This is an interesting thread. I came across it after a Google search seeking information on Tim Rawson's amplifiers. So how do my comments fit into this thread?
Well it started with a call from an owner who has one of Tim's FirstWatt F3 builds that had gone faulty and he wanted to have it repaired. On opening it up my initial impressions were it was a rat's nest. Very poorly built. I'd seen better efforts by a teenager at their very first effort at building a kit amplifier with no prior soldering skills. Amateur at best, downright dangerous at worst. Those familiar with the F3 is they are normally built into a metal box (usually aluminium) with the sides made up by the finned heatsinks. The most worrying part was the case had no protective earthing. I fully appreciate that electrical safety standards vary from country to country but here in Australia the mains is 240 volts and if this somehow finds its way to the case the outcome could be a severe electric shock or even electrocution. :(
Both amplifier boards were riddled with dry solder joints. Some not soldered at all and I wonder how it ever worked. The wires were fitted to the wrong size crimp connectors and were loose enough to wriggle. Not crimped with the correct tool. The capacitor bank PCB had the star grounding ground away and replaced with a spider web of copper wires that were attached to what remained of the traces by the worst soldering I've seen besides the amplifier boards.
The transformer had been tightened down with so much tension that it had cut right through the neoprene gaskets to the copper windings on both sides. The power switch was fitted to a hole that was too large for it and you could easily push it out of the back panel with minimal pressure. It was also wired to switch the neutral side of the mains rather than the live side as it should have been wired. The IEC power socket had the wrong 2.5A fuse fitted to it which is correct for a 120v supply but not for a 240v supply,
All up it's obvious he doesn't have a clue, especially regarding electrical safety. IMHO it's probably a blessing he's not making any more of these pieces of junk.