Tone King Imperial MK II, Руководство пользователя

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Adding Sag / More Compression: If you’d like a little less output power, and a little
looser feel, you might try changing the rectifier tube to a 5Y3. My preference is an old
NOS RCA 5Y3 – these sound better than current production 5Y3s.
Installing Tubes
When installing tubes, you may find it helpful to lay the amp on its face (speaker
pointing toward the ground), on a table, and shine a light directly into the back of the
amp, to aid in locating the position of each tube. Tubes must be installed in the correct
orientation. The smaller, all-glass tubes have a blank space in the ring of pins which
must line up with the blank space in the ring of tube pins in the tube socket, located on
the chassis. The larger, bakelite-base tubes have a small cylinder with an indexing key
in the center of the ring of tube pins, and this indexing key must match up with the
corresponding slot in the socket on the chassis.
Replacing Output Tubes
The output stage of the Imperial is fully cathode biased, and no bias adjustment is
necessary when changing output tubes. The design of the Imperial’s output stage
allows a fair amount of margin for variation in tube characteristics, so any known
brand of 6V6 can be installed, and will work properly and be appropriately self-biased.
Tube Quality
Currently manufactured tubes are built in China, Russia, or the Czech Republic, and
are not built to the same quality standards as tubes manufactures by the U.S.
manufacturers in the “glory days” of tube manufacturing.
We musicians choose to use to vacuum tubes because of their tone, but we need to
accept that the tubes available to us these days can be imperfect devices, and are most
certainly the least reliable component in the entire amplifier.
It would seem that the obvious solution would be to use new-old-stock tubes that were
made back in the “glory days”, when tubes were properly made. However, I’ve lately
been finding that much of the available stocks of such “new old stock” tubes are either
gassy, noisy, or unreliable – I do believe that we’ve reached the bottom of the barrel of
NOS tubes.
Tube problems generally reveal themselves as a crackling noise which can occur
continuously, sporadically, in response to mechanical vibration, or in response to your
playing (e.g. a crackling or other type of noise which occurs only when you hit a note).
We subject all tubes to a thorough burn-in and test procedure to ensure that they are
fully up to spec and operating perfectly. However, you must be aware that the majority
of tube failures occur early in their life and may come about as a result of the jostling
and jarring that an amp can receive in shipping. In spite of the exhaustive testing we
perform at the shop, early-life tube problems cannot always be found in such testing.
The first two months or so are the most tenuous period for any set of tubes. Most
manufacturing defects will be revealed in the first two months of their life, but many are
not detectable in initial testing, even after a burn-in period.
If you notice any noises, cracking, or any other odd behavior of your amplifier in this
period, note that it is most likely to be the result of a defective tube, and should be
debugged as such.