I picked one up yesterday for $200 USD and put an OLED screen in it right away lol. FYI, every DX7 I've ever worked on has enabled the portamento when it was fully reset with no battery for a while. It's an easy fix to turn off thankfully. Not a bad deal for $100. Add a little reverb and delay and it can sound pretty killer even today. Enjoy!
Not only is Dexed a 1:1 DX-7 emulation, it can also save and load DX-7 sysex data, which means you can also use it as an editor for your physical DX-7.
Pump and braid are both useful, braid is good for cleanup after suction, and another tip is use a CR123 better and the holder extended off the board (similar to how you did with the CR2032), they are the same voltage but easier to remove and add the battery and last longer. As an aside, although you might not have realised it, taking the battery off board can save the electronics from damage if the battery leaks any contents.
If I may give you an advice, place that battery holder in another spot or at least zip tie it to the wire harness that runs over it. That's because double-sided sticky tapes sometimes tend to loose their stickiness over time, especially in a warm environment like the internals of an electronic instrument. That holder has exposed metal both from the battery and the pins where the wires are soldered, and if that falls on the mainboard beneath it when the synth is turned on, that will make random shorts on the board and you're most likely gonna say goodbye to your DX-7. Not worth the risk, definitely.
There are many different "Knopfzellehalter" at for example Reichelt, that should fit close enough directly to the PCB. They do not fall off when the tape gets too warm. Especially as the metal is black and next time the sun shines, your assembly will fall onto the PCB and kill something that is not available anymore as spares. Secondly these coin cells with soldering leads are not that rare and can be bought, but I have to admit, that the two pin cells are rarer in Europe as here we usually use 3 pin coin cells for soldering, the plus has two contacts, the minus only one. But it is easy to bend or cut so it fits to the PCB. Taking into account, that it is to be changed in 10 to 15 years, I'd suggest soldering over taping it somewhere. The soundwill get better and the hum will go away if you simply replace all electrolytic capacitors. The hum suggests the caps from the power supply are becoming bad and the low audio points to the two polar 1uF/50V caps aside IC53 and the bi-polare 1uF/50V at output of IC54. We can start a discussion about if to change only tested bad caps or all at once. My way is: If one fails, the others will follow as they all lived in the same environment. And check the contacts of the external Volum control port. It is a control signal, but the plug may have some corrosion on the contacts. @Guitar3000: If you live in southern Germany and don't feel happy to replace the caps and measure everything else to be fine, get in contact with me, you can use my lab and I assist you if needed.
You're a braver man than I am! Well done for getting it working. Another way to get the DX7 sound is Korg's Opsix. It can load original DX7 sound banks, and it will automatically use the old 12 bit sine waveforms. It's not perfect - there are other RUclipsrs who have covered this in detail - but, editing FM on the Opsix is joyfully easier than on the old DX series.
And this is one of the pitfalls of those old boards with caps. It's not out of the question he might have to spend over 100 bucks in caps just for the replacement, which will make the keyboard not that much of a bargain.
I considered making one, but on second thought, it wouldn't have been much use. They were all very quiet even with the volume cranked all the way up, so they came with a lot of noise. Like I said, not all of the patches even made any sound. Others were the same pitch regardless of the key pressed, and some just sounded unpleasant. So likely, there wouldn't have been any use case for the samples. Maybe I can recreate it in some way.
So, not sure why I got recommended this, but a lot of people have brought up good points. I know this is a wall of text, but please take a few moments to read. It will save you much time and heartache. Even if you think 90% of my suggestions are trash, the 10% you do decide to do will still help you for the rest of your life and countless projects and repairs in your future. You do not "reuse" solder, you should remove old solder completely, and add fresh solder to any joints you mess with. You can get away with it somewhat if you add liquid flux on your own, but really.. why? You're already melting solder, already using a solder sucker, why would you add flux to try to reuse what's left.. instead of just soldering with solder? Doesn't make any sense. Especially not depending on the year of the equipment you're working on, where leaded solder, or lead-free solder exists. Adding leaded solder to lead-free joint can lower the melting point and increase the fluidity and lower viscosity (for the same temp), making it easier to desolder stuff and increase wetting and heat transfer, making it safer for the board. By that I mean, the wire or pin you're trying to remove, slides out of the through-plated hole without ripping a pad off either side of the PCB, versus only the side you touch with the iron melting, and you wiggling and wiggling to pull the wire out, and rip the pad off the other side. There are so many ways to mess up. But thankfully a handful of rules pretty much brings the chances down to 0%. Always add fresh solder to a joint, no matter what, it helps desolder/remove what you're trying to remove, as well as the fresh flux cleaning the area. Try to remove all the old solder completely, you might have to add fresh solder, sucker out, add solder, sucker out, until it's all gone. The same would apply to you trying to make a good joint, but in the opposite direction - getting worse every time you heat it, so don't do it. Add fresh solder, remove, clean all the solder out, then solder with fresh solder on the wire/pin/etc. Mixing leaded to lead-free helps remove components faster and with less thermal input, reducing chances of damage. But you should remove the random crap of indeterminable alloy that remains completely, before soldering with fresh solder. Add a little section of silicone or teflon tubing to the end of your soldersucker. That heating up with an iron, pulling the iron away, trying to get the tip onto the joint while shaking for 3 seconds and shit cools down, failing to sucker the solder out, and repeat over and over again is not the way to do it. Each time you heat the joint, you're causing damage. This is why you add fresh solder (and flux every time!), and failing that, you will cause the glue that holds both the pads to the PCB on both sides, but also the plated through-hole. Fresh solder/flux, lowers the temp that everything melts at, meaning the amount of time your iron is there is minimized, reducing the damage done to the PCB. Same for being able to use lower temps and still getting stuff done. Desoldering braid on it's own is useless unless it is pre-dipped in flux, and even then adding your own is best. More flux is always better. The only downside is how much cleaning you have to do afterwards. Flux is what makes soldering possible. You cannot solder without flux. As soon as metals heat up, they grow an oxide skin. Oxides are already reacted and inert, so.. trying to solder with skinned up, dry solder onto heated up and dirty pad or wire, will not happen. It just beads up and doesn't stick. Flux is an active chemical, melting it activates it. It destroys oxides and metal salts. It leaves atomically clean metal surfaces, and keeps air from contacting these surfaces while you're working with them. Because atmospheric oxygen will just.. oxide things up immediately at soldering temps. Flux destroys any crud and oxides, then protects the area and prevents the skin from growing back, and helps the solder wet and atomically bond. Soldering isn't just.. metal sticking. It's infinitely complex. On a copper wire with leaded solder and rosin flux, the surface of the copper wire actually dissolves into the solder directly, and that gradient of metal alloys causes them to bond at the atomic and molecular level. Same with tin (what coats cheap PCB's and the surface of chips). Leaded solder, after all, is typically 60/40 (or 63/37) tin/lead alloy. The point is, solders are eutectic. That means that these metals mixed together melt at a lower temperature, than either metal on it's own. 60/40 solder melts at 360f while tin melts at 450f and lead at 620f. This is why getting rid of old/mixed solder is important, before resoldering with fresh. You always clean with isopropyl alcohol. Always. Natural Rosin based flux (used in leaded solder) will undergo chemical changes over time, including becoming conductive causing weird glitches and possible circuit damage, but also slowly corrode anything it touches (i.e. the pads, joints, and pins of everything in the area). Modern "no-clean" / ROHS fluxes are much more aggressive and bad for you, but work quite well for both leaded and lead-free. You should still clean up afterwards. The 15 seconds with some rubbing alcohol and a qtip is far less work, then hours chasing down weird glitches, or your device becoming damaged beyond your ability to repair! Think about it. Adding fresh solder takes 2 seconds longer for that first heat, but 10x faster than attempting to remelt the area 5-10x with just a dry iron and causing damage. Tip on sucker lets you place it right on the joint, right up against the tip of your iron. You don't move the tip away, then struggle to get the sucker in place. You put them both there at the same time, and when things melt you push the button. Once you get what you want out, sucker out the holes or whatever, going over with some desoldering braid is useful. Gets rid of everything, giving you a perfectly clean and shiny metal surface to solder too.
Wow, some very thorough advice from someone much more experienced than me. Since I'll probably have to replace the caps, this is going to be quite useful. Thank you for taking so much of your precious time!
@@FelixPrankel Of course. I was hoping you didn't take offense, having people come in and WELL AKSHULLY can be annoying, or people just copy/pasting shit without understanding. I enjoyed your vid and look forward to your project! Also, for what it's worth, you can with caps cheat. You add fresh solder and melt one leg, then you use your finger on the other side to lean the cap in the opposite direction, then you remove iron, wait a few seconds, then melt the second leg, and push it the opposite direction, should take 2-3 times total before the cap falls out. Then you can use the solder sucker to suck the hole clean on the first try! Also, depending how many layers the PCB has, there are internal layers of copper, and the + and - are usually run on the inside, and have lots of metal to suck the heat away! Say you wiggle the cap out, and now the PCB is even, solder even on the surface, trying to get it to melt the full thickness can take a while, and if there isn't any flux it won't really melt fully. So adding a big blob of solder lets it mix with the remnants of the hole letting it melt easier. If you couldn't tell, the main thing about soldering is cleaning the tip iron and keeping it tinned, and cleaning the board/area, whether that means extra flux, or using qtip and alcohol, etc. Good luck, and again, I wasn't trying to be condescending, so I hope it wasn't taken as such
been trying to send the sysex files to mine but nothing happens, all I hear is a light click noise in my head phones whenever the volume is turned up or down, any idea what I should do? (For context I believe mine has an expansion)
bro doesn't play the guitar3000, bro IS the guitar3000 EDIT: i love dexed, i made an entire album using mostly dexed for the DX7 80s flavor. you can find it on my youtube and even spotify
You turned the DX7 switch off, and the unit turned ON. Magic.
I picked one up yesterday for $200 USD and put an OLED screen in it right away lol. FYI, every DX7 I've ever worked on has enabled the portamento when it was fully reset with no battery for a while. It's an easy fix to turn off thankfully. Not a bad deal for $100. Add a little reverb and delay and it can sound pretty killer even today. Enjoy!
Not only is Dexed a 1:1 DX-7 emulation, it can also save and load DX-7 sysex data, which means you can also use it as an editor for your physical DX-7.
Pump and braid are both useful, braid is good for cleanup after suction, and another tip is use a CR123 better and the holder extended off the board (similar to how you did with the CR2032), they are the same voltage but easier to remove and add the battery and last longer. As an aside, although you might not have realised it, taking the battery off board can save the electronics from damage if the battery leaks any contents.
If I may give you an advice, place that battery holder in another spot or at least zip tie it to the wire harness that runs over it. That's because double-sided sticky tapes sometimes tend to loose their stickiness over time, especially in a warm environment like the internals of an electronic instrument. That holder has exposed metal both from the battery and the pins where the wires are soldered, and if that falls on the mainboard beneath it when the synth is turned on, that will make random shorts on the board and you're most likely gonna say goodbye to your DX-7. Not worth the risk, definitely.
Thanks for your advice! I’ll be fixing that ASAP!
@@FelixPrankel You're welcome :-)
A little chorus and Reverb on that e-piano patch and it really comes to life - you have the classic sound of the 80's :)
There are many different "Knopfzellehalter" at for example Reichelt, that should fit close enough directly to the PCB. They do not fall off when the tape gets too warm. Especially as the metal is black and next time the sun shines, your assembly will fall onto the PCB and kill something that is not available anymore as spares. Secondly these coin cells with soldering leads are not that rare and can be bought, but I have to admit, that the two pin cells are rarer in Europe as here we usually use 3 pin coin cells for soldering, the plus has two contacts, the minus only one. But it is easy to bend or cut so it fits to the PCB. Taking into account, that it is to be changed in 10 to 15 years, I'd suggest soldering over taping it somewhere.
The soundwill get better and the hum will go away if you simply replace all electrolytic capacitors. The hum suggests the caps from the power supply are becoming bad and the low audio points to the two polar 1uF/50V caps aside IC53 and the bi-polare 1uF/50V at output of IC54. We can start a discussion about if to change only tested bad caps or all at once. My way is: If one fails, the others will follow as they all lived in the same environment. And check the contacts of the external Volum control port. It is a control signal, but the plug may have some corrosion on the contacts.
@Guitar3000: If you live in southern Germany and don't feel happy to replace the caps and measure everything else to be fine, get in contact with me, you can use my lab and I assist you if needed.
You're a braver man than I am! Well done for getting it working.
Another way to get the DX7 sound is Korg's Opsix. It can load original DX7 sound banks, and it will automatically use the old 12 bit sine waveforms. It's not perfect - there are other RUclipsrs who have covered this in detail - but, editing FM on the Opsix is joyfully easier than on the old DX series.
Lucky to have gotten my DX7 for $100 as well. Lucky Catz ✨🤙✨
Fixing it is a cakewalk. I'll be impressed if you can program it. Most people just give up and blame the synth.
Try the easy-to-fit backlit display. It makes a huge difference!
Well done, interesting video. I have a DX7 myself, lovely thing to play.
I once changed a CR-2023 battery in a DX-7. That DX-7 had a battery holder, so I could easily pop out the old battery and put a new one in.
Subscribed!
Great bargain! Consider replacing electrolytic capacitors inside. Dried capacitors are the most common cause of the low output
And this is one of the pitfalls of those old boards with caps. It's not out of the question he might have to spend over 100 bucks in caps just for the replacement, which will make the keyboard not that much of a bargain.
I was hoping for a sample pack of the initial weird sounds, and am very disappointed. :)
I considered making one, but on second thought, it wouldn't have been much use. They were all very quiet even with the volume cranked all the way up, so they came with a lot of noise. Like I said, not all of the patches even made any sound. Others were the same pitch regardless of the key pressed, and some just sounded unpleasant. So likely, there wouldn't have been any use case for the samples. Maybe I can recreate it in some way.
Nice vid! Fixed those broken sliders next :)
bravo!!!!!!!!
liked and subbed brah
@2:44 - this DX7 has an aftermarket firmware installed. Not the original one :-)
There's no stress in Yamaha- it's a Japanese word.
Elton John's Sacrife didn't use a DX-7 e. piano, but a Roland RD-1000 e'. piano.
So, not sure why I got recommended this, but a lot of people have brought up good points. I know this is a wall of text, but please take a few moments to read. It will save you much time and heartache. Even if you think 90% of my suggestions are trash, the 10% you do decide to do will still help you for the rest of your life and countless projects and repairs in your future.
You do not "reuse" solder, you should remove old solder completely, and add fresh solder to any joints you mess with. You can get away with it somewhat if you add liquid flux on your own, but really.. why? You're already melting solder, already using a solder sucker, why would you add flux to try to reuse what's left.. instead of just soldering with solder? Doesn't make any sense. Especially not depending on the year of the equipment you're working on, where leaded solder, or lead-free solder exists. Adding leaded solder to lead-free joint can lower the melting point and increase the fluidity and lower viscosity (for the same temp), making it easier to desolder stuff and increase wetting and heat transfer, making it safer for the board. By that I mean, the wire or pin you're trying to remove, slides out of the through-plated hole without ripping a pad off either side of the PCB, versus only the side you touch with the iron melting, and you wiggling and wiggling to pull the wire out, and rip the pad off the other side. There are so many ways to mess up. But thankfully a handful of rules pretty much brings the chances down to 0%.
Always add fresh solder to a joint, no matter what, it helps desolder/remove what you're trying to remove, as well as the fresh flux cleaning the area. Try to remove all the old solder completely, you might have to add fresh solder, sucker out, add solder, sucker out, until it's all gone. The same would apply to you trying to make a good joint, but in the opposite direction - getting worse every time you heat it, so don't do it. Add fresh solder, remove, clean all the solder out, then solder with fresh solder on the wire/pin/etc. Mixing leaded to lead-free helps remove components faster and with less thermal input, reducing chances of damage. But you should remove the random crap of indeterminable alloy that remains completely, before soldering with fresh solder.
Add a little section of silicone or teflon tubing to the end of your soldersucker. That heating up with an iron, pulling the iron away, trying to get the tip onto the joint while shaking for 3 seconds and shit cools down, failing to sucker the solder out, and repeat over and over again is not the way to do it. Each time you heat the joint, you're causing damage. This is why you add fresh solder (and flux every time!), and failing that, you will cause the glue that holds both the pads to the PCB on both sides, but also the plated through-hole. Fresh solder/flux, lowers the temp that everything melts at, meaning the amount of time your iron is there is minimized, reducing the damage done to the PCB. Same for being able to use lower temps and still getting stuff done.
Desoldering braid on it's own is useless unless it is pre-dipped in flux, and even then adding your own is best. More flux is always better. The only downside is how much cleaning you have to do afterwards. Flux is what makes soldering possible. You cannot solder without flux. As soon as metals heat up, they grow an oxide skin. Oxides are already reacted and inert, so.. trying to solder with skinned up, dry solder onto heated up and dirty pad or wire, will not happen. It just beads up and doesn't stick. Flux is an active chemical, melting it activates it. It destroys oxides and metal salts. It leaves atomically clean metal surfaces, and keeps air from contacting these surfaces while you're working with them. Because atmospheric oxygen will just.. oxide things up immediately at soldering temps. Flux destroys any crud and oxides, then protects the area and prevents the skin from growing back, and helps the solder wet and atomically bond.
Soldering isn't just.. metal sticking. It's infinitely complex. On a copper wire with leaded solder and rosin flux, the surface of the copper wire actually dissolves into the solder directly, and that gradient of metal alloys causes them to bond at the atomic and molecular level. Same with tin (what coats cheap PCB's and the surface of chips). Leaded solder, after all, is typically 60/40 (or 63/37) tin/lead alloy. The point is, solders are eutectic. That means that these metals mixed together melt at a lower temperature, than either metal on it's own. 60/40 solder melts at 360f while tin melts at 450f and lead at 620f. This is why getting rid of old/mixed solder is important, before resoldering with fresh.
You always clean with isopropyl alcohol. Always. Natural Rosin based flux (used in leaded solder) will undergo chemical changes over time, including becoming conductive causing weird glitches and possible circuit damage, but also slowly corrode anything it touches (i.e. the pads, joints, and pins of everything in the area). Modern "no-clean" / ROHS fluxes are much more aggressive and bad for you, but work quite well for both leaded and lead-free. You should still clean up afterwards. The 15 seconds with some rubbing alcohol and a qtip is far less work, then hours chasing down weird glitches, or your device becoming damaged beyond your ability to repair!
Think about it. Adding fresh solder takes 2 seconds longer for that first heat, but 10x faster than attempting to remelt the area 5-10x with just a dry iron and causing damage. Tip on sucker lets you place it right on the joint, right up against the tip of your iron. You don't move the tip away, then struggle to get the sucker in place. You put them both there at the same time, and when things melt you push the button. Once you get what you want out, sucker out the holes or whatever, going over with some desoldering braid is useful. Gets rid of everything, giving you a perfectly clean and shiny metal surface to solder too.
Wow, some very thorough advice from someone much more experienced than me. Since I'll probably have to replace the caps, this is going to be quite useful. Thank you for taking so much of your precious time!
@@FelixPrankel Of course. I was hoping you didn't take offense, having people come in and WELL AKSHULLY can be annoying, or people just copy/pasting shit without understanding.
I enjoyed your vid and look forward to your project! Also, for what it's worth, you can with caps cheat. You add fresh solder and melt one leg, then you use your finger on the other side to lean the cap in the opposite direction, then you remove iron, wait a few seconds, then melt the second leg, and push it the opposite direction, should take 2-3 times total before the cap falls out. Then you can use the solder sucker to suck the hole clean on the first try!
Also, depending how many layers the PCB has, there are internal layers of copper, and the + and - are usually run on the inside, and have lots of metal to suck the heat away!
Say you wiggle the cap out, and now the PCB is even, solder even on the surface, trying to get it to melt the full thickness can take a while, and if there isn't any flux it won't really melt fully. So adding a big blob of solder lets it mix with the remnants of the hole letting it melt easier. If you couldn't tell, the main thing about soldering is cleaning the tip iron and keeping it tinned, and cleaning the board/area, whether that means extra flux, or using qtip and alcohol, etc.
Good luck, and again, I wasn't trying to be condescending, so I hope it wasn't taken as such
been trying to send the sysex files to mine but nothing happens, all I hear is a light click noise in my head phones whenever the volume is turned up or down, any idea what I should do? (For context I believe mine has an expansion)
In my limited experience, some cheap MIDI interfaces do not transfer sysex well. (I'm sure someone will have more useful advice than that.)
bro doesn't play the guitar3000, bro IS the guitar3000
EDIT: i love dexed, i made an entire album using mostly dexed for the DX7 80s flavor. you can find it on my youtube and even spotify
the dutch saved your DX7. GEKOLONISEERD you might even say
They were sort after about 4yrs ago ,you couldnt find 1 for less that a k
11:57 E
Why you'd fix this god only knows. It sounds like a DX7.