It's coming together, though not without a few pitfalls. I was looking forwards to taking what is the 861 kit of parts, and simply re-assembling back to something that I knew was going to work. It's not a difficult mod, but getting a new power supply to fit in with that ideal wasn't so easy.

I bolted the PSU chassis into new holes in the processor baseplate. I mounted the filter board alongside, with the ballast resistor clipped to the PSU chassis. I soldered the existing power lead to the transformer, and replaced the DC leads and earth lead.

That was it, really. I checked the continuity and isolation of the DC lines and earth, then fired-up the PSU with no load to check the voltages were as expected. I repeated that with the filter board connected, then finished the re-assembly. That sounds simple, but I did learn a few lessons along the way that I thought I'd share by way of random, rambling guidance for any fools following in my footsteps.

Don�t unscrew the U-shaped perimeter trim at the rear of the case.
Don�t unscrew the transverse extrusion bars to remove the base or the lid.
The front and bottom panels are bent from one sheet of metal.
The top and bottom panels fit into slots in the extruded bars.
There are lots of self-tapping screws that are easy to strip.
The connections to the grounding stud by the power supply card are awkward.
Avoid removing the card rails � they�re fiddly to replace.
Consider whether the parts can be assembled in any order.
Note which way round the display cable & its connectors are installed (they�re not polarised)
The backplane can be removed on its own.
Rigid power supply mountings couple transformer vibration to the chassis.
Use spring + plain washers with every nut, bolt & screw.
Don�t use over-size cable � it's difficult to fit and difficult to solder.
The +5V DC output can use a single line instead of two.
Keep the 0V return lines separate � one for 5V, one for +/-12V.
DC outputs should be kept isolated both from each-other, and from the chassis.
+/- 12V outputs are usually adjustable � check the pre-set value.
The 5V output often has adjustable over-volt or over-current protection.
The power supply must have a good earth connection to the chassis and the mains.
The power supply must be fused per manufacturer�s installation instructions.
The power supply is switched on & off by the switch on the rear, not by the remote.
Get the right tools.
Get a static strap.
Get a good light.
Good luck.

[Linked Image from i270.photobucket.com]

[Linked Image from i270.photobucket.com]

At this point I have to admit that I'm starting to get nervous, as the 800/861 only work at all because they were developed around an SMPS. If they'd been designed around a linear supply, the development would surely have taken a slightly different course. How do I know, for example, that I won't suffer from a mains-related hum on the analogue outputs, that Meridian would never had had to worry about when using an SMPS? How do I know that everything will start-up in the right sequence? How do I know that something won't oscillate? Or a hundred other things that I haven't thought of?

Nick