a couple of issues that appear to be quite common in this series. I wanted to share my experience in the hope that it might help someone in the future.
Sudden Shutdowns
The customer initially reported that the keyboard would display an error message at irregular intervals and then require a restart. This issue turned out to be related to a known problem with the main DM board. Apparently, early versions of this board have a tendency to delaminate, leading to errors such as the following:
“Unexpected error! Turn the power off and on again.”
However, the board can fail in various ways, including issues with powering on, sudden shutdowns, and more. The recommended solution is to replace the DM board (part #WZ353701). Unfortunately, this is not a cheap fix—the part currently costs around $503 on Full Compass (as of August 2024), though a Yamaha service provider may be able to offer it at a lower price.
Keyboard Turns On but Won’t Turn Off
This is an interesting issue. The power switch on this keyboard is a rubber button that, when depressed, completes a circuit to ground. Over time, as the button ages and the graphite on its underside degrades, it does continue to complete the circuit, but the resistance increases. Eventually, this high-resistance path is enough to signal the keyboard to turn on, but not enough to signal it to turn off. Diagnosing this issue can be tricky because the button consistently powers the keyboard on, even though it is the source of the problem.
The replacement button is part #WZ960401. Replacing it involves removing the entire front panel, making it a somewhat involved process. It would be wise to have a copy of the service manual on hand before attempting this repair.
Notably, the same issue can occur in the PSR-S770, PSR-S950, and PSR-S970.
Finally, make sure to update your Yamaha PSR-S750 to the latest firmware!Download the latest firmware file, put it on a USB stick, and insert the USB stick into your PSR-S750. Then Power On the keyboard while holding the Start/Stop button (below the LCD screen). You’ll be guided through the update.
I recently installed a Nalbantov USB drive using an updated version of the insert and mount that I designed.
You can see based on the pictures below that the Nalbantov slim is slightly too small to fill the entire cavity left by the original floppy disk drive. Additionally, there are no mounts of any kind to hold the Nalbantov in place. This insert solves both problems: The drive screws into the insert at just the right distance and depth, and the insert also buffers the area around the outside of the drive.
I have a customer who recently experienced an issue with his Yamaha Disklavier HQ100. The HQ100 is the Japanese version of the MX100II. He primarily uses this instrument over MIDI, and finds the Disklavier quite useful.
This discussion should apply to other models of Yamaha Disklavier. The Yamaha MX100A and MX100B use different solenoids, but the designs are similar.
The symptom was that, when started, the Disklavier would play a single key at maximum velocity. It would sustain it for several seconds before releasing. Additionally, the system emitted a noisy whine while powered on. This noise turned out to be a failed power supply, and a replacement resolved that particular symptom. However, despite this, the system would still play one single key after powering on and then fail to respond to any subsequent commands.
The key that was playing was a low D (specifically, D1). I disassembled the instrument and inspected the solenoid for that key. The solenoid assembly was exuding an enormous amount of heat. The burned coil can be seen below.
There was also considerable damage to the inside of the coil assembly. The solenoid was unable to move fully back down into the rest position, as the assembly was badly melted.
I replaced the solenoid; however, this did not solve the problem. The new solenoid would activate and rapidly heat up. At one point, F1 activated instead of D1, adding an interesting twist.
I disconnected CN201, meaning that the Drive C solenoid drive board was still receiving power from the Disklavier but wasn’t receiving a signal. This isolated the problem to the Drive C board. Replacing the solenoids made it clear that they weren’t the issue. Therefore, the problem had to be somewhere on the PCB below:
I traced the circuitry back from the solenoid. In the image above, the D1 key solenoid is plugged into CN207. I verified that diodes D213-D224 were all behaving correctly (between 400-600 mV forward, and 0 back). Eventually, I was able to trace the behavior to the transistor array. My current theory is that the transistor array failed, causing current to run to the solenoid continuously. The solenoid eventually melted the plastic sleeve. This would also explain why the F1 solenoid activated in place of the D1 during later tests—both key solenoids are attached to the same failing transistor array.
I’ve had a couple of people reach out over the years looking for the bracket that supports the Yamaha DKC-850, otherwise known as the “hanger assembly.” The part number for this is, according to Yamaha, WT79210. Unfortunately, it’s been discontinued. However, you can use the hanger assembly for the Yamaha DKC-800, which is a perfect fit for the DKC-850.
The part number for this hanger assembly is ZE383601, and it’s readily available.
I was working on a Roland KR-370 that had been through a lightning strike, and I was looking for the BIN file to program onto a replacement EPROM (IC2). I did eventually find one, posted by a very helpful individual in the Badcaps forum.