8 - Upgrading from 64 to 128 voices

Author: sgeorge, Posted on: 21 August 2020 14:52

The advantage the E6400 Ultra has over the E5000 Ultra is that it can be upgraded from 64 to 128 voices. It has all the requisite components installed to support it except for 3 main chips.

The downside is, you'll never find any upgrade kits on the market for them.

If you could find one, it would be really simple, you just plug three chips into the motherboard!

Since we dont have a kit, we need to make one.

Enter the donor Proteus 2000.

This sweet little P2K was purchased without a ROM in it, making it more or less useless, but in full working order. Not bad for 73$!

Lets take a look inside

We can see an early revision mainboard (There were two, a 1998 and a 2000) layout. It also came with OS1.03, which was the first release, so this is an old one!

(For no reason at all I did upgrade the P2K to the latest OS2.26 and ran diagnostics which gave a 100% pass to the G+H chips.)

Looking closer, this is what we are after!

We only need 1 of the "G" chips, IC402, and two of the "H" chips, IC413.

The Proteus 2000 has 2 "G" chips, each one responsible for 64 voices, and 4 "H" chips responsible for 32 filters each.

Our E6400 Ultra already has 1x "G" and 2x "H", so these three chips will bring us up to 128 voices and turn it into an E4XT!

Interestingly the IC413's in the P2K were manufactured on 9915, the IC413 in my E6400 Ultra were 9916, one week after.

The IC402 in the P2K is 9912, vs my E6400 being 9915... 3 weeks.

An oddity I just find interesting. I imagine E-MU didnt get chips fabbed very often in great qunatities.

So, we must say goodbye to this P2K, as its going to give its life so our E6400 can be upgraded.

Removing surface mount chips is not something I'm good at, so I'm going to dremmel around the chips pcb, stick them on a nice flat frypan on the stove to supply heat enough to melt the solder and pick the chips off..

Once done, the two IC413s will just drop into the PLCC sockets, but the IC402 will need to be soldered on.

Now, the upgrade kit has the IC402 on a PGA board, but I dont know the PGA pinout to make one, so we are just going to solder it directly where it would be.

What? dead bugs? No, I just hot air removed them and they are on their backs. They do need a little cleanup. I need to make sure none of the pins on the IC402 are bent.

All soldered, plccs pressed into place.

Aaaaaand... hit the power... here we go, 128 channels!

So, one last thing to talk about with this upgrade, on the board is a jumper called "ID". I never had verification if its required for 128 channels or not.

The schematics are not clear.. but I tested it and here are the results.

With _NO_ jumper installed (open pins), when you boot up it says

  • "Software: EOS v4.70"
  • "128 channel card installed"
  • "Effects installed"
  • "MIDI Option card installed"
  • "128mb of Sound Memory installed"

With the jumper installed (pins closed), it does not print that line 128 channel card line;

  • "Software: EOS v4.70"
  • "Effects installed"
  • "MIDI Option card installed"
  • "128mb of Sound Memory installed"

Either way, it shows 128 channels in the About screen.

If you put the jumper there, and you only have a E5000/E6400 with 64 channels, and boot up it will show 64 channels so it tests them either way.

tags: Audio, E-MU, E6400 Ultra, EOS4, IC402, IC413, Proteus 2000, Sampler


Comments

rvense said on September 09, 2020 15:01:30;
      I've been wanting to try this for a long time, but I've never dared. Good work!

Also happy to have the ID jumper mystery cleared up. I think I tried stuffing it on my 64-voice Ultra, and it froze during boot around where the number of voices is normally printed.
 

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