Piano World Home Page Forums Our Most Popular Forums Piano Forum PianoDisc question

Hi everyone.

I'm seriously contemplating buying a Petrof III with a Pianodisc system installed. The problem is that the Pianodisc system is an ancient PDS-128. I haven't seen a floppy disk in years!!

My only two needs with a Pianodisc system are:

1) Have the piano play itself via MIDI if I connect a computer and run my own software (e.g. PGMusic products)
2) Record my own playing on the Petrof (in MIDI format), send those notes to a computer (again running my own software)

Apparently the piano does not have the TFT recording strip, yet the PDS-128 manual and the seller both claim the piano can record. I was wondering how this is possible. Apparently it records directly to diskette (which is not what I want, I want MIDI), but how can it even physically record if there is no recording strip?

It can't. The TFT strip is not my favorite technology because it affects the feel of the keys by a significant amount. The QRS PNOscan and PianoDisc supported Magic Star systems are optical.

Here's a different solution...the QRS Pianomation II upgrade kit will also work for old PianoDisc systems like the 128. This is a bit of a shocker. With the PMII, you can control the piano with any web-enabled device (computer with wi-fi, blackberry, iPhone, iPad, etc.)

This is interesting (maybe distressing) to me as I have the Pianodisc record option on order for a brand new IQ System. I had not carefully investigated, but just assumed the system was non-intrusive, that it was either optical or otherwise had no impact on playing.

Does it really? Have you tried it?

I found at another website a more technique description. NOT the Pianodisc web site so I do not know for certain this is true, and offer it with a big caveat. The site was dated 2005. I could find nothing specific to this question on the Pianodisc site. Below the line is what I found, and does indicate that actual key movement pressure is used to generate the signal (as opposed to say an optical sensor).

Can someone who has played one before/after comment (Sam that may well be you, did not mean to imply I assume otherwise).

-----------------------------

03. TFT RECORD STRIP (midi)
The TFT sensor strip, which PianoDisc calls Touch Film Technology, consists of four pieces of piezo polymer film. Each piece is screen-printed with conductive carbon ink on both sides, resulting in a pattern of 22 sensor "fingers." The four films--only 28µ thick and about 1.5 inches wide--mount within a long flat piece of extruded aluminum having a slight convex upward curve where the sensor fingers meet the piano keys. The sensor strip has relatively no effect on how the piano feels to a player.

The with are sandwiched between the aluminum strip and four printed circuit boards (PCBs). Corresponding electrode pads on the PCBs press directly on the carbon ink sensor surfaces to achieve electrical contact. The PCBs also contain eight analog-to-digital converters, each scanning 11 of the sensor fingers. The system scans each sensor at a rate of 961 times per second.

The sensor strip sits under the keys near the movement's fulcrum, where the total range of key motion is only about 10mm. Each keys rests on a sensor, preloading it. The sensor strip fingers are carefully positioned to avoid picking up motion from nearby keys.

When the pianist strikes a key, its movement slightly stretches the piezo film sensor over the convex cross-sectional curve in the aluminum strip. This action develops a voltage in the sensor, whose magnitude varies with the force (acceleration) of the key stroke. The velocity and duration of each note played are meticulously decoded and translated into MIDI data.

After the sensor voltage rises above a predetermined threshold, the CPU will start collecting data for that key. The threshold is set high enough to avoid triggering by ambient noise, and low enough to capture subtle keyboard movements by the pianist. The system has sufficient sensitivity to distinguish between accidental brushing of the keys and softly-struck notes.

The CPU keeps a running check on sensor voltages beyond the threshold, noting whether they are increasing or decreasing, and accumulating a rough integral of the voltage waveform. When a sensor's voltage reaches a plateau or starts to decrease, the key has hit the bottom of its stroke and the hammer has struck the string. At this point the CPU infers the MIDI velocity based on the maximum sensor voltage, assigning a value between 0 and 127. For example, a value of 10 would represent a soft note, while a value of 110 would represent a loud one. Meanwhile, the CPU continues to follow the sensor output, checking for the time that the pianist releases the key. The sensor develops a negative voltage at release.

The PianoDisc system includes a switch sensor to determine and record whether the damper pedal is on or off. During playback, a separate solenoid mimics pedal action by raising all the piano's dampers. This permits the strings to continue to resonate after the release of a key.

The TFT (Touch Film Technology) affects the touch by about 3-7 grams...an increase of 6%-15% of average proper touch weight. Magic Star is a silent system, but will work as an optical record system alone.

Does it just make it uniformly heavier, or does it make it feel less smooth, e.g. does it add any kind of jerk or bump or unevenness to it?

Does it slow the return of the key, making it less quick to re-strike the same key?

I could probably live with (say) 10% more effort, but I do not want it to slow down the action beyond that, or have a rough feel.

PS. I assume if I want record, having already bought all the rest, it is really my only option -- take it or leave it.

The TFT technology works well, but it is a noticeable change to the feel. Since there are better alternatives, we now use those and I suggested them to you. There's not a real cost benefit to the TFT, so why bother at this point? It's also mechanical, which introduces another potential failure point down the road. An optical system without moving parts just makes better sense. Repairing an optical sensor usually involves a spray can full of air.

It would be hard to answer your other questions of how the different it will feel to you...to yours or my satisfaction.

Sorry, maybe I am being dense. If one has the newer PIanodisc IQ system, brand new and bought and already installed, are you saying these other systems are compatible and could be had instead of JUST the TFT system?

I was assuming your comments were an alterantive to Pianodisc entirely, something not an option for me (but may be for the OP, and I apologize if this discussion has hijacked the thread).

But if I could simply replace the TFT itself with something optical and have it be plug compatible with the rest, that would be great.

Note that the TFT was also to be the source for triggering the accompanyment in Pianodisc.

Yes.
Not sure what this means? What kind of accompaniment?

Thanks for being patient and the information.

As to the latter, I am asking about what I think is QuietTime Magic star, which is an electronic piano device that allows you both to silence the acoustic piano and play thru headphones, and also to play the acoustic piano while generating one (I think only one) of 128 other voices such as strings, drums, etc. based on the notes you hit.

There is little info I can find, but my impression is that this requires the TFT system.

I am actually less interested in the TFT for recording, than for silent practice and/or accompanyment, to keep things more interesting as we learn.

No. You're not getting it. You are very, very confused.

They are either/or systems. System isn't even the right word for the record strips. The record strip is either optical (PNOscan & MagicStar) or mechanical (TFT). The output is MIDI signals. MagicStar is a system because the record strip is ready to go with the sound module and silent rail. The TFT or PNOscan require sound modules and silent rails...a la carte.

You cannot really use the system to accompany the piano with other sounds. The silent rail is either active, so there is no actual piano being played and you can use the sound module to generate any of it's tones. Or it is not active and the piano is playing. At most, you can use the system to layer sound module tones over the regular acoustic piano. You cannot play one part piano and one part organ simultaneously, for example.

I may be using the wrong terminology. I described what I want, the dealer said he would get it. This morning I looked on the web site trying to find the names, and may be picking them incorrectly.

Can you help clarify then. What I asked to be able to do:

1) Silence the acoustic piano and practice with headphones

2) Play the acoustic paino, and have the device play the same notes but with different voices, one at a time (e.g. strings). This was demonstrated on the Mark IV Yamaha (but it can do three at a time).

3) Plan the piano and produce a Midi recording. Of these this is the least important (and I thought a normal part of the above).

In order to do these (at least (1) and (2)), I read your postings as having a requirement for the TFT strips which would of necessity change the feel of the piano.

I also had the hint that I may be able to keep the Pianodisc unit that does the playing, but buy some different sensor so as not to change the feel, but retain some of all of these features.

Does that help at least clarify what I want?

And (with advance thanks for your continued patience), do you have a recommendation how you would proceed, given the base IQ unit is in and working terrifically?

From your list...

1) IMO, the best aftermarket system is the MagicStar because how the silent rail is mounted. I don't think any of the aftermarket systems sound particularly nice compared to the current crop of better digitals.
2) What you describe is an exclusive to the E3 and Mark IV Disklavier systems if I understand your description. The iQ doesn't do that.
3) Any optical or TFT record device will give you the option of MIDI out.

TFT does only one thing...convert your keystrokes into MIDI out.
And again.
TFT does only one thing...convert your keystrokes into MIDI out.

What are you using to control your iQ system? Is it wireless? If it is wireless, you'll have a whole new set of complications trying to build onto the iQ because it has only 1 input which is currently being used by a wireless router (probably Apple Airport Express).

I don't know if I can help you or not, but there are some limits to the iQ system. You can either have it be simple and hidden (with wireless option) or you can have it complicated by more features with some visible components.

There are 9 different pre-packaged iQ systems + an even larger list of upgrades and accessories. You need a consultant and a map.

Thank you. Re (2), that's a disappointment.

With regard to the latter, my wife plays it with an iPad, it does use an airport express, so I can actually play it with any device on our home network (computers I can do).

It sounds like I need a long conversation with the dealer.

Thank you again.

Linwood,

I found out that indeed the MagicStar system from PianoDisc uses optical scanning not TFT. This is the system I ordered for your piano.

I suppose now the discussion of specs would be a moot point as to how the TFT might affect touchweight but the rep at PianoDisc agreed with my position that it would not be detectable.

I was surprised about the optical scanning for the MagicStar but apparently it is outsourced and has been successful. It will enable the piano to function in 3 different ways:

1) Play the piano as if it were a digital but using headphones. The sound you select is only heard through the headphones.

2) Play your piano out loud but change its voice. By engaging the mute rail, you only hear the sound that you select through the speaker.

3) Play the piano out loud and with an accompaniment sound that you select which is heard through the speaker. The mute rail is not engaged, and you select one of the 128 midi sounds that are included.

Thanks,

Nick

That's terrific, Nick, I can't wait to get it in (hint hint!).

We hooked it up today to the home stereo, which makes a huge difference in the player pieces which have vocal or other accompanyment. We've been having a great time with it, it's all nicely networked with our home network (encrypted too, just because), so ready any time for the rest of the toys<del><del><del> necessary accessories!

Thank you for following up on this, including posting publically.

Nick sold me the piano and Pianodisc, and has been amazingly patient. Those of you who are dealers should never sell to an engineer -- they ask too many questions.

I have had the system now long enough to understand it a bit.

Just in case anyone looks here for details:

- I got the MagicStar S Quiettime, plus the Pianodisk IQ

- The MagicStar came with keyboard sensors which do not appear to be either of those described above. They are small (say 1-2mm) wide rigid plastic on a pivot point. The key pivots the plastic, and some magic happens to sense it.

- There is no perceptable difference in key press; I cannot mesasure a difference using coins. I am very happy with the lack of difference.

- Pianodisc apparently never planned these two systems to be used together -- there is a complete lack of information on connecting them, and calls to their tech support yielded only modest success.

- I did NOT find a way to record with the Quiettime itself and play back through the IQ system; it will play back to an audio system instead.

- The Quiettime will quite nicely play an accompanyment with manual play of the accoustic piano. Strings in particular sound very nice but it has many sounds. One at a time though.

- It is possible to record from the accoustic keyboard to a Midi sequencer, and play back through the IQ. With a lot of quirks, but once working it works VERY nicely.

This has been very educational. I have most of the bugs worked out, the only thing left is some bad hummmmm I need to pursue. Describing all the details would be a (long) topic in itself. Short version: very happy with the result, very disappointed Pianodisc had such lousy documentation, and lack of planning to use their own devices together.

And extremely impressed with the hard work that Dan had to go through to get the mute rail installed!