My DX7 is having troubles with midi. I can't load any patches to or from my PC. I have SBLive with a midi interface connected to it. The DX7 is sending midi events out correctly, if it's played "nicely", but when several notes are played rapidly or mod wheel is moved, it gives some strange controller and aftertouch messages.

Has anyone experienced similar problems? I'm wondering if the problem could be in the coupling circuitry of the midi in/out.

Sounds like you're experiencing MIDI data "overload". This can be caused by MIDI data feedback, if you have both MIDI-in and MIDI-out connected, and your MIDI interface and/or software enable a MIDI Thru function.
If that's the problem, the usual cure is to turn "Local Control" on the synth "off". Unfortunately, the original DX7 didn't have a "Local off" function, although the DX7II does. If you can turn local off, try that. If not, you might have success by seeing if the MIDI interface or software allows the Thru function to be disabled. If that can't be done, you could try pulling the MIDI cable which is not being used at the time, depending on which way the data is going. That approach may or may not work if the application requires "handshaking".

--Barry

Thanks...

but it's not the problem. It also happens with only one cable. I'm afraid there's something wrong in my DX7 or SBLive...

Do they know how to service these equipment in those equipment servicing places anymore...? The thing is getting a bit old, but the electronics used is very simple.

It's not impossible that you have a hardware failure, but I'd suggest trying other things before going the repair route. I'm assuming that you're using "known good" MIDI cables.

Did this difficulty occur recently? Had you been able to previously send and receive SysEx messages without problem? If so, have you made any hardware or software changes since the time when things worked?

Early DX7 units sent "Active sensing" (FEh)messages all the time, which can add clutter to the MIDI data stream. (I believe that a replacement ROM allowed that to be controlled.) You might want to see if it can be turned off on your DX7. If not, perhaps it can be filtered out by your software.

If you already have backups of any "user" material in the DX7, you might try doing a factory reset on it in case something you haven't considered is misconfigured.

Maybe you need to elaborate, but your description sounds normal. When you play hard you should get aftertouch. When you move the wheel you should get controller messages.

Steve

Steve, I agree, but the OP said "I can't load any patches to or from my PC." in addition to getting "strange controller and aftertouch messages." That's why I asked for further info, which unfortunately hasn't been forthcoming.

Kennyboy, if you're still having problems, a few more details might help get things resolved. Let us know.

--Barry

The cables are working ok, that's for sure. I had a midi keyboard few years ago and everything worked fine.

I built a simple midi tester that blinks a led when there is coming signal from the dx7. Indeed, it seems that there is some activity all the time. Must be the active sensing thing...

The sysex sending/receiving tools (Midilib, DX manager, MIDIOX) I have been using doesn't apparently show these active sensing messages. I also wasn't able to find a way to filter them out. Is there any recommended software for monitoring midi messages?

Thank you!

One thing I just figured out is how to filter out the active sensing messages in MIDI-OX. Unfortunately MIDI-OX isn't showing any active sensing messages even without the filtering. The sysex messages that should come out when pressing "midi transmit? --> yes" (sys info set to available), can't be seen in the midi input monitor.

DX Manager is showing the continuos activity of the midi channel, but lacks the property of showing the type of the message. It just says "Midi long message error - invalid sysex".

The "strange" messages I was talking about are really strange... I mean that when I tweak the mod wheel, I get random midi messages from random midi channels. There's control change messages, start and stop messages, aftertouch messages, note on/off messages... The same occurs when several keys are pressed quickly, not meaning hard.

Oh, I should mention that the problem has been there since I bought the device about a year ago.

Thanks again!

Well, that certainly is bizarre behavior. I have a few more questions before offering further suggestions.
1) Do you have the owner's manual?
2) Have you tried a factory reset?
3) What happens (what does the readout say)when you enter Function mode (press the "Function" button)?
4) Are there any signs that the unit has been modified or damaged?

--Barry

1) I have the user's manual and the service manual in pdf format.
2) No, because I don't know how to do it. I couldn't find any instructions anywhere.
3) Ummm... do you mean the readout of the lcd display or the readout of the midi software? After pressing the Function button, there is a text "FUNCTION CONTROL | MASTER TUNE ADJ" in the lcd. The software doesn't react at all.
4) No modification or damage can be seen.

1) I have the user's manual and the service manual in pdf format.
Okay, otherwise I was going to tell you where you could find them.

2) No, because I don't know how to do it. I couldn't find any instructions anywhere.
First, I should warn you that a reset will initialize all the user data, which means there will be no voice patches loaded when you are done. You probably shouldn't try this unless you have the original voice ROM, since if the reset doesn't fix the MIDI problem you won't have a way of reloading. I don't own a DX7 myself, but I've heard that pressing and holding down the "Edit", "16", and finally "32" buttons and then releasing them all will get you to the reset. I've also heard that similarly pressing Function/16/32 provides access to diagnostics.

Hopefully, Steve (who is Yamaha's tech guy) can verify (or deny) this info.

3) Ummm... do you mean the readout of the lcd display or the readout of the midi software? After pressing the Function button, there is a text "FUNCTION CONTROL | MASTER TUNE ADJ" in the lcd. The software doesn't react at all.
I meant the LCD; I asked because I wanted to determine if your unit had a Grey Matter E! board in it. From your response, apparently it doesn't.

4) No modification or damage can be seen.

Well, hopefully that leaves out problems caused by physical shock or the like.

The DX7 has a lithium battery used for RAM back-up purposes. The don't usually last more than about 10 years, although sometimes a bit longer. I'm not familiar enough with the DX7 to know if strange behavior could be related to a weak (or leaking?) battery, especially if the user data isn't being lost when the synth is off. Perhaps Steve could weigh in on this as well.

Good luck with your problem.

--Barry


[This message has been edited by quietDIN (edited 02-20-2005).]

First, I should warn you that a reset will initialize all the user data, which means there will be no voice patches loaded when you are done.
That's ok, I have the original voice cartridge.

I don't own a DX7 myself, but I've heard that pressing and holding down the "Edit", "16", and finally "32" buttons and then releasing them all will get you to the reset.
Unfortunately, that's not working on my DX7.

I've also heard that similarly pressing Function/16/32 provides access to diagnostics.
Well, that's working, but isn't giving me any needed information.

The DX7 has a lithium battery used for RAM back-up purposes. The don't usually last more than about 10 years, although sometimes a bit longer.
The battery is ok, "battery check" function gives 2.8 Volts

I'm not familiar enough with the DX7 to know if strange behavior could be related to a weak (or leaking?) battery, especially if the user data isn't being lost when the synth is off.
Could that be one way to reset the device? If the battery is removed, all the data in the RAM should be erased...

One solution to the problem could be the E! board and it would also give some extra functionality to my dx7. Unfortunately they are very hard to find these days, I assume.

Maybe I'll try to remove the battery, unless someone advises me NOT to do so...

Thanks!

The MIDI problem you are seeing is very strange and sounds more like a circuit problem than a software problem in which case adding an E! board probably wouldn't help and I don't think your chances of finding one of those a very good. About the only one you would be likely to get would be buying another DX7 with one installed.

While I don't think removing the battery will solve the problem you may as well try it.