Ensoniq Mr-76 vintage keyboard static

[Leo L]

Hi, I have an Ensoniq Mr-76 vintage keyboard and recently I´ve been hearing some static-like noise through my PA system, at first I thought it was a fault in the speaker but then I tried other keyboards and the sound came out fine so I decided to take my keyboard to a technician and he told me that he coudn´t repair because the noise came from the microprocessor, what I want to know is, do any of you know if this can be repaired? or if in order to replace the microprocessor I should get one exactly the same (I mean same make, same model) or if there are other options. Please give as much info as you can. Thanks a lot !!!

 

[happyrat1]

First of all I wonder what that "technician" was smoking.

I seriously doubt that the CPU is generating static in the audio path.

It may, however be resistance noise from a cracked or loose solder joint somewhere on the board or in the connectors. Or it could even be a dirty and noisy potentiometer that needs a squirt of contact cleaner or replacement. Also, given the age of the keyboard I would suggest replacing the electrolytic capacitors before they start to fail.

I'd suggest taking it to a different technician who actually knows his stuff to trace the noise along the audio patch and do a proper repair.

Gary

 

[Leo L]

First of all I wonder what that "technician" was smoking.

I seriously doubt that the CPU is generating static in the audio path.

It may, however be resistance noise from a cracked or loose solder joint somewhere on the board or in the connectors. Or it could even be a dirty and noisy potentiometer that needs a squirt of contact cleaner or replacement. Also, given the age of the keyboard I would suggest replacing the electrolytic capacitors before they start to fail.

I'd suggest taking it to a different technician who actually knows his stuff to trace the noise along the audio patch and do a proper repair.

Gary

Thanks a lot Gary

 

[MidiMike]

I would go with what Gary has said. I have two Ensoniq keyboards and they have done quite well, over the years. I got them both brand new, in 1990. the metal cases are a plus. Like Gary says, it could be a solder point on a board. One of my keyboards had a bad connection at the midi plug and it was causing all kinds of strange things to happen. I thought the keyboard was crashing.
I noticed it was worse when I played harder on the keyboard so thought maybe it was a loose connection. Looking at all of my connections, I found the midi socket had a solder point that had come loose. Just a bit of solder and I was back in business.

I know your post is from a couple of years ago, so I hope your problem has been fixed. It not, I hope this has given you something else to check out.

 

[delaware dave]

All of the above. I lived 'close' to Malvern Pa where their facility was back in late 80's and owned the VFX. the keyboard would freeze up during a gig but worked great when sent to the factory for troubleshooting. Ensoniq sent an in-house tech (Dennie Edwards) to one of my shows and the keyboard froze up with the dreaded '144 calibration error'. Turns out they had changed to lead free solder flux during the VFX manufacturing it is was creating havoc. The running joke at Ensoniq was that you were not allowed to use the word "VFX" within the 4 walls of the building. The MR was produced not long after the VFX introduction. I'll put $20 on the solder being an issue.

see this link then go to the 'reliability' chapter: https://en.m.wikipedia.org/wiki/Ensoniq_VFX

 

[peedenmark7]

Old topic that I'm sure the issue has been rectified or the 76 has been sold, but I'm having the same issue.

My issue is after about 5-10 mins of warm up a crackling sound like random static or a small lighting storm begins in the audio path, it ceases after about 2 mins, and the synth then works fine again .

Shipping an MR76 across country is expensive, so I went back and forth with an Ensoniq repairman out east. He asked that I send the jack board to him, and he supposedly replaced 8-9 aluminum can caps,
got it back and the issue though not as bad persists. He now suggests replacing the PSU board due to the way everything is laid out can be part of the issue . True?.
I got it cheap, but there are some clacky keys in the middle C range, and really dont want to put any more money into it unless audio issue resolved.

I thought about getting an MR61 , I use my 76 for drums only, during demo work as I'm not a fan of piano weighted keys..

Maybe a Roland R8 is in the near future.

 

[STEALTHDEBURGO]

All of the above. I lived 'close' to Malvern Pa where their facility was back in late 80's and owned the VFX. the keyboard would freeze up during a gig but worked great when sent to the factory for troubleshooting. Ensoniq sent an in-house tech (Dennie Edwards) to one of my shows and the keyboard froze up with the dreaded '144 calibration error'. Turns out they had changed to lead free solder flux during the VFX manufacturing it is was creating havoc. The running joke at Ensoniq was that you were not allowed to use the word "VFX" within the 4 walls of the building. The MR was produced not long after the VFX introduction. I'll put $20 on the solder being an issue.

see this link then go to the 'reliability' chapter: https://en.m.wikipedia.org/wiki/Ensoniq_VFX

Buddy, the vfx came out

 

[STEALTHDEBURGO]

All of the above. I lived 'close' to Malvern Pa where their facility was back in late 80's and owned the VFX. the keyboard would freeze up during a gig but worked great when sent to the factory for troubleshooting. Ensoniq sent an in-house tech (Dennie Edwards) to one of my shows and the keyboard froze up with the dreaded '144 calibration error'. Turns out they had changed to lead free solder flux during the VFX manufacturing it is was creating havoc. The running joke at Ensoniq was that you were not allowed to use the word "VFX" within the 4 walls of the building. The MR was produced not long after the VFX introduction. I'll put $20 on the solder being an issue.

see this link then go to the 'reliability' chapter: https://en.m.wikipedia.org/wiki/Ensoniq_VFX

The VFR came out in 89, then the

Hi, I have an Ensoniq Mr-76 vintage keyboard and recently I´ve been hearing some static-like noise through my PA system, at first I thought it was a fault in the speaker but then I tried other keyboards and the sound came out fine so I decided to take my keyboard to a technician and he told me that he coudn´t repair because the noise came from the microprocessor, what I want to know is, do any of you know if this can be repaired? or if in order to replace the microprocessor I should get one exactly the same (I mean same make, same model) or if there are other options. Please give as much info as you can. Thanks a lot !!!

If you got static - without any input , then it's probably more to do with the analog section, that generation had the option of sensing if the connection was unbalanced or balanced and would automatically switch. An opamp maybe on its way out. If the static sound when triggering a note, then it's more likely in the memory, perhaps a bad soldering joint which on those are surface mounted. You need a special hot air soldering machine. Also check the ribbon connections. Not sure about electrolytic caps on the mr 61. The mr racks don't have any in their power supply . I have both but the keyboard is at my buddies place. It might has some being they have a floppy drive and larger display so it might have. If it does, replace it . A dieing cap can take the regulator out and potentially other components . Try tapping on the electrolytic to see if changes the static, but do it gently.
Unfortunately I don't think I have seen a service manual or schematics for the unit. Thesonic.com does do repairs, used to work there in some sort of repair or trouble shooting capacity. He has a list of parts available, plus will exchange key beds, an issue that does creep up more that not. If you have any expansion rom cards, try removing them and see. They could have a bad connection that will effect playback. Just remember that if you want to remove a ribbon cable, use a pry tool only and don't pull on the cable directly. Btw someone mentioned about the vfx being somewhat similar, the vfx and Mr are three generations apart. Absolutely nothing in common other than the manufacturer.
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