Difference in quality in products made in China?

Well I got my first bad component that was made in China. It was a used XiangSheng 728A tube preamp that was made a couple of years ago. The previous owner babied it and sent it to me in original packaging. I've bought from this seller before and I know his gear is well taken care of. When I got the 728A I was swapping out tubes and removed those metal retaining clips on the tubes and put the tubes I wanted to roll in. I thought I was being careful with the swapping but when all was said and done one of the tubes wouldn't light up. I had no sound from the other channels. I take the preamp to my tech and from what he saw the soldering of the sockets to the circuit board were shoddy. Also I managed to crack the circuit board as well. He said the quality of the sockets used to was so so. This is a budget preamp so I wasn't surprised about the quality of the tube sockets. The soldering as well as the cracking of the circuit board was surprising.

I've been good with the bevy of China made products I've boght. From Tube phonos, Amps and solid state preamps it has been a good experience. This one was a shocker to me.

(http://news.consumerreports.org/safety/2007/06/can-you-trust-c.html) (http://www.guardian.co.uk/technology/blog/2010/jun/29/dell-problems-capacitors) (http://en.wikipedia.org/wiki/Capacitor_plague) (http://rendezvous.blogs.nytimes.com/2012/10/21/maggots-in-the-pasta-europe-screens-tainted-chinese-food/) (http://www.wnd.com/2007/06/41959/) (http://www.dailyfinance.com/2011/03/14/the-10-most-counterfeited-products-sold-in-america/) (http://www.bloomberg.com/news/2011-11-07/counterfeit-parts-from-china-found-on-raytheon-boeing-systems.html) (http://news.sky.com/story/20576/fake-chinese-parts-found-in-us-planes) I find the last two especially disturbing, as I spent a lot of time in aircraft.

My purchase was a 50 watt integrated amp - looked fantastic ,stainless steel chassis, cast aluminum tube cages, remote source switching/volume and it sounded pretty good, but under the covers...

The transformer was not built to 120v spec so the heater voltage tap was measured at 7.1v and not 6.3v as it should have been
- this caused premature failure of a complete set gold lion tubes tubes in 3 months

The circuit board had under rated pcb traces that had to be rewired

Some resistors were under rated for their duty - had them replaced

Capacitors used were sub standard for this type of component - had them replaced

I had it fixed for around $400 and it worked very well

After I had sold it (mainly because I was tired of heating my house every time I played music) I had heard that the output transformers were not a great quality either

Looks can sure be deceiving

I remember a story about stainless steel.

Properly manufactured stainless steel uses iron, nickel, and molybdenum blended to make a shiny and corrosion resistant metal.

A Chinese chemical plant under construction bought cheap stainless steel made in China.

The stainless steel maker had substituted another cheaper metal for the nickel. The resultant product was shiny but not corrosion resistant.

The chemical plant began to experience considerable corrosion after a few months and all of the "stainless steel" componentry had to be replaced with expensive authentic stainless steel. At considerable cost in labor and lost production.

Natural selection at the corporate level?

IMO: China and Korea are capable of making products at any quality level desired. Same things were once said about Japanese products, now I wish I could afford some of them.