Great video Don! You've officially scared me enough with the state of those input caps to bump my DP/4 way up my priority list to pull from my rack and do a full recap! Would also love to check out your patches for the unit if you are open to selling the data.
Cool video! I had a DP4+ on the table lately as well. It was contaminated with electrolyt as well. I had to remove complete groups of smd parts. All the input diodes, but also the resistors ect. ..actually everything looking suspicious. Gu everywhere underneath the parts. But instead to replace them with new parts, I just cleaned them up and resoldered them. The unit works great again! If your unit looks bad like the one in the video, cleaning all parts and underneath in the contaminated area is highly recommended! For all people doing this kind of work I recommend a soldering iron that looks like tweezers.. A kind of double top iron. I have one by Ersa. You can remove these SMD parts very fast as you can heat up both sides of the parts at once. That also helps on the diodes to get them off quickly without destroying them. I was also able to remove the Op Amps from the board in the input area very easily to clean underneath. My general recommendation if you buy this unit. Let it be recapped as soon as possible if it has not been done yet. Even if the unit works perfectly. If you‘re lucky, the caps have not started leaking. Then it‘s a fast and easy job (with the right tools as you just have to exchange the electrolytic caps 😉) Ps: I need to get me one of these fiberglass pens 👌🏻
wow I have received a DP4+ that looks in perfect condition, like new about a month ago, I have tried it a few times so far and everything seems to work perfectly, I only have the "low battery" message but everything works fine, I am in love with this processor, I hope it's easy to change the battery, great technical work and excellent sounds as always master DS, greetings!
If it‘s in great shape, be glad for it! If it had not been recapped yet, let it be done as soon as possible.. If you don‘t see any damage and maybe there is none, if them caps start to leak it‘s much much more work to do then when you let it recap befor they start to leak. Just to exchange the caps is fast done. But to clean the leakage spread the tech might to remove other parts and then it gets very cost intense.
@@markusglammer2941 thank you very much Markus for the warning, at some point I will check it, yes, I received it the same as new (superficially) it seems unused, with its box and manuals, but I don't know how the interior is, thanks friend!
So is that you Don, doing the resuscitation work on that unit? Brilliant work, inspiring reason to pull out the iron, desoldering tool, microscope even...
Don: valuable video! So a DP4+ (judging by the marked chips). Mine (purchased for about €300 15 years or so ago, either had (and I didn't notice at first?), or it developed an offensive acoustic buzzing from the PSU (failed epoxy?), a stethoscope showed its max right at the transformer. The transformer bore a metal attachment, like a clip, connected by one or two screws to the transformer itself and to the top of DP4+'s metal casing, seemingly physically "stabilizing" the transformer. Couldn't figure out its function, didn't appear electrical, shielding, or earth/ground-related, so I removed it. I hadn't used the DP4+ nearly ever due to the buzzing, which now disappeared, all DP4+ functions otherwise normal. Regarding one function of that clip: it effectively transmitted the "buzzing" from the transformer to the top of the metal casing which then acted as a primitive speaker (think "telephones" made of 2 tin cans and string). Put some effort at the time I removed the "clip" to carefully examine what could be seen of the boards. Saw no damage at all, though obviously you found a lot of damage after you had removed components. I read (no longer sure where) at that time a year ago that all the SMD electrolytics should be replaced, and any electrolyte-damage repaired. Looked for and purchased (from a musicman on ebay) a kit with caps, some voltage regulators etc, but haven’t gotten around to it. Maybe I should get to it sooner rather than later! [Edit 2 mo later: have re-examined that "complete kit" I purchased on ebay - it contains a very small handful of components, nowhere near the number of caps (and diodes) you replaced.] PS: Write me up (and PM me!) when you’d like to sell your DP4+ patches! PPS! version 2.25 roms: where do I sign up?! Mine are 2.05... [Edit 2 mo later: afaics there is no later rom than 2.05...] A last couple of questions Don: do you have a complete list of the parts you ultimately replaced? Did you replace every single "canned" electrolytic cap? Which diodes to replace and which not? Did you replace any voltage regulators? Finally: was the LCD replacement a drop-in-repair or was any customization required to get it working? Cheers mate, and congratulations on this stellar achievement of yours, a great help to all of us! exdeecee/m
Great work and nice video! Do you have any experience repairing ASR-10 keyboards? Any tips on what needs top be repaired first? As a preventive solution i mean.
You are a masochist! :) By the way, a desoldering station, a more suitable soldering iron would have helped, but definitely nice job. What brand/type of built-in capacitors? I see that these are not Nichicon KA, FG or ELNA, etc. Audio grade where they should be? (audio signal path)
Caution: This board will be damaged if hot air is used. It was a bit cheaply made. I know for a fact, as I've damaged my DP4+ that way and had to rebuild half a dozen pads, traces, etc. So I've learned my lesson there and was able to repair this one the proper way. Capacitors: I installed only high end stuff. PSU: Panasonic 105ºC/5,000h, Nichicon 105ºC/10,000h. Other boards: Panasonic 85ºC/ 105ºC 5,000h
@@DonSolaris Yes, hot air is a bitter experience... I was thinking of something a bit different, I use several stations with different hole sizes and safe temperatures to heat up the PCB ,only for the time and temperature what required. This is good to know that this series is particularly sensitive, thanks for the info! Very nice work! Congratulations! Caps. If it didn't interfere with the sound, good. Unfortunately, they can be very involved. I once re-conditioned a Korg Mini Pops 7 with the best available, 8000h or +, min 105C°, etc., and A/B matched it with an original, well... It sounded catastrophic :) Anyway, my best experiences are with the Nichicons audio series and less often with ELNA.
@@DonSolarisheck. Maybe this was my problem. I used hot air… I’ve triple checked the connections (only replaced caps) and it works worse now. Sigh. Back to the drawing board. Sigh
@@DonSolaris Wow! Great Job on this Machine. Where to Download the latest binaries (OS 2.25) @50:14 for the dp4+ ????? Can you Help me pls, i'm lost. Can you also Help for a partlist, for example the new Display!?
@@VideoJunkXXL The owner of this unit bought the OS from someone else (I think eBay) and asked me to write it into EPROMS. I don't have the unit anymore. It was returned to the owner 6 months ago. Cheers!
Unfortunately I don't have EPS but I have ASR-10 and yes, those effects are same league, but ASR can go 44kHz, so better. Still DP4 has 3 more DSP units, so hard to cover all of the effects.
Great video Don! You've officially scared me enough with the state of those input caps to bump my DP/4 way up my priority list to pull from my rack and do a full recap!
Would also love to check out your patches for the unit if you are open to selling the data.
Dp4 doesn't use smds just dp4+
Cool video! I had a DP4+ on the table lately as well. It was contaminated with electrolyt as well. I had to remove complete groups of smd parts. All the input diodes, but also the resistors ect. ..actually everything looking suspicious. Gu everywhere underneath the parts. But instead to replace them with new parts, I just cleaned them up and resoldered them. The unit works great again! If your unit looks bad like the one in the video, cleaning all parts and underneath in the contaminated area is highly recommended!
For all people doing this kind of work I recommend a soldering iron that looks like tweezers.. A kind of double top iron. I have one by Ersa. You can remove these SMD parts very fast as you can heat up both sides of the parts at once. That also helps on the diodes to get them off quickly without destroying them. I was also able to remove the Op Amps from the board in the input area very easily to clean underneath.
My general recommendation if you buy this unit. Let it be recapped as soon as possible if it has not been done yet. Even if the unit works perfectly.
If you‘re lucky, the caps have not started leaking. Then it‘s a fast and easy job (with the right tools as you just have to exchange the electrolytic caps 😉)
Ps: I need to get me one of these fiberglass pens 👌🏻
Wow! Great work! Thank goodness the DP4 (non plus) is through hole
Awesome. Nice job. Great sounds. Thanks for sharing; useful info :D
wow I have received a DP4+ that looks in perfect condition, like new about a month ago, I have tried it a few times so far and everything seems to work perfectly, I only have the "low battery" message but everything works fine, I am in love with this processor, I hope it's easy to change the battery, great technical work and excellent sounds as always master DS, greetings!
If it‘s in great shape, be glad for it! If it had not been recapped yet, let it be done as soon as possible.. If you don‘t see any damage and maybe there is none, if them caps start to leak it‘s much much more work to do then when you let it recap befor they start to leak. Just to exchange the caps is fast done. But to clean the leakage spread the tech might to remove other parts and then it gets very cost intense.
@@markusglammer2941 thank you very much Markus for the warning, at some point I will check it, yes, I received it the same as new (superficially) it seems unused, with its box and manuals, but I don't know how the interior is, thanks friend!
So is that you Don, doing the resuscitation work on that unit? Brilliant work, inspiring reason to pull out the iron, desoldering tool, microscope even...
Epic. Very nice work!
Don: valuable video!
So a DP4+ (judging by the marked chips). Mine (purchased for about €300 15 years or so ago, either had (and I didn't notice at first?), or it developed an offensive acoustic buzzing from the PSU (failed epoxy?), a stethoscope showed its max right at the transformer. The transformer bore a metal attachment, like a clip, connected by one or two screws to the transformer itself and to the top of DP4+'s metal casing, seemingly physically "stabilizing" the transformer. Couldn't figure out its function, didn't appear electrical, shielding, or earth/ground-related, so I removed it. I hadn't used the DP4+ nearly ever due to the buzzing, which now disappeared, all DP4+ functions otherwise normal. Regarding one function of that clip: it effectively transmitted the "buzzing" from the transformer to the top of the metal casing which then acted as a primitive speaker (think "telephones" made of 2 tin cans and string).
Put some effort at the time I removed the "clip" to carefully examine what could be seen of the boards. Saw no damage at all, though obviously you found a lot of damage after you had removed components. I read (no longer sure where) at that time a year ago that all the SMD electrolytics should be replaced, and any electrolyte-damage repaired. Looked for and purchased (from a musicman on ebay) a kit with caps, some voltage regulators etc, but haven’t gotten around to it. Maybe I should get to it sooner rather than later!
[Edit 2 mo later: have re-examined that "complete kit" I purchased on ebay - it contains a very small handful of components, nowhere near the number of caps (and diodes) you replaced.]
PS: Write me up (and PM me!) when you’d like to sell your DP4+ patches!
PPS! version 2.25 roms: where do I sign up?! Mine are 2.05... [Edit 2 mo later: afaics there is no later rom than 2.05...]
A last couple of questions Don: do you have a complete list of the parts you ultimately replaced? Did you replace every single "canned" electrolytic cap? Which diodes to replace and which not? Did you replace any voltage regulators? Finally: was the LCD replacement a drop-in-repair or was any customization required to get it working?
Cheers mate, and congratulations on this stellar achievement of yours, a great help to all of us!
exdeecee/m
Hello, do you happen to know the calibration procedure for the DC offset and the distortion please ?
Great job, Don
Crumbs! I'd better check on and give mine some TLC soon.. great vid Don
Nicely done. Cheers! S
Amazing and inspiring!!
How could you tell the op amps were damaged?
Thank you for this video. Could you please share what display you used for replacement?
Great work and nice video! Do you have any experience repairing ASR-10 keyboards? Any tips on what needs top be repaired first? As a preventive solution i mean.
And yet, people ask well over 1K for these things WITH OG CAPS!! Crazy.
Impressive
Hello. Just one question please. Where do you find your new display screen please?
Thanks 🙏🙏🙂
You are a masochist! :) By the way, a desoldering station, a more suitable soldering iron would have helped, but definitely nice job. What brand/type of built-in capacitors? I see that these are not Nichicon KA, FG or ELNA, etc. Audio grade where they should be? (audio signal path)
Caution: This board will be damaged if hot air is used. It was a bit cheaply made. I know for a fact, as I've damaged my DP4+ that way and had to rebuild half a dozen pads, traces, etc. So I've learned my lesson there and was able to repair this one the proper way. Capacitors: I installed only high end stuff. PSU: Panasonic 105ºC/5,000h, Nichicon 105ºC/10,000h. Other boards: Panasonic 85ºC/ 105ºC 5,000h
@@DonSolaris Yes, hot air is a bitter experience... I was thinking of something a bit different, I use several stations with different hole sizes and safe temperatures to heat up the PCB ,only for the time and temperature what required. This is good to know that this series is particularly sensitive, thanks for the info! Very nice work! Congratulations!
Caps. If it didn't interfere with the sound, good. Unfortunately, they can be very involved. I once re-conditioned a Korg Mini Pops 7 with the best available, 8000h or +, min 105C°, etc., and A/B matched it with an original, well... It sounded catastrophic :) Anyway, my best experiences are with the Nichicons audio series and less often with ELNA.
@@DonSolarisheck. Maybe this was my problem. I used hot air… I’ve triple checked the connections (only replaced caps) and it works worse now. Sigh. Back to the drawing board. Sigh
Someone must have replaced the original yellow green display for a blue one 😬.. The new yellow one looks awesome!
hey nice work! what would a repair like this cost? regards
epic
Hi Don! Great video ^_^ Quick question, what display did you use? Been trying to find a suitable replacement but no luck so far...
How long did this restoration take you .
Ive got a dp4 and dont see any smds. Phew
Hi, what are good modern alternatives for the opamps and diodes? I have the same issue with my DP4+
Mogu li dobiti adresu ovog servisa.
Why not use surface mount caps? Would have taken less time to replace
Good question! Customer wanted premium caps that will last for decades. We can see how these SMD caps ended.
@@DonSolaris
Wow! Great Job on this Machine.
Where to Download the latest binaries (OS 2.25) @50:14 for the dp4+ ????? Can you Help me pls, i'm lost.
Can you also Help for a partlist, for example the new Display!?
@@VideoJunkXXL It's a typo in the video. It's 2.05. :)
@@DonSolaris Oh okay. 😁
Can you pls Help or Send me the 2.05 OS binaries!? 😊
Can't find any source
@@VideoJunkXXL The owner of this unit bought the OS from someone else (I think eBay) and asked me to write it into EPROMS. I don't have the unit anymore. It was returned to the owner 6 months ago. Cheers!
Can EPS 16+ with Wave Boy effects sound close to DP?
Unfortunately I don't have EPS but I have ASR-10 and yes, those effects are same league, but ASR can go 44kHz, so better. Still DP4 has 3 more DSP units, so hard to cover all of the effects.
well look's like its got a better power supply than the DP/2 which are no longer available .......
this "soldering" is awfully atrocious. keep up the good work for our sound banks and effects though.