Tag Archives: lcd display

Racking a PPG Wave 2.2 – part 2 – display change

Display change

Yesterday I got my new display and digital board back from Alexander at Virtual Music in Vienna. The old display had to be changed to a newer one for two reasons, even though the old one still worked.

First of all, the old one would never fit a 19″ rack since it’s too wide. The new one is 182 mm, so it will fit.

Secondly the old one was very hard to read, especially if you were not straight in front of it. Since the PPG Wave 2.2 is supposed to sit in a rack, sideways visibility is crucial.

As you can see on the pictures it’s not just a matter of swapping the old display for a new one – serious modifications must be made to the so called digital board. The digital board contains the driver for the display and the two keypads. All work was very professionally done by Alexander! I plugged it in and it worked instantly!

The encoder for the contrast was also replaced since the old one was kind of intermittent.

V8.3 firmware

Virtual Music also happens to be the reseller of the newer V8.3 firmware that adds a lot of sysex and fixes bugs. V8.3 was ordered as well as new battery kit. I tried to change the eproms, but the old ones were really stuck and impossible to remove without using brutal force, which I didn’t want to. I will have to install V8.3 when the board is removed from the chassis.

The next step is to order a new 6U 19″ rack chassis.

 

Racking a PPG Wave 2.2 – part 1 – intro

Intro

I recently got this “racked” PPG Wave 2.2. The history of it is quite unknown, but this brutal treatment was done in Germany by someone else than me. I’m innocent!

Someone has cut this Wave in half, removed the keyboard and put the right side  on top of the left side using standard screws and standoffs from a hardware store. It’s a shame since it looks as though the panel was in great condition – most Waves suffer from the graphics peeling of, especially in the area near the logo close to the push buttons.

Software wise it’s running OS V6 and has MIDI. MIDI is the way to control it since it has no keyboard. Since it’s a PPG Wave 2.2, it’s compatible with the Waveterm A – which I don’t have. There’s however an upgraded OS, V8.3, which makes the PPG Wave 2.2 compatible with Waveterm C, a software version of the Waveterm A and B.

Unfortunately, the serial is unknown as on most PPG Waves. It was hand written on a label on the back with a permanent pen that wasn’t as permanent as it was supposed to. It is probably an early/mid PPG Wave 2.2 as it has the same display as the Wave 2 but is equipped with factory midi.

I asked myself – what have I done – buying an expensive piece of junk like this that could electrocute me. And the racking procedure won’t be cheap and will take a lot of man hours. However, I’m running out of space in the studio and PPG Wave 2.2s don’t grow on trees, especially if they’re not upgraded with 2.3 voice cards. So I decided to take on this challenge and make myself a one of a kind rare PPG Wave 2.2 rack. I guess my metal skills from working with cars will be needed…

The width problem

The problem with the current “racking” is that it won’t fit in a standard 19″ rack – it’s simply too wide! A standard 19″ rack case has a panel width of 19″ (483 mm) , but the case width is often closer to about  17.5″. I’ve found a rack case supplier that has a model with an external width of 435 mm and inside width of 432 mm. This means that 432 mm is what I have to deal with.

The mainboard with all voice cards that is on the lower section is luckily enough around 430 mm. There’s also possibility to shave off a couple of mms at the far ends. The pots are placed on a board that is around 400 mm. The “Basis” and “Master Volume” pots to the far left are not on the board and can be placed anywhere.

The upper section has the power supply and MIDI and audio outputs at the back. They can easily fit within in the width. The biggest problem is the so called digital board that has the keypads and the LCD display. Together they have a total width of 460 mm so they can impossibly fit. One solution is to cut boards so one end is in a 90 degree angle (like this racked 2.3). I have  chosen a different path – changing the display to a more modern and narrower one that also has backlight.

The original display must have cost a fortune back then, and it’s not directly compatible with modern displays. Therefore the digital board and display will be sent to Virtual Music in Austria to be modified.

I won’t reuse the original panel metal since a few things will have to be modified and moved around. Instead I will create new original looking graphics for the faceplate so it looks factory.

The plan summarized

  1. Make a plan
  2. Change the display to a narrower modern one with backlight
  3. Upgrade the OS to V8.3
  4. Put everything in a rack case
  5. Create new graphics

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.

Parts

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!

Conclusion

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.