Yamaha DX-7 Programmable Algorithm Digital Synthesizer

Yamaha DX-7 Digital Synthesizer
Yamaha DX-7 Digital Synthesizer

Back in 1984 I owned one of these in high school. I later sold it when I went to University and never played one again until yesterday. I found a good condition Yamaha DX7 for $25.00 at the local second hand shop here in Nagano-city, JAPAN. The outside condition was fair to good, but the functionally wise it was in excellent condition. In fact, I opened it up inside and it’s near mint. All of the keys, buttons, levers, LCD, controllers, etc were in excellent condition. Jacks and Midi also worked great, so I think I got a pretty good deal for a Yamaha DX7 again. Note that I originally paid around $2000.00 for the one back in 1983-84 if correct. It’s amazing how cheap they are now. Mind blowing!!

Of course the sounds are dated in many respects and there are better alternatives perhaps with the later DXY, SY, FS1 versions, PLG expansions, etc. However, I felt right at home jamming on the Yamaha DX-7 once again and it feels great to find one here where I live in Japan. The gritty 12 bit sound is awesome. Yes, it’s a tad bit noisy, but like my Roland W-30 sampler workstation, it kind of has that great Lo-Fi sound. It just rocks!! I most remember how fantastic the key action was and it is nice to again play on such on such a nice and well constructed key bed. The preset sounds were there of course and they brought back lots of memories, but nowadays with the thousands of sounds available on the internet, I don’t think I’ll be using the presets much if at all.

Actually, one of the reasons why I bought the Yamaha DX-7 again in addition to nostalgia from my High School days, was because back then in the early 80’s there was no internet really. There were no Youtube videos, online PDF literature, Sysex Patch Collections, Forum Discussions, or sites devoted to tips and tricks. In fact I recall just having a 600 patch book which was quite labor intensive to program into the DX-7 only to find that the sounds were not all that hot. I’m very excited about diving into the loads of info and patches on the web which I’m sure will provide a very different ( and perhaps better ) experience with the Yamaha DX-7.

In addition, I registered DX Manager Version 3 a while back with my PLG150-DX plugin board. I connected the software editor to the DX7 late last night and it beautifully communicated with the DX7. I was able to transfer some patches and it seriously improved the sound of the DX7 considerably. It will also make editing much easier of course. Back in the 80’s day, you had to punch in all the parameters using the membrane buttons on the Yamaha DX7. You also had to write all the data out using patch data sheets which was time consuming. There were no fancy editors or storage methods other than the data cartridges. I think I had a few ROM Cartridges but never any RAM. The DX7 I bought yesterday had no cartridges either and with the prices on Ebay, I think I’ll skip those. I think I’ll be able to live just fine with 32 great patches once I find my magical set. Too many patches in the box usually distracts me too much, but that’s just me I know.

I’m also checking out a Yamaha DX7 Ei expansion board from Grey Matter which has long been discontinued. I’ve heard very mixed reviews on this for the DX7 MKI version and actually may leave my DX7 as is. I don’t need to have the DX7 layer, split, or do anything extra really as I can do all that via recording. I just wanted that old DX7 sound to insert into my music when so desired. It would be nice I suppose to have slightly more storage space than the 32 internal patches as I don’t like having a computer on stage, but likely, I’ll never gig with the DX7. It’s a one trick pony at this point although a very nice one!!

Welcome home Yamaha DX-7!!


20 thoughts on “Yamaha DX-7 Programmable Algorithm Digital Synthesizer

  1. I decided to take a stab at installing the Yamaha DX7 E! Grey Matter Expansion card. I found one on Ebay that looked good and the price was very reasonable at $35 with free shipping to Japan. I also wasn’t sure how soon I would see another one, so I picked it up. I am not sure the version number for the E! Grey Matter Card but I do know it’s for the Yamaha DX-7 MK1. Hopefully it will at the very least allow me to store some additional sounds. It will no doubt be cheaper than RAM cards for sure since they seem to be going for $50+ a pop on Ebay. I also figured after installation that if there were any problems, I could simply remove it and insert the default IC chips back into their original place. Everything should be back to normal after initialization again.

    I’ve been playing the DX-7 quite a bit this evening and it really sounds great. I discovered one button membrane is slightly hard to push (#9), but it does work thankfully. I’ll have to check and see if I can make it any easier to make it work when pushed. For effects, I attached a Yamaha FX500 to the DX7 and the effects really bring it to life. I especially like the Yamaha FX500 because the effects, like the DX7, have a sort of unique character. The FX500 and DX7 go together well. I also connected a Boss NS-2 Noise Suppressor to reduce the “hiss” that is apparent on these 12 bit DX-7 gems. Again I am a HUGE fan of the Lo-Fi sound and it’s just wicked on this DX-7.

    I then zapped those tired presets and loaded up some fresh new sounds. The Yamaha DX-7 “F—ing” ROCKS now and I’m having a ball. Just for fun, I also hooked up a Boss RC-2 Looper stomp box so I can now do some nifty layering and looping with the DX-7. I can now layer at will and have as many DX-7’s as I want…well almost.

    The Yamaha DX-7 feels quite different now since my High School days back in the mid-80s.

    I’ll be curious how the DX-7 works with the E! Grey Matter expansion board installation. It shouldn’t be too difficult to solder that thing in there. In addition to the extra patch storage, I am particularly interested in the additional midi control options for tweaking the sounds live. That will be incredibly fun.

    Stay tuned!

    Yamaha DX-7 E! Grey Matter Expansion

    1. Hello everyone!

      First Happy New Year from Japan.

      This evening I tried installing a Grey Matter E! board into my newly acquired used Yamaha DX-7 MKI. The Serial Number is 96982, but I am not sure how to check the OS version number. I believe my DX-7 is ok for installing the Grey Matter E! board but am not %100 sure.

      I recently bought the Grey Matter E! board off Ebay. It arrived just fine but I noticed while doing the installation that two “long” screws needed to clamp down the E! board were not sent to me, but I improvised by finding a couple of screws in my spare parts box.

      The issue here is that I followed the directions by extracting the two IC chips ( Rom IC14 and Rom IC21 ). I then soldered the red wire to IC63 Pin #7 and the black wire to IC63 Pin #10. I then seated the E! board into the appropriate IC14 and IC21 slots. I was able to do all of this just fine and I thought the board was “snug” enough to warrant turning on the DX-7 for a test run.

      Well, after powering up the DX-7, I noticed that I got power but there was no display and the numbers .8 and .68 for example were flickering on and off. It was like there was a short or conflict in the system. I tried re-soldering the wires (carefully!) and re-seating the E! board several times and every time the same thing happened. ( Note I turned off and unplugged everything of course before trying different things … laugh ).

      Thus I was unable to get the Grey Matter E! board to install properly.

      One thing I thought of while writing this post is that the when facing the DX-7 ( as if you are going to play the keys ), the IC chips themselves are upside down. My thinking now is that perhaps I soldered the red and black wires opposite of what they should be. IC63 is actually upside down meaning the lettering on the chip itself is upside down. Thus there is hope that if I try this again later in the week, that perhaps that might be the problem. My wires may have been crossed.

      Otherwise for now, I re-installed the old chips and restored the voices using DX Manager without any issues. The Yamaha DX-7 works fine, but I just can’t seem to understand why the Grey Matter E! board will not work properly.

      I will try to find an image on Google ( if lucky ) showcasing the Grey Matter E! board already installed and see how those red and black wires are soldered. If lucky they will be the opposite of what I did. Otherwise … trash the Grey Matter E! board!! LOL

      This was just a small weekend challenge to see if I could add some stuff to the DX-7. If it doesn’t work, all is not lost as I will enjoy the stock DX-7 no problem.

      If anyone has any other ideas or if you recognize my problem, please let me know.



      1. Just an update:

        I consulted the manual and noticed that the IC63 chip was oriented a certain way with an indentation on the right side. I can verify that I indeed had the red and black wires soldered correctly. Thus it appears I either made an error somewhere with my soldering or seating the board. It’s also possible that the Grey Matter E! board is defective and no longer working properly. I soldered the wires carefully three different times and got the same result. The Grey Matter E! board seemed to also be seated firmly in the sockets as far as I could get them, but I did notice that the screw casing were a bit long. I felt the pins could go deeper if I didn’t have the screw casing attached to the E! board. It would be difficult to pry those off though. Still, it should be been seated properly enough I thought, but I could be wrong.

        I have no idea how to diagnose the problem at this point so unless I find an angle to test things, I’ll probably just file away the Grey Matter E! board and keep the DX-7 stock as it works perfectly and sounds great as is. I don’t think I could sell it as I’m unsure at this point whether it works and wouldn’t want sell a defective board understandably. Oh well!



  2. Just picked up a new illuminated display for my the Yamaha DX-7 off Ebay.

    The replacement appears easy to fit The display comes “ready to plug in”, no soldering needed. A detailed description is sent in English, also with photos for better understanding.

    This the ORIGINAL. It’s the first Ebay seller regarding the illuminated display light kit for the Yamaha DX-7!

    Once I receive and install the new LCD, I’ll update my comment detailing the experience. Stay Tuned!

    Yamaha DX7 Illuminated Display

    1. Today I installed the new Green Illuminated Display into my Yamaha DX-7 MKI. It pretty much was easy to install but there were a few of notable occurrences.

      First the adhesive tape that attaches the plastic cover to the LCD unit is stuck on there very well. You really need to slow down, take your time, and gradually separate the LCD unit from the plastic cover. You most likely WILL snap and break the plastic cover if not careful.

      Second, don’t be alarmed if after you turn on the new LCD that you get black squares with a green backlight. As indicated in the instruction sheet, you will need to adjust the contrast inside the DX7. This is easily done, but will need to be done carefully while the DX7 is powered on. You could do this with it unplugged and powered off, but of course it will be difficult to see your progress.

      Finally, make double sure you do not crank the screws back on tightly or you will bend or break the new LCD. It is ever so slightly thicker and enough to cause problems if you are not careful. I just gently twisted the screws until I felt it lightly but surely secured the display. Everything else was easy and the overall installation took maybe less than 30 minutes to complete. The new illuminated green display really makes a difference and I highly recommend it.

      1. Hello Neo!

        Excellent! When you replace the LCD remember to be very careful when taking off the plastic cover of the old one. It’s a bit tricky and it took me several minutes of careful prying back and forth. Also, the new LCD is slightly thicker so be careful of that as well when screwing it back in. Finally, on my DX7, one of the LCD screws directly over the “Db” key caused it to sustain longer when the top cover was closed and the key played. I had to remove that screw completely to prevent the Db key from getting stuck in the down position when playing. Other than that the new LCD works beautifully and is a much welcomed improvement over the old one. Congrats!! – Jim

  3. I kicked off and email to Route66Studios to check on the availability of the Yamaha DX7 Rom -Version 1.11 Expander they are offering for $28. I have a feeling that they will not have it in stock. Every time I email them they never have anything available. No wonder you have to email first…LOL

    Stay tuned for their reply.

    1. I grew up with the DX7 owning one back when I was in High School in the mid-80s. It brought back some nostalgia having one back again and I so far have enjoyed going through the multitude of voices out there. I find it’s quite easy to load banks on the DX7 compared to my PLG150-DX or SY77, so for testing out and jamming on different voices, it’s been fun. I can then load voices I want later into the PLG150-DX or find a way to convert into the SY77 if necessary.

      I ran the test procedure today on the DX7 ( Function plus 16 and 32 buttons ) and everything checked out just fine. ADJ Ver3 M1.0-1.8

      I’m going to take one more stab at it this week by doing a few things different.

      1. I will try and solder the wires opposite from before. I actually think I got it right the first time, but it’s worth a try I suppose. I don’t think I’ll hurt anything if I just power up and down quickly. ( My wires were actually backwards on the LCD of the EX5 so I know that crossed wires can be a problem. )

      2. I plan to remove the “screw casings” on the E! board. I found when inserting the E! board into the DX7 that it would not effectively “snap” or fit nicely into the mother board. The reason being was that the screw casings were too long. I couldn’t push the board down any far enough I felt. If I remove the casings, then I could possibly insert the E! board much better into the DX7 and eliminate all play and/or weak connection.

      3. I can also try and run the test diagnostics after boot up and see if that kick starts the system should it continue to scramble. Unfortunately, the DX7 has no reset, restart, or reboot function, so the test diagnostics are the closest thing to whacking the DX7 in the head maybe.

      If all that fails, then likely the E! board is a dud or I’m just not soldering something right. I am happy with the DX7 as is though and so I’ll be fine either with our without the E! board. At least it’s easy to pop the old IC chips back in and transfer the old voices.

      Stay tuned! Thanks.


  4. Progress!!

    While checking out some online photos of a properly installed E! Grey Matter board on the Yamaha DX-7 I attempted to match the writing on a couple of the chips on my E! board with that in the photo. To my surprise, I noticed that two of my Chips ( 27128 and 27256 ) were opposite to that of mine. So, I took my IC extraction tool and popped out both chips and reinserted them according to how they were in the photo. ( I have no idea why anyone would need to switch these ). I then re-soldered the wires ( after cutting fresh new wire ) and placed the E! board into the DX-7 as firmly as I could. I then turned on the DX-7 and got a frozen .8 but no blinking. Improvement, but still no dice.

    I then reopened the DX-7 top panel and again pushed down on the E! board and tried my best to push in farther. After my second attempt, I powered up the DX-7 and this time I got a RAM corrupt message. I then powered it off and on again a third time. To my surprise I got the E! Grey Matter welcome message!

    E! for the DX7
    ROM Vers. 2.02C

    It works!!

    I then went through all of the initialization stages but I encountered one problem. I don’t have either a ROM or RAM card for the DX-7. So I had to complete the initialization stage that required the ROM card without the ROM card. Now, I understand the procedures so I figured it should work regardless but I could be wrong.

    Moving along, I was able to get everything configured properly. I powered the DX-7 down and then up again a 4th time and all my values were retained with the exception of the internal memory protect and sysex on/off parameter. I expected this and adjust them accordingly again.

    For the FINAL test I had to transfer a voice from the PC to the DX-7. I was able to successfully transfer a voice and play it back on the DX-7 with the E! Grey Matter Board!


    I can’t save any voices at all. Zippo! The DX-7 will not save voices or any edits made.. I tried to edit a name of an init garbage voice in the DX-7 and that would not save either. It all reverts back to init garbage.

    Thus everything works now but voices will not store. Note that I am very familiar with how to save voices, turn off memory protect, etc. As you can imagine I’ve been reading the E! manual and trying everything under the sun, but voices will not save.

    My only other option at this point is to tinker with the installation. Maybe I need to push the board in further. Maybe my soldering job a couple of days ago was whack and all is well now. Thus I actually didn’t even need to change the chips. Or perhaps the Soldering job is still not right, but changing the chips is what got me the E! board up and running. Lots of scenarios and ifs, so I’ll have to trial and error to see what happens.

    One thing I am not sure about is “where” voices are stored with the E! board. Is it in a chip on the board, or is it the chip that the red/black wires are soldered to?

    In any event, the E! board works, but storing voices is a no go thus far. Almost there!


  5. FIXED!! Hurray!

    OK, I have finally found the problem thanks to Big Manilow’s 2006 post on the Yamaha DX User Group. This is what he wrote below:

    The “Problem RAM corrupt” message is normal after you change the battery.
    Just try to stop and start few times your synth till you will get the “Welcome to E!” message.

    After that you HAVE to follow the initialisation procedure as for a newly installed E! Card.

    If after 4-5 stop-start cycles you still don’t get “Welcome to E!” message then check if you have 3V from battery between pin 14 and pin 28 on memory chips: U2 and U4 (when the DX7 is power-off) .

    If you don’t, there is more likely a bad contact on J2 connector. If after a pull-out push-back the card you still don’t manage to make it work then PM me, I could send you a set of memory chips for U2 and U4 if you manage to unsolder-solder them or send you a replacement DX7 E! board.

    First note that my battery is fine and I didn’t change it on this particular DX-7.

    Wth the post above, I learned that the Memory Locations for the patches are U2 and U4. They are soldered into the E! board so I was pretty sure they had to be correct. The J2 connector was indeed seated into the socket, BUT, due to the fact that the screw casings are a tad too long, I couldn’t quite push the board down deep enough as I wanted to. I didn’t take out the E! board, but I did press both my thumbs on the E! board a little harder and heard a snap! I then pushed lightly a couple of more times. I feel like the board could pop out, but it’s in there and I don’t think I can get it in any further.

    I then powered the DX-7 back up and go the E! Welcome Message again. The battery seemed just fine as my settings were still intact and I got no “RAM is Corrupt” message. I did have to adjust the Internal Memory Protection and Mini In Sysex settings again like with the old DX7 method. I didn’t have to do any E! initialization settings again.

    I finally transferred a voice and pressed “Store” and patch number. Presto!! The Voice saved and I could toggle voices banks back and forth no problem. I have no idea how to save banks yet or even if that’s possible, but voices now work and can be saved one by one.

    Thus it appears my problem is solved and that what I needed to do was seat the E! board a tiny bit farther into the sockets. This actually was and still is very hard to do with how long those screw casings are. If my board pops out, I may have to find a way to cut those off the PCB board and make that E! board stick somehow.

    I also can confirm that the two socketed IC Chips on the E! board were indeed swapped for some unknown reason and this is what was causing my original problem in post #1 above. It was a stroke of luck and attention to detail I suppose that allowed me to catch that irregularity.

    Thus I now seemed to have successfully installed a working E! board for the Yamaha DX7 MKI. Whether it will be solid and stable from here on out, I don’t know, but I’ll update this thread if I encounter any stability issues.

    Thanks everyone!


  6. The installed E! Grey Matter board is pretty cool. I can now load 1 bank of 32 voices at a time with DX Manager. So it’s fast to get all the 320 voices inside the DX-7. Just that alone makes the upgrade worth it. I also like how you can assign the Modulation Wheel to change timbre. Plus voices can be stacked, but not layered. I can also plug in my Roland A-33 controller and the DX-7 will now act as a multi-timberal instrument. Fantastic!!

  7. Just picked up a nice condition Symphony 128 Ram Card from Ebay today. I plan to get an adapter as well so I can switch between the DX7 MKI and DX7IID if necessary. I’m not really into ROM/RAM cards, but considering I didn’t have one at all, I thought this one was a good one to snag.

    Yamaha DX7 Symphony 128 Ram Card

  8. Today I noticed that my Db key ( one above middle C ) on the DX7 mkI is not springing back up all the way when depressed. This results in the sound for that key sustaining longer than usual. As far as I can tell, the spring seems intact, but the key feels like it’s rather mushy. It doesn’t spring back up into action.

    I know I’m probably going to have to open the DX7 and remove or clean the effected key, but I was curious if anyone had similar problems. I’m hoping it’s something simple like a shift in the spring or just grime that got in the way.

    It just happened today so I must have done something while playing it.

    UPDATE — Problem Solved!

    It’s interesting to note that the Yamaha DX7 is a pretty precise piece of equipment. Recently I replaced the old LCD with a new green backlight LCD which ever so slightly is thicker than the old one. This resulted in the screw underneath to stick out a bit more. (Sorry, maybe difficult to visualize). What happened was that the one screw attached to the LCD was applying a little pressure to the Db key which caused it to effectively stay pressed when I played it. I removed the screw since the other two secured the LCD fine and I didn’t want to apply additional pressure to the LCD itself. I closed the lid and this time the Db key played beautifully. Fixed! Thus the problem was caused by one of the LCD screws sitting right on top of the Db key in the Yamaha DX7. Interesting.

    For those looking for additional info on fixing any other DX7 key problem, there is a website that I found very helpful to start with. Perhaps many of you already know about it, but I’ll post here anyways.




  9. I’ve received several emails from readers about their Yamaha DX7 mkI or II not making any sound. Unfortunately, I’m not an electronics expert, but I can definitely point out a few things I would check.

    1. It’s obvious, but make sure your connections are in order.

    2. Make sure the volume and output levels are set appropriately.

    3. If you get no sound out of your headphone and/or output jacks, then you need to open the DX7 and check the soldering for broken connections.

    4. Check the battery and also check to make sure you are getting power to the DX7.

    There may be other things to check that perhaps more experienced users could offer. I also might suggest doing a lot of searching on Google. Sometimes when I have an issue with a synth, I can spend a good day or two searching Yahoo groups, forums, blogs, and even reading the manual.

    If your DX7 doesn’t make sound, I’m sorry I don’t know what the problem is, but don’t lose hope. These DX7s are built like tanks and they are incredibly easy to take apart. It just may mean you’ll need to learn a few things about electronics and how the DX7 operates to hopefully diagnose the problem.

    Finally, if I do find any sort of solution to this common problem, I’ll be sure to post some additional info here. Good luck and stay tuned!


  10. Good to see new life for a great old board. Do you by chance have the original discs that came with your E! board? I have one also in my my DX7 Mark I that I bought new in 1987. I recently changed the CR2032 battery and lost the internal user banks of patches that came loaded on discs with my E! board back in the late 80’s. I would like to get my hands on these additional banks for some of these patches. Not all were keepers but some were! Please let me know if you can help. I have lots of DX7 stuff as well as FM programming theory and technique material in PDF format compiled if you are interested. PS: email site is my company site (self-employed programmer).

  11. hi jim
    i just received a DX7 grey matter card and i’m experiencing what i think is the same problem as you. after removing the original ICs and soldering the red and black wires i find that the the grey matter card is finicky to insert correctly. when i think i have it inserted, powering up the DX7 gives me a bunch of flashing numbers on the LED and grey boxes on the LCD. i’m afraid of breaking something inside by pushing harder, is that really all i have to do?

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