(jayjayuk) I see you found your project. I suggest to not suffer with OpAmps unnecessarily, just do the Third Mod and you will save time and money. There is even a more simple way i have not mentioned in the thread, because i wanted to get the best result out of the system, not just do some upgrade. Basically the the C100, C200, C300, C400, C500 SMD components are 0.47uF ceramic capacitors, if you leave them untouched and just use a wire where i used the big 0.47uF axial capacitors you get the very same result, except the sound quality. Later you can upgrade further if you wish.
I know many people love the control pod. But, if you use a cable and connect the system directly to a good analog sound source and use 5pcs 22K resistors on the signal path for the surround instead ordinary carbon film pots, you make far the best Z5500. Require only 2 OpAmps!
Bass redirect need to be turned on in the Creative software. If the bass is to much for the original sats, about 10uF NP caps in series should be enough to cut it back. Or other 2 way speakers capable to handle it will turn out perfect.
I have made a "Pod" from a project box and i have installed a LED, On/Off switch, Jack socket into. The switch serve as instant mute too, if something go wrong to set the proper volume in Windows. While the system sleeping the Jack socket is working for a headphone, when the system is on, the jack disconnected to be sure not interfere with the sound.
You are right, I have what you need. You can cover the sipping cost to your location, i need nothing else. (details in private)
From 12 faulty boards i got 4 with problems related to those regs. Normally they are not running too hot, so maybe they have suffer damage or the short circuit ruined the capacitors belong to them and they struggle to maintain the proper voltage. All the 12 OpAmps hooked up on them so you can figure out what could happen if they fail and let the juice just go. Existing short circuit is also an option to consider.
(andro6600) In the first time I have used cheap Pilkor MKT film capacitors in the Zobel network and the owner liked it. Usually the Wima MKS doing well for audio, look like this position is an exception. For my friends i have used Polystyrene capacitors (Excellent sound characteristic, out of production, difficult to source) and on the boards i had for sale K73-11 160V and MMWA 250V axial capacitors. To be clear i do not own the system, so my hearing not exactly up to the level after few weeks listening against who have the system for years, so i trust your judgment. The only thing is the sound is usually getting better after the a proper burn in period, so maaaybe there is a chance for improvement.
If you asking what i suggest to try, i recommend the 0.22uF K73-16 63V Soviet military film capacitors. They are almost as good as a piece of copper wire by listening and not generating noises according those who have done experiments with them and have the proper measuring equipment. You will find the Polyethylene terephthalate is not highly recommended for audio purpose, but i have to say the shape, construction and size of the caps just matter as much.
I have found 3 different ceramic capacitors on the preamp boards this far. On the pre Pid 636 SMD ceramic, after that ceramic disk, on the latest series MP0/C0G. I have not dig deep into the word of the ceramics just experienced and told to avoid them for audio, so i have no more info on them I'm afraid.
Edited by ramachandra - 6/7/14 at 6:29pm