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Akai S1000 Upgrades

Installed the LED based display. It is quite bright if not too bright actually.

So I’ve drilled a hole in the back and installed a 1k LOG pot there.

And installed 22 ohm resistor in series. Together cutting on the LED supply current. Display can now be dimmed. At fully dimmed position it is roughly as bright as stock EL Foil based one. Important, the resistor is crucial, else you might damage the LED unit.

I’ve installed a FF based Gotek drive. Actually the stock M0 jumper setting turned out to be working perfectly fine but I have moved it to S0 position later, to be on the safe side. FF is superior to HxC as it will never make the unit freeze during floppy disk change phase (if you change it too fast).
EDIT: I just noticed the Gotek had an old HxC firmware. While the FF was the latest version.

New power supply in. This is a must! It is known that many Akai S1000’s have been damaged due to faulty PSU’s that are now showing their age (expired resource). This Akai came with a Meanwell RS35-5 power supply which previous owner sent separately cause he didn’t know how to install it. I’ve drilled two holes in the bottom of the unit and screwed the new power supply in. It is crucial to either restore the existing power supply or purchase a new one. Else you are risking to seriously damage the unit!

You can use existing wires just fine. As long as you know what you are doing. Disclaimer: I will never answer any question that involves electricity.

Ok the memory cards can be tricky to install correctly and work if you have mixed sized boards. Here is the setup that I have found via trial and error. Slot 1: 2MB Slot 2: 8MB Slot 3: 8 MB Slot 4: 2 MB

Once you’re done, toss it on top of the S1100 just so you can show others you have both.

Akai S-950 Upgrades Part4: DD & HD floppy to image conversion

So your Akai came with a bunch of DD and HD floppies, you converted them to images, started a Gotek drive only to be greeted with a message saying unformatted disk, or no disk in drive, etc and you have to facepalm yourself. I know the feeling!

The source of the problem is that Gotek HxC does not like having both DD (double density) and HD (high density) disk images on the same USB stick. Even if you set the configuration file to Auto, and use .hfe rather then .img files it just refuses to work. In fact it took me whole day to find the combination that works. But eventually i found a solution to have the content of both DD and HD images on the same USB stick. You will have to do exactly as described in here, else the things just won’t work.

A bunch of DD and HD floppies that we will eventually put onto this small USB stick.

First thing you will need a Windows based computer with a floppy disk drive. You will install HxCFloppyEmulator software onto it. You will then insert your Akai floppy and press Floppy Disk Dump. The program might ask you to install an extra driver in here, so install it if it says so. Once the floppy is being read, use Export, and export it as .hfe file. Make sure you label the files sequentially as DSKA0000.hfe, DSKA0001.hfe etc. I suggest you dump first all of the DD disks, then the HD disks into separate folder.

Here are the same floppies in .img format. I used Omniflop on my old WinXP machine to read the floppies because i thought i would use them as .img files. In the end this method just didn’t work right with mixed DD & HD content, so i advise you to go directly .hfe export via HxC2001 software. Pro tip: Don’t bother with OmniFlop.

Keep in mind what is being described in here applies only if your Akai came with mixed DD and HD floppies. If it only came with HD then you are set already and can write the config file to your FAT32 formatted USB stick, with following settings.

These settings work 100%. Save this config to your USB stick and you’re set.

Now comes the tricky part. You will need to use two USB sticks temporarily. This is in fact the only solution that worked. Eventually it will all end on one single USB stick so this is just the temporary phase. Take the second USB stick, make sure it is FAT32, start HxC2001 and make another configuration and export it onto that USB stick. The configuration will differ slightly, instead of AKAI S950 HD set under the Mode, you will have to choose S950 DD. Think of these two USB sticks as two different floppy drives: one is the DD (double density) the other is HD (high density). Hence one will contain only the DD images, while other only the HD images.

Now count the number of DD floppies. Let’s say you have 12 of them. That means you will need to generate 12 HD empty floppies. Go into HxC, make sure you have set it to S950 HD and generate an empty floppy image. Please read HxC “Floppy Emulator Software – Step by Step Guide” to learn how to generate an empty floppy image. Make sure to select Predefined Disk Layout for Akai S-950. Once the file has been generated you will need to copy it 11 more times. Pro tip: You can in fact copy them a few more times, because it doesn’t hurt to have extra spare few empties for your own sampling purposes, and ONE extra empty that you can archive, so that you don’t have to start HxC2001 software each time you want an empty S950 floppy image. Always make sure to label these new files sequentially. For example: Let’s suppose you have 15 HD floppies that you converted into images and have put them onto an USB stick. The are labeled DSKA0000.hfe – DSKA0014.hfe, that means you will need to label your empty HD images starting with DSKA0015.hfe and continuing sequentially up. More importantly there can be NO gaps between file numbers. The sequence always must be continuous, ie: 0017, 0018, 0019…

The image above shows that we have two USB sticks. On USB stick one we have DD floppy disk images with appropriate HXCSDFE configuration file that we generated earlier for S950 DD floppies. The second stick contains our HD disk images, with appropriate HXCSDFE configuration file for HD images, plus our new empty images that we just generated (shown in blue), plus a few extra empties (shown in purple color) for our own sampling.

What we are doing here is getting 12 HD floppies on which we will save our 12 DD floppies. Because for some reason Gotek does not like having both HD and DD flopy image files on the same USB stick. And this is the source of all the problems, and why we are doing this workaround at the first place.

Now it’s our time to start the “conversion process”. Our goal is to convert our DD images into HD format, so that we can work with HD images only, because that’s how Gotek HxC wants to work, and there aren’t many alternatives around. First you will insert the USB stick that contains DD floppy images. You will start the Akai, and load whole disk using DISK / 02 Clear mem & load disk. Once the DD disk has been loaded insert the second USB stick and save the content of your memory onto the HD disk using DISK / 05 Clear volume and save entire memory. And that it pretty much it!

Remove the second USB, insert the first one and repeat the process. Don’t forget to choose next disk on your Gotek drive using Next button. In our example we would insert USB stick 1 and load a file called 000, we would then insert USB stick 2 and save onto the file called 015 (shown on Gotek’s LED display). Once you finished all DD floppies and they have been saved onto HD images, you can toss away the USB stick with DD images and from now on only use second USB stick which is all HD images.

Doggo approves!

Akai S-950 Upgrades Part3: Floppy drive to HxC Gotek conversion / upgrade

So i eventually made an order, despite the fact the floppy was working just fine, floppy emulator is a way better solution. Just a few days later, the package was here with HxC modified Gotek drive. Special thanks to Acid Mitch.

The floppy is held by these four screws on the bottom of the unit. Remove them.

Now you need to remove the power supply board in order to reach the back side of the floppy drive. And with it being reachable, detach the ribbon and power connector from the existing floppy drive.

Remove this metal frame from the floppy drive. Do NOT rotate anything. Leave the floppy drive aside and take the new Gotek drive and connect it exactly as the old floppy drive was connected.

The result should look exactly like this.

Insert the new drive into the unit, and connect the ribbon and power connector, then screw in the four screws that hold the floppy drive in place.

And here it is. Floppy out, Gotek HxC in.

Akai S-950 Upgrades Part2: LCD display upgrade and modification

Some people are just greedy. In fact it was one of the eBay listings that made me inspire do a thread like this. Just take a look at these prices for these “kits” and below i will show you what is the actual “kit” in here. It’s one single strip connector that cost $0.5 and two wires that are already on your Akai! So someone soldered this strip onto their LCD screen and called it a “S-950 Kit”. Very funny!

So, instead of going for this:

Go for this:

Now in order to use your new display you will need to take out the old one and take a look at the strip connector. That is the type you need. It has to be the same shape, bent, rather than straight. Keep in mind, Akai already has everything else to connect the display. The ribbon cable can simply be detached / attached, no desoldering of the ribbon needed, making this super simple modification. You just need to solder this new strip connector and you are done. Make sure you cut the new strip connector to be 14 pins and not 16, else you won’t be able to attach existing 14 pin plastic connector to it.

Here it is ladies and gentlemen, this connector is what makes S-950 LCD display “kit”.

Make sure to remove the noisy inverter. Your Akai no longer needs it. DO NOT throw away the connector that was attached on the front panel, instead cut the wires exactly as shown above while keeping the connector – you will need that connector later to provide power supply for the LED backlight.

With the new display ready, glue three spacers onto three holes where the original screws went thru. I’ve made spacers from the voltage regulator spacer but i cut the inner part of it (the one that goes into power regulator). Every electronics store has these insulators, since you need them to insulate your voltage regulator before you screw it to the metal case – else the regulator will short. And don’t throw away original screws. Believe it or not, but they will fit perfectly.

As I’ve promised, original screws fit perfectly. However there is one problem…

We have to put the screws from the back side. In order to do that you will need to unscrew the front metal part of the case and slightly put it at the angle in order for the screwdriver to reach the lower hole of the LCD screw.

Now remember that power inverter connector that i told you to keep? The two wires that it is providing are exactly what we need. They are 0 and +5V power supply for the LCD backlight. You might have to extend these two wires to be able to reach pin 15 and pin 16 of the LCD. Make sure you check with the multimeter which wire is 0 and which is +5V and read LCD specs sheet about which pin requires 0 and which +5V.

Or if you want to go full pimp mode, connect just the 0 wire to the LED power supply pin, and send the +5V to the potentiometer on the back of the unit. The specs is 1k LOG (usually labeled as 1kB). You want to connect it as shown in the image above (left and center pin, looking from below) to apply gradual resistance to dim the backlight. Again, these new LCD backlights are a bit on the brighter side, and this mod lets you dim the brightness and thus largely increase the contrast of the display.

Quick test on the bench shows success. Display’s “blue” color is artifact due to camera’s color balance. Display is actually white/black. And once you dim it, looks almost OLED like super sharp and contrast-y!

Akai S-950 Upgrades Part1: Power connector upgrade & cosmetics

Step one: disassemble the unit.

This is the easiest of the mods. For some reason some of the Akai S-950 use a 2 pin power connector which is not compatible with a standard IEC connector and thus our standard power supply cables.


This connector belongs to bin.

You will need a good ole file tool and a soldering iron. Simply remove the old connector. Use a file tool to widen the existing hole and insert the new connector.

You will notice a small board to which the existing connector was soldered to. Add a new wire there and solder it onto the grounding hole pin. In the image above, the new wire is the black one (the one without transparent plastic insulator!), and the location for the soldering point is shown. The length should be the same as the existing two so that you can reach the connector. Then insert the new IEC connector and solder all three wires, with the new wire that you just added going to the middle pin. That’s the ground pin connection. So that from now on your Akai not only accepts common IEC cable, but is now grounded properly.

The good thing is that the holes for the screws will fit prefectly. You just need to file the existing connector hole a bit (from all sides!).

With the unit disassembled, you can do some washing now.

And with generic grey matte spray paint, you can restore the knobs to be as new. Just make sure you sand down the existing paint first. Then 5-6 light coatings from a 30cm / 1ft distance will do fine.

A proper Akai S-950 User Manual
If there is anyone looking for a user manual for an Akai S-950 that is not missing any of its pages it can be found right here: https://donsolaris.com/tmp/Akai_S-950_Manual.pdf The reason I mention this is because of the fact that all of the S-950 manuals that are online are for some reason missing / have plenty of blank pages. This one has all of the pages and no blanks! Horray.

New LED display is too bright? Here’s the fix!

There are a lot of replacement LED displays on the market, however some of them have not been properly configured for some specific synthesizers. For example the stock JHD732-24064C is way too bright when installed in Yamaha SY-77. Not only it will make its life shorter but the backlight is kind of on the light side of the blue, burning too fast IMO. So if you bought and installed a LED replacement LCD for your Yamaha SY-77, TG-77 or SY-99 and noticed it is a little bit too bright, don’t worry. A simple modification is required and you will be all set. I can not confirm or deny that one of the sellers who sells these replacement displays didn’t paid attention to the voltage that supplies the LED element. The fact of the matter is, the LED backlight is set to be driven by 4.7V which is way too much for a LED based element. A classic LED diode is usually set at 3.3V while displays usually go 3.4-3.5V but should not exceed 3.6V. Else the 50,000 hours rating can not be guaranteed. It will be more like 5,000 hours LOL!

It is easy to recognize these JHD732-24064C replacement displays. They come with just a strip cable and no power cable. The power is taken from the logic power supply line. And the value of the provided current limiter on the board is simply too small. If your display is as bight as this, it’s no good:

A friend offered to sell me his TG-77 and as soon as I saw the display brightness in his offer via FB I knew something isn’t right. Since I was looking for a TG-77 anyway, i bought it, but decided to inspect that display – it was way too bright. Unfortunately there is no schematic for this display board, but some visual inspection showed two jumpers on the PCB board that someone enabled. And as soon as I’ve measured 4.7V over the Anode – Cathode I knew we are onto something.

LED backlight full manual control for JHD732-24064C and Newhaven displays
In this article we will create manual control for the LED backlight. That way we will have a control over the brightness of our screen. This will ensure the long life of our LED backlight and also help relief stress from our eyes during late night hours operating on the synth. If you have a Newhaven display, go to the bottom of this article. And please note, this modification applies only to LED based LCD displays and not to the factory installed EL Foil based LCD’s that came on stock Yamaha SY-77, SY-99 and TG-77.

The two wires labeled FROM LCD and TO LED ANODE are actually the two wires that you solder onto location shown in the picture below.

On the back of the LCD unit you will notice two jumpers. Disable the one on the Anode end. That way current can no longer approach the LED and we can install our own current limiter and a potentiometer. Also inspect that the jumper for the Cathode is enabled (connected). While there, solder a wire to the SMD resistor and another wire to the IC’s pin 8. My advice is to buy 1m of ribbon cable and simply take out 2 wires out which will become our “cable”.

You want to apply a hot glue because we are talking SMD components – they don’t like having wires soldered onto them. This is to release the stress from the wire – SMD component junction/solder point which is the weakest point of this circuit now.

You will measure the length of the new “ribbon” wires until they reach the area near the power supply socket. Because that’s where the potentiometer will go.

Now you will drill a hole there.

And install a 1k logarithmic potentiometer with a 47ohm resistor on one of its connected ends.

Setting the potentiometer in zero value and measuring the Cathode to Anode voltage you should get something in this range. If you are getting 3.4V – 3.5V it is ok, but above 3.5V it is not good, so replace 47ohm resistor with a larger value (use calculator to find correct value) for this current limiter. This completes our modification. Power up the unit and set LED brightness at desired value.

Definitely try the minimal setting! The display will turn beautiful dark blue, and in late night hours you eyes will thank you. Plus it will live much longer. As a matter of fact i always have my TG-77 at this setting. It is still bright enough.

Semi manual backlight control?
Of course it is possible. If you don’t want to mess with a potentiometer but just want a fast switch for reduced backlight operation to extend the life of your backlight i.e. when you don’t work on the unit directly but use it remotely and thus not need the display. If that is the case then you can simply add a switch to the back. At the switch Position 1 you will put a 47 ohm resistor and at the switch Position 2 you will put a 1k ohm resistor. These are the values that I have found to give a good response. The rest of the modification is just the same and in the the above schematic just replace the potentiometer with a switch.

Newhaven display modification
Essentially you will do everything as described in here: Korg Wavestation A/D LCD Upgrade
Except that you replace the current limiting resistor (100 ohm) in that article with a wire that goes to the potentiometer with a 47 ohm connected onto. From potentiometer you go to the Red wire of the Newhaven display which goes to the Anode and you are set. The hole and the potentiometer go exactly as shown above.