It's always been my experience that you can build a very good sounding amp with mediocre parts. Look at Bottlehead or Decware's offerings. They're built with very, very cheap coupling caps and metal film resistors, and indeed sound good. I've also built really decent sounding stuff with "shelf grade" parts. However, if you've not heard a similar circuit built will really good OPTs, a choke input power supply with no aluminum electrolytics, and top shelf caps and resistors, you just can't imagine the difference. I have a saying that I've used for a very long time now. "You can build a *good* sounding amp with poor parts, but you'll never build a *great* sounding amp with poor parts." But, it all depends on how much money one is willing/has to spend. And as I said before, one man's bargain is another man's ripoff!
Colinhester, I can't say I can tell any difference in weight or heft in Chinese guitar amps, and the external fit and finish is definitely not too bad at all. Internally, the workmanship is poor and ratty. Pignoses in particular are indicative of this.
One thing I didn't mention about Chinese guitar amp transformers is that they are typically made of inferior M19 or M32 steel laminations. They are much cheaper than the far superior M6 or M4 grades. Beware of using weight as a gage here. Weight/size can be deceiving, as the iron using the cheaper grades must be made larger to make up for it's higher core losses versus M6 or M4.
Sadly, many U.S. made guitar amp transformers are now made of the same cheaper grades of lamination steels. Also, companies like Peavey and Fender have moved much of their production to China, Korea, and Mexico.
Costcutting measures have done a heavy duty waste number on guitar amps. Marshall for example. They used to make some of the world's best amps. In the early 70's, they went to PC board construction with flying leads to the chassis mounted tube sockets. In the late 70's, they began reducing the number of filter caps. By the late 80's, they went to 100% PCB construction, and incorporated SS clipping diodes to get more distortion instead of another tubed gain stage. Marshall hasn't made a truly great sounding amp in nearly 20 years now, except for the reissues of their vintage amps!
Again as with the audio amps, if you play guitar and all you've ever heard are Crate, Peavey, etc, mass production guitar amps, then you'll never know what you're missing. Good boutique amps such as Aiken or Bruno sound so much more refined and have such better tone that you literally will be ruined from then on. I heard a Bruno about a year and a half ago and still have that unreal tone going through my head!
Once again, some would consider the $5000 Bruno a ripoff, while some would consider it a bargain, which is the same principle as with our audio amps. :)
Thermionic