Looking for Ensoniq DP Pro Service Manual / Schematics

[58Glammer]

I´m about to service a Ensoniq DP Pro FX unit and I´m looking for a service manual incl. schematics.

Actually I got three units. One is missing parts and the other two I just want to recap.

It has SMD caps installed and the model is from 1996.. so it might be healthy for it to recap before the caps start leaking.

I´m thinking of replacing the SMD electrolytic caps with normal caps. There is enough space. The tantal caps I will recap with the same type.

I will also replace the old display with a blue LED display. I already found one at buydisplay.com (24x2 letters) . (about 5 $US)
(Edit: A tip: If your display still works, just leave it in. If not, try to get one with dark background, as the blue one will kill your eyes. I changed the display again and built in a black one with white characters. The viewingangle of the blue one also wasn‘t as good)

I think, as I have a working unit , I can compare the components especially for the missing parts. But it would be great to have the schematics and the service manual for it, just to be sure.

Thanks
Markus

 

[58Glammer]

Update: I replaced the missing caps on the motherboard at the 5 V output rail from the PSU.
But without the schematics I can´t validate the values of the two smd fuses (?) (FB 19, FB 20) installed parallel at the 5 V input rail.
I took the parts from the working unit to check, if this unit also works when the missing parts are replaced. And it works!

Is there a way to get the values of the two parts without the schematics?
The PSU displays 2A on the 5V output. And what kind of part is this?

 

[Khron]

"FB" is more often the designator for "Ferrite Bead"; fuses are rather designated with just "F".

https://en.wikipedia.org/wiki/Ferrite_bead
And yes, those definitely do look like ferrite beads rather than fuses. The only time I've seen SMD fuses in parallel was on the internal circuit board of a Makita tool battery, a pair of 50A jobs.

 

[58Glammer]

"FB" is more often the designator for "Ferrite Bead"; fuses are rather designated with just "F".

https://en.wikipedia.org/wiki/Ferrite_bead
And yes, those definitely do look like ferrite beads rather than fuses. The only time I've seen SMD fuses in parallel was on the internal circuit board of a Makita tool battery, a pair of 50A jobs.

Ah, thanks a lot! That‘s it. . So is there anything I need to take care (specs) when I’m looking for these FBs beside the same size to fit in place?
The size of them is 8 mm x 5 mm x 3 mm
I found parts at RS from Wurth in that size. There were no other ones with other specs available, so I think these are ok.
Each one can take about 5 A. So if these had been fuses, these def had have done the wrong job in a 5 V dc rail ..

 

[58Glammer]

Finally I received all parts (including the missing ferrite beads FB 19/20) I needed to recap the 2 Units.
I also recapped the Powersupplies.
All went out pretty well.
I changed my decision to replace the SMD caps with normal caps and replaced just the bigger smd 220/16v with normal 220/25v (voltage value a bit higher) ones.
If someone is going to recap a SMD board, I recommend the right tools.
I have a iron for my solderingstation that is like tweezers.. and you can desolder both contacts at ones.. otherwise these smd caps are hard to get off the board. Especially if you got plenty of them and more units .
So this tool was pretty handy for that to get it done quickly.

I tried the two DP Pros out at the studio and they sound great!

 

[damien]

Did you get your hand on the service manual in the end? I don't know if it ever existed. My DP Pro has a little noise on the R chanel, I need to investigate that later this winter. Thanks!

 

[58Glammer]

Did you get your hand on the service manual in the end? I don't know if it ever existed. My DP Pro has a little noise on the R chanel, I need to investigate that later this winter. Thanks!

Hi Damien,
is yours already recapped?
Unfortunately I could not find the Servicemanual for the DP Pro..
After recapping and adding the missing FB the units (I had 3) worked pretty well. Also exchanged the display through a blue LED one. Afterwards I would not recommend that as it is (even when dimmed) much tooo bright. My tip, if the old display still workes, just leave it in. Or better get a OLED
About the noise... two tips..
1. Check the PCB near the audio ins and outs for solderingblobs on the surface where the parts are soldered to..
On two of my three there was a big solderblob. I guess they oversaw that at the quality check as it‘s a bit hidden under the frame.
2. there are pods for adjusting the digital distortion level for each channel. If you put a very low audio signal through a channel, you can hear if its adjusted right. If it‘s sounds clear, it‘s adjusted fine.
If it sounds distorted, you can adjust the pods till the signal sounds clear.
(same on the DP4+)
But the audiosignal feed to the input has to be very low.
There are not many of those pods and as I remember the function of the pods is written onto the PCB ..
Good luck on finding the fault and good luck on the hunt for the service manual!

 

[beyond the gallbladder!]

do you happen to know the part name of the connector at J1301 + J1302? One of mine popped off-- it goes to the front panel controls. Just no idea what to order/ what size it is. Thanks!

 

[58Glammer]

do you happen to know the part name of the connector at J1301 + J1302? One of mine popped off-- it goes to the front panel controls. Just no idea what to order/ what size it is. Thanks!

Could you take a picture of the connector? I can‘t tell you what part to order as I don‘t know. But maybe someone else can?

 

[beyond the gallbladder!]

Thanks! just saw your reply. Will open it up and get a pic tonight or tomorrow.

 

[beyond the gallbladder!]

ok, so it looks like the same 20-pin as J1301, but it's labelled "JK" / "KEYPAD"
Thank you so much!!

 

[damien]

Hi Damien,
is yours already recapped?

Hi, The noise on mine was gone for a while, but it's back. I'll check inside, the capacitors on the main board may be faulty, I suspect one of those out of specs or a cold solder joint on the input path, because the noise is "processed" through the DSP. Nothing crazy though.

I have issues with mine while trying to sync it to my DAW with the settings "Clock" > MIDI, it's like the tempo is 10000 BPM, but when switched back to internal, it's back to the 120BPM speed (internal BPM). Can you please check on yours ? I have firmware 1.10
You'll notice, all the pictures of those DP Pro online have number code 100 to 150, I think they never produced more than 200-300 of those units before Ensoniq got merged to Soundblaster Creative Labs. It's a wonderful FX, but released in the rush in their beta version with many bugs, unfinished MIDI implementation.

Let me know Thanks in advance
Damien

 

[58Glammer]

Hi, The noise on mine was gone for a while, but it's back. I'll check inside, the capacitors on the main board may be faulty, I suspect one of those out of specs or a cold solder joint on the input path, because the noise is "processed" through the DSP. Nothing crazy though.

I have issues with mine while trying to sync it to my DAW with the settings "Clock" > MIDI, it's like the tempo is 10000 BPM, but when switched back to internal, it's back to the 120BPM speed (internal BPM). Can you please check on yours ? I have firmware 1.10
You'll notice, all the pictures of those DP Pro online have number code 100 to 150, I think they never produced more than 200-300 of those units before Ensoniq got merged to Soundblaster Creative Labs. It's a wonderful FX, but released in the rush in their beta version with many bugs, unfinished MIDI implementation.

Let me know Thanks in advance
Damien

I would suggest to replace all electrolytic caps first and then check again.
Don‘t look for one faulty cap and just replace that. If it‘s not recapped yet, recap ALL the electrolytic caps.
If these caps start to leak, it‘s more problematic than just to recap the unit.
And yes, the DP Pro just feels put out in a rush..

 

[58Glammer]

ok, so it looks like the same 20-pin as J1301, but it's labelled "JK" / "KEYPAD"
Thank you so much!!View attachment 102353View attachment 102352

Yes, looks like the same connector. I think, one of these came off on one of my units as well, but I was able to resolder it. Just search for SMD flat cable connectors 20 pin and compare it with J1301

BTW: Re-check the polarisation of ALL your caps you have exchanged!
I saw on the second picture that C1312 and C1313 are soldered in the wrong direction! The black mark on a electrolytic cap is „-„ and on the PCB is a „+“ mark.
If you also exchanged the tantal caps that also have a polarisation, check the polarisation as well. Especially because on these the black mark is „+“ . The polarisation of the electrolytic and the tantal caps always have to match the polarity written on the PCB

 

[damien]

Yes, looks like the same connector. I think, one of these came off on one of my units as well, but I was able to resolder it. Just search for SMD flat cable connectors 20 pin and compare it with J1301

BTW: Re-check the polarisation of ALL your caps you have exchanged!
I saw on the second picture that C1312 and C1313 are soldered in the wrong direction! The black mark on a electrolytic cap is „-„ and on the PCB is a „+“ mark.
If you also exchanged the tantal caps that also have a polarisation, check the polarisation as well. Especially because on these the black mark is „+“ . The polarisation of the electrolytic and the tantal caps always have to match the polarity written on the PCB

Good to know!
I'll replace all the panasonic SMD capacitors there are not that much on the main board, there's like 25-30. I have good hope it's coming from them, the DP pro is almost from the capacitor plague era, they are 30 years old, so it makes sense to replace them anyway.




I'll see if it's working after that, and also spray with contact cleaner the volume A5K pot. Input/Output sockets are also oxydized so contact cleaner should also help in there.

Please confirm those are the capacitors you were talking about
And thank you for letting me know that the midi clock sync is not working because of a buggy firmware, I'm relieved.

Damien

 

[58Glammer]

Good to know!
I'll replace all the panasonic SMD capacitors there are not that much on the main board, there's like 25-30. I have good hope it's coming from them, the DP pro is almost from the capacitor plague era, they are 30 years old, so it makes sense to replace them anyway.

View attachment 105226


I'll see if it's working after that, and also spray with contact cleaner the volume A5K pot. Input/Output sockets are also oxydized so contact cleaner should also help in there.

Please confirm those are the capacitors you were talking about
And thank you for letting me know that the midi clock sync is not working because of a buggy firmware, I'm relieved.

Damien

Actually, I can‘t tell you if the midi sync doesn‘t work. Never used that option. But I was looking into the system menue yesterday and when I switched to external midi sync, nothing happend. The tempo did not flip to 1000 bpm or another tempo. It stood the same as before.
But I have no midi connected with my effect units. I never use that option. So I can‘t really tell you if there is a bug here.
And yes, the marked ones are the electrolytic caps.. All of them on the board.. About 37 all in all.

 

[damien]

Thanks mate for the info. I'll keep you posted about the repair in this thread when I'll get the capacitors.

 

[58Glammer]

Thanks mate for the info. I'll keep you posted about the repair in this thread when I'll get the capacitors.

I hope you have the right solderingtools to get them off the PCB. If not, you can destroy more than you repair. Have you worked with SMD parts before?

 

[damien]

I hope you have the right solderingtools to get them off the PCB. If not, you can destroy more than you repair. Have you worked with SMD parts before?

Yes don't worry mate I have repaired a hundred other gears.

 

[beyond the gallbladder!]

Yes, looks like the same connector. I think, one of these came off on one of my units as well, but I was able to resolder it. Just search for SMD flat cable connectors 20 pin and compare it with J1301

BTW: Re-check the polarisation of ALL your caps you have exchanged!
I saw on the second picture that C1312 and C1313 are soldered in the wrong direction! The black mark on a electrolytic cap is „-„ and on the PCB is a „+“ mark.
If you also exchanged the tantal caps that also have a polarisation, check the polarisation as well. Especially because on these the black mark is „+“ . The polarisation of the electrolytic and the tantal caps always have to match the polarity written on the PCB

Thanks! That is weird, I haven't exchanged any caps! I purchased this unit new. The battery is the only thing that's been replaced.
I see what you're talking about, really bizarre!!