Modern construction vs old fashioned point
to point wiring?
Most contemporary guitar amps use modern printed circuit boards
for the basis of the electronics. This has many advantages over
old hand soldered techniques. It enables more features such as electronically
controlled channel switching and on board effects. Although it looks
very neat and professional, it can usher in problems. Components
mounted on PCBs have very little scope for movement induced by the
high intensity vibrations and large thermal swings produced in valve
amps.
At right is a section the chassis of a typical modern Fender unit.
It has channel switching by way of relays, and two levels of overdrive
making it very versatile volume and situation wise, and a very effective
reverb. Although brand new, it has already blown the output valves
as a result of poor connections to the base pins, necessitating
re-soldering and replacement of the 6L6GCs. Although It offers more
consistency over it's all valve predecessors, having the power valves
on a rigid PCB is a silly approach.
I currently work in a music college which buys a lot of new valve
amps and I have to say that the reliability of these units has not
impressed me at all. We have had several failures and the repair
cost can be huge for boutique style guitar amps. A major failure
can easily write off a modern valve amp due to the PCB construction.
An electronic fault in an amp using surface mount PCB technology
can render the amp unrepairable to any practical degree.
Recently the power transformer which shorted out in a Mesa Boogie
Express 50 watt cost $700 for the part alone! The old beige tollex
Fender Concert amp featured on this website is 50 Y.O. and fires
up perfectly. It has had 1 x resistor replaced in it's entire life! It
doesn't get used all that often thesedays but I cannot imagine today's
products going that distance. The whole idea of disposable electronics
has no appeal for me. I like simple clunky things that go and go,
and if they stop, can be fixed for two bob.
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