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Broken EX800?

Broken EX800?

2015-10-15 by slushprodukt@...

Hi,


I'm hoping people will be able to advise me about the state of my EX800 and the likely chances of getting it back into working order.


I bought an EX800 on eBay a month ago. After it arrived, I wrote a computer program to control it over USB MIDI. I was able to trigger notes, both on and off, although I never managed to modulate the VCF (the manual says this is option 3). Anyway, a few days later I was experimenting with my software and suddenly, for no apparent reason, the EX800 seemed to crash. It made a crazy sound which I could only stop by switching the synth off.


When I switched it back on, I realised that all the "programs" had been scrambled. Going through the parameters, many of them are now nonsensical (eg. a value of 4 when it should be either 0 or 1). Most of the patches now sound exactly the same: noise, no DCO, with some fast MG filtering.


Much more importantly... The synth is no longer capable of producing a sawtooth wave. It just sounds exactly the same as the square wave.


It's strange, but I guess an accident like this is to be expected with a 31 year-old synth.


This is my first time using an EX800. I have no experience with it or the Poly800. Has anyone seen problems like this before?


I was going to buy the Hawk800 and Atomahawk kits anyway, but now I'm wondering two things. Does this EX800 have a permanent malfunction? If not, will the Hawk800/Atomahawk upgrades solve whatever problem it does have?


Any advice would be greatly appreciated.


Thanks for reading.

Re: [korgpolyex] Broken EX800?

2015-10-15 by Daniel Forró

If there's a backup battery in your EX800, just change it for new one, and transmit to the instrument SysEx or MIDI file with factory or other programs to get instrument back into proper service.

Concerning sawtooth wave, there's nothing like this in 800 series. It's only its approximation simulated by stepped waveform created by balanced mix of four  square waves. To get it you have to switch on all four stops - 16', 8', 4' and 2'. See manual page 13. Sometimes it's good to read manuals :-)

Daniel Forro


On Oct 15, 2015, at 3:02 PM, slushprodukt@... [korgpolyex] wrote:

I bought an EX800 on eBay a month ago. After it arrived, I wrote a computer program to control it over USB MIDI. I was able to trigger notes, both on and off, although I never managed to modulate the VCF (the manual says this is option 3). Anyway, a few days later I was experimenting with my software and suddenly, for no apparent reason, the EX800 seemed to crash. It made a crazy sound which I could only stop by switching the synth off.

When I switched it back on, I realised that all the "programs" had been scrambled. Going through the parameters, many of them are now nonsensical (eg. a value of 4 when it should be either 0 or 1). Most of the patches now sound exactly the same: noise, no DCO, with some fast MG filtering.

Much more importantly... The synth is no longer capable of producing a sawtooth wave. It just sounds exactly the same as the square wave.

It's strange, but I guess an accident like this is to be expected with a 31 year-old synth.

This is my first time using an EX800. I have no experience with it or the Poly800. Has anyone seen problems like this before?

I was going to buy the Hawk800 and Atomahawk kits anyway, but now I'm wondering two things. Does this EX800 have a permanent malfunction? If not, will the Hawk800/Atomahawk upgrades solve whatever problem it does have?

Any advice would be greatly appreciated.


Re: [korgpolyex] Broken EX800?

2015-10-15 by Michael Hawkins

You most likely sent too much MIDI too fast and caused the EX-800 to overwrite the patch memory due to an uncontrolled stack overflow.

The result is that the patch memory is scrambled, and since the original software does no parameter value checking, it won't generate sounds properly until you reset the entire patch memory back to valid values.

The best way to do that would be to get the original EX-800 sysex dump and send it to your EX-800 (make sure both program and seq enable switches are set to enable). Then power off and back on.

/Mike

From: "slushprodukt@... [korgpolyex]" <korgpolyex@yahoogroups.com>
To: korgpolyex@yahoogroups.com
Sent: Thursday, October 15, 2015 2:02 AM
Subject: [korgpolyex] Broken EX800?

 
Hi,

I'm hoping people will be able to advise me about the state of my EX800 and the likely chances of getting it back into working order.

I bought an EX800 on eBay a month ago. After it arrived, I wrote a computer program to control it over USB MIDI. I was able to trigger notes, both on and off, although I never managed to modulate the VCF (the manual says this is option 3). Anyway, a few days later I was experimenting with my software and suddenly, for no apparent reason, the EX800 seemed to crash. It made a crazy sound which I could only stop by switching the synth off.

When I switched it back on, I realised that all the "programs" had been scrambled. Going through the parameters, many of them are now nonsensical (eg. a value of 4 when it should be either 0 or 1). Most of the patches now sound exactly the same: noise, no DCO, with some fast MG filtering.

Much more importantly... The synth is no longer capable of producing a sawtooth wave. It just sounds exactly the same as the square wave.

It's strange, but I guess an accident like this is to be expected with a 31 year-old synth.

This is my first time using an EX800. I have no experience with it or the Poly800. Has anyone seen problems like this before?

I was going to buy the Hawk800 and Atomahawk kits anyway, but now I'm wondering two things. Does this EX800 have a permanent malfunction? If not, will the Hawk800/Atomahawk upgrades solve whatever problem it does have?

Any advice would be greatly appreciated.

Thanks for reading.


Re: [korgpolyex] Broken EX800?

2015-10-16 by Daniel Forró

Haven't you read my message? I have written about necessity to load SysEx and explained about sawtooth.

Daniel Forro


On Oct 16, 2015, at 3:07 PM, slushprodukt@... [korgpolyex] wrote:



Thanks Mike.

"the original EX-800 sysex dump"
Would that be the file "EX800.syx" file listed below?
https://groups.yahoo.com/neo/groups/korgpolyex/files/2%29%20EX-800/Patches%20and%20patch%20dumps/

I do realise that the patches have been scrambled. What I wonder is why the saw wave isn't being generated. Could that be due to incorrect parameters in a patch?

Re: [korgpolyex] Broken EX800?

2015-10-16 by Michael Hawkins

When the patch data is scrambled, many functions won't work correctly including sawtooth waveform selection.

Yes, that link to the EX800.syx factory default sysex.

/Mike

From: "slushprodukt@... [korgpolyex]" <korgpolyex@yahoogroups.com>
To: korgpolyex@yahoogroups.com
Sent: Friday, October 16, 2015 2:07 AM
Subject: Re: [korgpolyex] Broken EX800?

 
Thanks Mike.

"the original EX-800 sysex dump"
Would that be the file "EX800.syx" file listed below?
https://groups.yahoo.com/neo/groups/korgpolyex/files/2%29%20EX-800/Patches%20and%20patch%20dumps/

I do realise that the patches have been scrambled. What I wonder is why the saw wave isn't being generated. Could that be due to incorrect parameters in a patch?
 



Re: [korgpolyex] Broken EX800?

2015-10-17 by slushprodukt@...

Yes, thank you. I've been trying to load the SysEx file using MIDI-OX - no luck so far!

Re: [korgpolyex] Broken EX800?

2015-10-17 by slushprodukt@...

Thanks. I'm sorry to ask an obvious question, but which tool should I use to send the Sysex dump to the EX800? I have tried MIDI-OX, having switched both switches to "ENABLE", and nothing happens.

Re: [korgpolyex] Broken EX800?

2015-10-18 by Michael Hawkins

After you send the sysex message, trying changing patches to see if the patches have been loaded into patch memory. The patch that is running at the time that you send the sysex won't update until you do a program/patch change.

/Mike

From: "slushprodukt@... [korgpolyex]" <korgpolyex@yahoogroups.com>
To: korgpolyex@yahoogroups.com
Sent: Saturday, October 17, 2015 12:01 AM
Subject: Re: [korgpolyex] Broken EX800?

 
Thanks. I'm sorry to ask an obvious question, but which tool should I use to send the Sysex dump to the EX800? I have tried MIDI-OX, having switched both switches to "ENABLE", and nothing happens.