emusonacid! legacy

Anybody able to tell me if upgrading an ultra to 128 voice is possible using the chips from a 128 voice non ultra?
The non ultra chips are labeled IC402 I believe this gives the extra 64 voices and 2x IC413 and these are 32 part filter chips.
Aren't these the same as the ultra requires?
Couldn't I just swap them out? It's seems to good to be true, is it that simple?
Are there any other chips required/instructions available on the voice upgrade?

No way I thought the same thing not too long ago so I messaged a guy i know who used to tinker with these things all the time and here was his response.

"Yes I think you can do this. emu used the same chips in loads of there products particularly G & H chips. The main differences between 'classic' & 'ultra' were processor chips and cpu ram if i remember rightly.

I have never seen the voice upgrade kit but by looking at the TSM (pdf page 276[ultra] & 177 [classic]) + looking at your pictures, I can only assume that the kit consists of 2x IC413 filter chips (just like the ones already installed) and a different size 64 voice chip that slots into the socket labeled G20 exp (U59 Master #1 [sheet 13]).
For the filter chips it would be a case of de-soldering and removing all solder from the pins and simply slotting them into the sockets but for the voice chip you would have to surface mount directly onto the main board. Or you could remove the IC413 sockets and surface mount everything. One thing to check would be weather the surrounding components (around the IC402) are the same on the 64 voice board but it does look the case on your pictures"


I checked and all the same components surrounding the voice/filter chips are present on the E-synth (64 voice) meaning it should just be a simple swap.
I didnt want to do the swap on my e-synth ultra in case I messed something up so bought a 6400 of the bay 3 & 1/2 weeks ago but there's still no sign of it and no response from the seller.

heres the pics of my e4xt and my esynth

Thanks catch22. Good images and helpful info.
From the looks of it a 64 voice chip can be fitted into a chip adapter and slotted into A without soldering.
The second option is to solder it to B

It would appear that the 2 filter chips just slot into the surface mounts at C but maybe they also require an adapter.

I'm thinking of trying this upgrade but I need more info guys.
Could someone post the instructions as a PDF for the 128 voice upgrade ?
Does anyone know if the adapter/s are available as an off the shelf component?