I thought ampeg moved to Vietnam, not China?
And yeah, the lead-free solder stuff is pretty wide spread now, RoHS in the UK, Personally never had any problems from using it?
Just about everybody is using the RoHS compatible lead-free solder.
The problems with it are being worked on, but are not yet solved. They include issues of soldering process, flux application etc to get a good consistent joint to begin with. Also issues of relative rates of thermal expansion, A phenomenon known as "tin whiskering" that can cause short circuits, and other miscellaneous issues. Certain solder alloys are better, but some of them are in very short supply, or are proprietory to Japanese suppliers, who have been working with lead-free for much longer than anyone else.
As far as Vietnam, I have heard a rumor that the Loud folks are dissatisfied with Vietnam and are looking to move production again, to china. The "B" series is already made in china.
If true, I would expect some disruption while they get the move done, and a possible learning curve as production gets going. The Vietnamese were "qualified" to make nearly all the stuff at the time of the big layoff. Now there is nobody to do the detail checkouts of sample units that were done before, and which are very necessary.
But I obviously am not connected-in where I would KNOW what was up. If I was, I probably would not be talking about it yet....!
Per construction issues:
The construction referred to as "hard-soldered" in a previous post (control pots soldered on PWB) CAN be a problem, but does not HAVE to be.
There are several ways to do it.
The worst way is to have pots with no panel nuts, and support the board on the pot shafts and the jacks only. That is typical for small stuff, like effects. Major stresses from vibration and handling, and a good chance of problems over time.
Another way is the pots with no panel nuts, BUT supporting the board to the chassis on posts (standoffs). That can be as reliable as any other construction, but is more sensitive to abuse of the pots, since they transmit any "hits" direct to the board.
A third possibility is pots with panel nuts securing them to the chassis, but board supported on pots and jacks only. That is a lot more secure, and with a lightweight PC board can be decently reliable, although it is still sensitive to rough handling. Obviously any abuse of the pot or knob is transmitted to the chassis and not to the solder. There is a chance of a built-in stress if the alignments are not designed right, also.
The fourth possibility with soldered-in pots is pots with panel nuts AND the board supported on 'standoffs". That can be essentially as reliable as wired-in pots. It has only one real sensitivity, and that is to the entire chassis flexing, which can stress solder joints. Alignments can be an issue, but that is a design problem that can be avoided.
Obviously the method with the least stress is to have the pots off-board and wired to it, with all jacks likewise.
However, that method is not without problems. It doubles the total number of solder joints for pots and jacks. The wires are typically unsupported, and can stress solder due to weight and bending in assembly.
The wires can be sensitive to picking up noise. If there are a lot of pots and/or jacks, there are a lot of wires, and noise pickup may be significant.
Finally, the labor is far higher, and that tends to limit the method to the higher end and boutique products.
