Rawson Amps

Chewrock, is the heat sink you used also DIY or is it commercially available retail? I may buy a First Watt something, but the Class A heat and wasted energy especially WHEN IDLE bother me quite a bit. Given your expertise, I'd appreciate any thoughts how to alleviate those concerns, such as circuit mods to reduce power consumption on Standby but keeping the amp warmed up and charged up. Would it to difficult to accomplish?

Thanks, -- William

There are people out there that download music illegally and think nothing of it. Just as in this case there are people that will reverse engineer products of simply take someone else's diy designs and market them for themselves against the express written wishes of the designer. for me, this is a no brainer. Just say no. But as you can see, some people find all manner of justifications to do things. even when people tell them that is is not right. I listen to college student argue about how expensive music is to purchase, so they justify downloading music for free. Wrong is wrong. Taking someone else's design and marketing it is simply wrong. Buying such a product, knowing it was marketed that was is wrong also. Places such as China may feel it is okay to steal from western countries, and sell them as something else, until it happens to their designs and then they because all "legal". People like Nelson Pass have gifted us with many of his designs and correspondence to help the field appreciate what it takes to design and build equipment. His policy is, as long as you don't market or sell it, have fun. It doesn't get better than that. His website explains the engineering and formula behind his designs better than most books I read in College. I'll build it myself before buying someone else's ripped off design product. I'm not holier than thou, but in this case, nope, I'll pass, thank you. I appreciate Nelson Pass' work.

enjoy

What Tim Rawson has done is theft plain and simple. Nelson Pass has let the DIY community in on his designs with the understanding that they are not to be sold commercially and used for the builders personal use. He did this because he has an affinity for the DIY community. Nelson got into this business because he was a DIYer in the beginning. Because of people like Tim Rawson Nelson Pass no longer pusblishes the service manuals of obsolete equipment on his website. Even though they are obsolete those designs are still copyrighted. Minori hit the nail on the head. People will justy their illegal deads as long as it benefits them. There is simply no excuse for being a low life thief. If the shoe fits wear it.

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.