Yamaha U3 MX-80 Disklavier

[NikkiC]

I purchased this model a couple of weeks ago from the guy in Chorleywood (20 minute drive from me). It appears to be in excellent condition. The Disklavier system functions well, except in one area. The midi values recorded from its sensors are lower than those required to play back the notes at the recorded velocity. If I hit C4 and it outputs midi velocity 80 then that value needs to be multiplied by something like 1.15 to have it play back correctly. The volume function is the first thing I checked. Tweaking a compressor in a sequencer allows recordings to play back as they were recorded, but we lose a bit of definition, not that I can notice. Actually, I can live with this, given this is an old system. Downloaded midi files do not have to be tweaked for them to sound 'correct'. Midi sequences recorded on my Clavinova and played back on the MX-80 sound fine too. It's simply the MX-80 recordings are flattened dynamically. Is this intentional?

I have a service manual for the MX-80. The calibration only goes as far as setting the dynamic extents. There doesn't appear to be a calibration function for setting the required solenoid force to match the recorded key velocity value. There so easily could be as the hardware provides all the required data, regardless of its dated technology. The control box gives a date of 1993 for its last I/O test. The U3 serial number is dated 1994.

I'd like to know whether I am missing some functionality. Any ideas anyone?

[mdw]

I the guy you purchased it from was a trader then I guess thats where you go for this info.

[NikkiC]

I will be contacting them soon. I'm just waiting to get over a bad cold and cough that has practically knocked out coherent speech. However, I always like to do background research so that I am armed with some useful knowledge first.

[NikkiC]

Just spoken to the seller. He doesn't actually know how to calibrate this Disklavier. Something I had suspected. He says he's contacting some technicians in Japan on how to perform a calibration, if this is even possible at all. That could take more than a week or two.

I've checked every service manual and cannot see a method to calibrate this Disklavier. I'm beginning to suspect it can't be. Unless physically adjusting the sensor rail does anything meaningful to captured velocity values.

In the meantime, if anyone has any clue I'd be grateful.

[athomik]

The MX80 calibration procedure is a bit involved and long-winded compared to more modern ranges. Send an email to adrian.thomas@gmx.yamaha.com for more information.

[NikkiC]

athomik,

You're a star. Just the little piece of information I needed to get me started. I'm very grateful. I will try this contact.

[edit] Oh, the contact is you! Silly me!