E-MU Emulator II HxC Floppy Emulator

Ever since I got my EII I’ve been planning to add an HxC Floppy Emulator. These are some of the reasons:

  • One of the floppy drives doesn’t work and replacement drives are expensive
  • an SD card can hold a lot of floppy images
  • I don’t have a computer with a 5.25″ drive, so I have no way of transferring all the EII images I’ve got (could be solved if I get my Mac SE 30 and the serial thing working)

As the EII uses 5.25″ floppy drives, the connectors aren’t the same as for 3.5” drives. To solve this you basically have three alternatives:

  1. Create a new custom cable
  2. Create some kind of extension/adapter cable
  3. Modify the original cable

There’s a comprehensive manual from E M X P describing everything that you need to know about the HxC installation, including diagrams of the cables, whichever one you choose. Since I don’t like messing with the original one I chose to create one from scratch. I skipped the extension/adapter route since it would require a female 5.25″ connector, and I could as well create a whole new cable since I was messing with cables anyway. It’s also worth noticing that the cable is very long, almost a meter, which makes it nearly impossible to find a standard floppy cable and just add an extra 5.25″ male connector. In the picture below, taken from the manual, alternative 1 is the route I took. Alternative 2 shows the extension/adapter cable route.

Drawing of the 1) custom floppy cable that I make 2) The extension cable alternative. Screenshot from the E M X P manual (a must for everyone doing this conversion)
Drawing of the 1) custom floppy cable that I make 2) The extension cable alternative. Screenshot from the E M X P manual (a must for everyone doing this conversion)


  • About 1 m of 40-pin ribbon cable
  • Two standard 3.5″ floppy female connectors
  • One 5.25″ floppy female connector “34-way card edge connector IDC”
  • Lotharek REV F HxC drive (REV F is the 3.5″ floppy version). Buy it directly from Lotharek’s homepage. I should cost around €100, but I’ve seen “unofficial resellers” on eBay selling them for €150-200 – that’s a scam.
  • 5.25″ to 3.5″ adapter bracket, like this (I already had one from a computer chassis)
  • 4 pin Molex to floppy power adapter, like this (I had one lying around, probably included with a PSU)


First thing to do is to up open up the EII, which is a very simple process. Just a couple of standard Philips screws at the back and underneath. Then take the top of. Also locate the 4 screws that attaches the “floppy tower” to the chassis to remove it. 

At the middle of the main board, above middle C, a flat cable is folded, then going to the left, under the floppy tower and up to the drives. Remove this cable and use it as a model for the new cable.

Making the new cable

Prepare the flat cable by removing 6 of the wires to “convert” it from a 40 pin to a 34 pin flat cable. Then fold it at the exact same places and put the connectors at the same place, with one big difference – where the original cable has a 5.25″ for the upper drive, replace this with a 3.5″ connector. I used a vise to evenly squeeze the connectors to the cable. Make sure you orient the connectors the right way. Look for a little plastic piece between the 2nd and 3rd pins on the 5.25″ connector.

Swapping the faulty 5.25″ drive

The lower floppy drive didn’t want to load a disk that I know worked in the upper floppy drive.  Therefore I swapped them and carefully set their jumpers right. Now the lower one worked, but not the upper. Perfect, since my intention is to keep a working 5.25 floppy in the lower position and the floppy emulator in the upper position.

The faulty floppy drive with serial no 143922. Maybe it just needed cleaning, I don’t know –  I’ll keep it as a spare or something. It’s amazing the upper one works after 30 years…

5.25″ adapter and HxC metal work and jumper

I’ve used the HxC in lot’s of different samplers, and it has never properly aligned with the machine I’ve put it in. It always extends a couple of millimeters outside. So I decided to modify the HxC by drilling new holes in its metal chassis. For this I used 2.5 mm cobalt drill and used the adapter as a template. I chose this particular adapter since its pattern on the plastic matched the EII best.

Also set the jumper on the HxC to first position, as in the photos.

Floppy power adapter

For power to the HxC, a Molex to floppy power adapter was needed. Luckily I had a few of these lying around, probably included with some PC power supply, but never used. They can easily be found on eBay for a dollar or two. It’s simply connected to the Molex power connector that was previously connected to the now removed 5.25″ floppy drive.


Simply reassemble the EII the other way around!

E-MU Emulator II key fix

Oddly enough, the E2-key on my EII didn’t trigger as it should, it was triggering very randomly. I suspected this was due to oxidation and opened up the EII.

Removal of a key is simple, but you have to be careful not to break the now 30 year old fragile plastic. You simply push the key downwards at the front, and then pull it backwards towards you.

I removed both the E2 key and its neighboring F2 key to get a better view. Underneath the key there’s a rubber mat which the key pushes on. Underneath the rubber mat is a small metallic surface that pushes another surface on the EII which results in a contact.

Lifting the rubber mat showed serious oxidation on the surface on the EII. I sprayed a cotton swab with electronics cleaner and cleaned the surface from oxidation. After that I put the keys back to test if the problem was solved, which it was!

When the keys were loose, I cleaned them from 30 years of dirt. I was tempted to remove all keys and clean them, but I thought it’s an unnecessary risk due to the keys being fragile.

E-MU Emulator II LCD screen change

One thing that sooner of later will die on your EII, if hasn’t already, is the backlight of the lcd display.  There are basically two things that can go wrong: The backlight itself or its transformer.

The backlight The original EII display don’t use leds for the backlight as modern displays do, but another kind of lamp. These can be replaced, but I’ve understood that it’s quite a lot of work, and it’ll definitively die on you again.

The transformer transforms 5V to a much higher that supplies the backlight with power. These kind of transformers often emit a high pitched frequency which can be quite annoying.  Since my transformer didn’t sound at all, I thoguht that this might be the faulty component, and not the backlight itself. The transformer used on the EII is the NEC NEL-D32-46.

The solution is to replace the whole lcd display with a newer one that has led-backlight and remove the transformer. On my EII I suspect someone has been doing some kind of operation on the display before, since the display wasn’t physically connected to the display.


EII OEM displays can be bought on eBay for a lot of money, and they will die sooner or later. There are also other modern “EII/SP1200 replacement lcd displays” available, but they are way overpriced.

Probably any standard modern 16×2 lcd display will work, but be careful when you look for one that it has the correct dimensions, 84×44 mm. Most 16×2 displays that you find are 80×36 mm, and they a) won’t fit in the standard mounts b) require a new flat cable to be soldered to the upper board. Take my advice and get one in the correct dimensions! There are some lcd displays avaible that don’t have backlight, you don’t want one of those. The lcds with backlight are usually 13.5 mm deep, the ones without 9mm.

I found a suitable lcd display manifactured by “Midas” on the UK eBay for around $30 including shipping to Sweden. They can be found much cheaper on Farnell and RS Components, but they require that you purchase stuff for a minimum amount.  I chose the model with blue background and white characters.  You’ll also need a new hex-inverter chip and two short wires for the power.

  • Midas MC21605A6WD-BNMLW 16×2 lcd display 84×44 mm with backlight, I bought it from here
  • Hex inverter Texas Instruments SN74LS04N (this was strangely enough in a zipper bag included with my EII when I bought it…)
  • A pair of 5 inch red and black wires

Replacing the display

Start by opening the EII and remove the upper board that the display is mounted on. More details on that in the E-MU Emulator II slider pot A replacement post.

First thing was to remove the transformer. I cut the melt glue and then used a solder sucker and some heat to remove it. I then soldered the red and black wire to get 5V and ground from the same place as the transformer did.

Next thing, and probably the most time consuming one, was to desolder the 14 pin flat cable from the old display. First I removed the four nuts so that the display was loose from the board. I then had to use plenty of heat and soldering wick. Because of the heat, the insulation on the flat cable took a hit and split itself, but that was actually not a problem, I see no risk in short circuits.

Next step was to solder the 5V and ground wires to the new display, 5V goes to hole 15 and ground to hole 16. The flat cable’s 14 pins goes to hole 1-14. I then reattached it with the nuts and nylon spacers to the board, it was 100% perfect fit!

Just for fun,  I booted the EII to see if my desoldering action had caused any damaged, but it didn’t! I did see the garbled text in the new lcd that I’ve read about in forums when you don’t have the correct hex inverter.

I turned the EII off and located IC25 on the right lower board, it’s near where the floppy cable connects. Make sure you work the right board and not the left, because there’s an IC25 on the left as well with the same physical dimensions! I removed the original RCA H 506 and replaced it with the SN74LS04N and booted. It worked, and it looked great!


I really recommend doing this switch, the display is very easy to read and also has a good display angle. The hardest part is desoldering the flat cable, other than that the swap is straight forward. Make sure you get a display in the correct dimensions as well, 84×44 mm, and double check that it features backlight.

E-MU Emulator II slider pot A replacement

Sooner or later one of the slider pots will fail on the Emulator. This has happened to the ‘A’ slider on my copy. The fault was that it simply didn’t work, no values were changed when sliding it. When I bought the EII, this slider was also missing a cap, so it wouldn’t surprise me if someone had done something to it before.


Replacement sliders can be bought on eBay for $15 + shipping or much cheaper somewhere else. I bought the exact same slider pot and capacitor at my local store, Electrokit, and it set me back $4 in total.

These are the parts that I got:

  • Slider pot 60mm 10k lin 40920001

  • Ceramic 100nF %0v Y5V axial capacitor 41003074

A few months ago I also bought a new slider cap on eBay for $5 + $2 shipping, it could probably be found somewhere else much cheaper.

It’s important to make sure that the slider has the correct form factor, in this case the “arm” that the knob will sit at was 5mm too short. On the other hand, the original sliders are mounted with 5mm nylon washers between the board and the slider. By skipping the washers, the new slider arm got the exact same height as the original ones. I stupidly forgot to photograph it…

Worth mentioning is that the four pins on the slider were positioned differently than on the original. They did have similar markings though: 1, 2, 2, 3.

Replacing the slider

The replacement process itself is very straight forward. Start by opening the EII and find the upper left board. Disconnect all cables that goes to it, and on the front remove the four slider caps and the volume knob. Finally unscrew six Philips screws and the board is loose.

The slider is then screwed to the board with two smaller Philips screws. I started by desoldering the wires though, before unscrewing the slider. I opened the old slider and it was obviously physically damaged, no wonder it didn’t work.

Then I screwed the new slider to the board without the vinyl washers in between, and soldered the wires and capacitor to the corresponding pin numbers. Luckily the wires were long enough to reach the pins even though the pins were physically in different positions.


I’d say the operation is very easy to do and that the A slider really is something you can’t live without unless you can settle for presets. The A slider is used for fun stuff like cutoff, start- and loop points etc.

RME Octamic D

I just purchased and installed the perfect companion to my Fireface 800 – an Octamic D! This means that the Alesis AI3 and Behringer ADA8000 are out the window.

Even though I now only get 8 ADAT channels in instead of 16, the Octamic D supports S/MUX (sample multiplexing) which means that the 8 channels can be run at 96 kHz using two ADAT connections. Also, the converters are probably much better. I’ve noticed before that most stuff sounds more defined using the Fireface outputs compared to the ADA8000 or AI3. The ADA8000 sounds better than the AI3, according to my ears.

Installation was very simple, I connected the Octamic’s MAIN and AUX ADAT outputs to the Fireface’s ADAT1 and ADAT2 respectively. On the back of the Octamic are six dip switches that I set to internal sync (Master), 48 kHz and “Double mode” (=sample rate *2). The Fireface automatically detects itself as slave (synced by ADAT)  and is set to 96 kHz  when the Octamic is turned  on.

Screenshot of the Fireface Settings
Screenshot of the Fireface Settings

The manual of the Octamic D if anyone is interested!

Roland Juno-60 & TR-626

Today I did a great package deal, bought a Roland Juno-60 & TR-626.

My Roland Juno-6 is one of my absolute favorite synths, and nothing I’d ever sell – but it has one “problem” – no patch memory. To be honest that isn’t exactly a show stopper –  it’s a simple synth, and writing down the settings on paper isn’t that hard. However, when a Juno-60 in about the same condition appears locally for the same price I paid for the Juno-6, “upgrading” to the Juno-60 was a no-brainer.

By incident, the guy was parting with all his stuff and also offered me a TR-626 as a part of the deal. To be honest, I don’t know what to do with it since I’ve got the heavy digital machines like the LinnDrum and Oberheim DMX, but it has actually grown on me. It actually sounds quite gritty and louder than the beige box suggests…

Syncing LinnDrum, Polysix, JX-3P and Juno-6 with Logic (or other sequencer) using ReCycle files for external clock

Download RexSync files

The longest title of a post so far, but it describes exactly what this post is about. Syncing those vintage instruments with a modern sequencer without any additional hardware. The only thing needed is a sound card with more than two outputs.

How the vintage stuff works

In this tutorial I’ll be using three different instruments. They all have different kind of functions that deal with time. The LinnDrum is a drum machine and therefore has a built in sequencer which you can set at a certain BPM. The Roland Juno-6 has an arpeggiator with a simple slider – you never know the exact BPM it plays back on. The Roland JX-3P has a very basic 16 step sequencer which also has a simple slider and therefore unknown BPM.

For the instruments to know when to hit the next note or drum sound they have a built in clock. The clock generates pulses, and a pulse is simply 5V for a couple of milliseconds.

All the instruments each have one input jack at the back allowing us to feed them with our own pulses instead of the ones from the built in clock.

The Rolands are the most simple ones. Each time you feed the Juno-6 with a pulse in the “arpeggio clock in” input, it plays the next note in the arpeggiator.  The JX-3P works in a similar way, feed the “seq trigger in”  with a pulse and it plays the next note in the programmed sequence. This means that if you want your sequence or arpeggio to run play 16th notes, you just feed it 16 pulses each measure.

The LinnDrum works in a similar way, but it expects 192 pulses each measure to its “sync in” input jack. This might sound like a lot – and it is. If you listen to the sync signal sent to the LinnDrum it’ll sound like a very loud, annoying buzzing sound, whereas you in a 16th pulse signal would hear each pulse as a “tick”.

In addition to the sync in jack, the LinnDrum also a sync out jack. Back in the day, when recording a song with a synced LinnDrum, you’d do like this:

  1. Connect the sync out from the LinnDrum to your mixing desk, preferably to the last track, eg 24. The reason for putting it at 24 is that the signal is very strong, and could “leak” to the neighboring track (23). Track 23 might have to be unused of this reason.
  2. Run the LinnDrum for a little longer than the song duration and record the sync signal to that track.
  3. Connect the output of channel 24 to the sync in on the LinnDrum which would make LinnDrum sync to the recorded track.

To sum it up: External syncing of these old instruments work in a very simple way – you override the pulses from the built in clock with  your own external pulses.

How my convenient solution to this works

So, from where do you get the pulses? There are hardware solutions like the Doepfer MSY-2 available, and software solutions like AU/VST sync generator plugin.

My solution is very simple and convenient. I’ve sampled a clock pulse from my LinnDrum and created a couple of Recycle files that each are one measure long. These Recycle files has pulses from 1/4 note up to 1/192 note. As you probably know, Recycle files are like Apple Loops, they automatically adjust to the tempo of the sequencer by using a “slicing” method.

How to use (in Logic)

  1. Create a new mono audio track.
  2. Set no input and choose the output to eg output 3 of your sound card.
  3. In your sound cards mixer application, make sure that output 3 isn’t patched to your stereo output. You don’t want to listen to the sync signal, it’s quite annoying.
  4. From the output 3 jack of your sound card, connect a cable to the sync in on your instrument.
  5. Drag and drop one of the Recycle files to the track. You’ll get an error message, here it’s important that you choose Don’t fix, otherwise Logic’s “fix” will make it go out of sync.
  6. Press play in Logic and hopefully the instrument will start to sync!

Roland Juno-6 instructions

  1. Insert the cable with the sync signal in “Arpeggio clock in”
  2. Turn on the arpeggiator
  3. Try to play on the Juno-6 (nothing should happen)
  4. Run your sequencer
  5. Try playing again, arpeggiator should now sync to the sync signal

Korg Polysix  instructions

  1. Insert the cable with the sync signal in “Arpeggio trig in”
  2. Turn on the arpeggiator
  3. Try to play on the Polysix (nothing should happen)
  4. Run your sequencer
  5. Try playing again, arpeggiator should now sync to the sync signal


Q: Nothing happens!
A: Make sure that the sound card’s output really outputs the sync signal.

Q: I can’t stand the noise!
A: You have to configure your sound card not to include the audio output that’s used for the sync signal in the master stereo mix. On my sound card, the RME Fireface 800, this is done in the Fireface Matrix.

Q: Sync is not synced!
A: The output level of the sync signal is important. A level that’s too low can make the instrument miss certain pulses.


M-Audio Axiom Pro 25 / 49 / 61 hex files for flashing with JTAG

Download axiom-pro-25-49-61-firmware-hex.zip

Text from the readme:

These are hex files of the firmware for the M-Audio Axiom Pro 25, 49 and 61.

Most 1st gen Axiom Pros sooner or later get “bricked” because of some bug in the firmware – yes, it’s a self-destructing firmware. M-Audio won’t
help you since they changed owners and therefore claims they have no responsibility – a scandal…

Roger Roumen has discovered how to flash the firmware using the JTAG interface directly on the board, instead of using the USB port (which doesn’t
work since the Axiom Pro is bricked).
See the video here: http://youtu.be/mIqwYbaZw28

The problem I ran into was that the hex files generated with bin2hex using the command “BIN2HEX.EXE /O0x4000 /4 opalXX.dfu opalXX.hex” resulted in
276 015 bytes large hex files, instead of the 315 439 bytes large hex file provided by Roger. When flashing these files the Axiom Pro would still
be bricked.

I eventually tested to flash my Axiom Pro 49 with the opal61.hex provided by Roger and the thing actually booted and worked, though it said Axiom
61 in the user interface! I tested some of the features and it seemed to work ok, I guess the mainboard is the same on all models. However, I
wasn’t satisfied with this solution.

After taking a closer look at the hex files, I discovered that the opal61.hex from Roger had 512 more rows (row 2-513) than the ones converted with
bin2hex. I then copy and pasted those rows from the opal61.hex to the opal49.hex and flashed my Axiom 49 Pro. It worked flawlessly! Therefore, I
suspect that this will work on the Axiom Pro 25 as well.
opal25.hex, created by me, untested
opal49.hex, created by me, tested and verified
opal61.hex, created by Roger Roumen

FIY, I used a $15 Keil ULINK 2 clone from eBay to flash.

Check out my blog;


Korg Polysix arrived

Today my “new”  Polysix arrived. Cosmetic condition is quite good, with the exception of one major dent in the fake wood. It has the CHD midi kit, though I haven’t had time to test it yet.

It’ll need a cleaning and the factory presets, because the current presets are not very exciting at all. The filter sounds amazing, and I really like the built in effects!

E-MU Emulator II bought on eBay

I just did something quite crazy – I bought an EII on eBay. It’s said to be working with the exception of the disk drives.  Those could and should be replaced with an HxC anyway. The big challenge will be shipping it to Sweden. To be continued….

Continued: It will be reshipped in a container since it’s larger than USPS allows. Will probably arrive around Christmas. Worth waiting for…

Bonus: someone has re-created “West End Girls” on an EII.  Fantastic!

80's synth and sampler blog