Tube Safety Control (Tsc™) - Hughes & Kettner Grand Meister 36 Mode D'emploi

7 MIDI In: MIDI In is a 7-pin interface, you can connect a standard 5-pin
MIDI cable. The two additional terminals serve to supply phantom power
to the Hughes & Kettner FSM 432 MIDI board.
Heads Up: The FSM-432 comes with a 7-pin MIDI cable. You do not need
a power source for the FSM-432 because phantom power is provided.
If you wish to use a 5-pin MIDI cable, you will however need a wall
wart. For such cases, the FSM-432 provides an innovative mains port that
accepts any AC or DC adapter rated for 9 to 15 volts.
8 MIDI Out/Thru: MIDI Out/Thru forwards signals patched into MIDI
In to other devices. You can connect any external MIDI-enabled signal
processor that you wish to switch synchronously with GrandMeister 36.
7 Tube Safety Control (TSC™)
TSC™ adjusts the bias to improve the amp's tonal and technical
stability and to extend the power tubes' lives. It does this automatically
and continuously, so there is nothing for you to do but to enjoy the
convenience. You can swap tubes easily, quickly, and safely: All the hard
work of biasing gets done automatically, so swapping tubes is an exercise
in speed and convenience. This is a big help not only in case of a defect,
but also when you want to compare different brands of replacement
tubes.
Caution: Replacing tubes is a job best left to qualified professionals!
TSC™ merely spares the technician the biasing effort.
To use the full information TSC™ can provide you with, you will have to
look at the four LEDs in the TSC™ section on the rear panel of the amp.
Each LED is assigned to the power tube occupying that corresponding
position. The LEDs will give you two different kinds of information: Firstly,
they indicate the operating status of the tubes see section 7.1). TSC™
constantly performs an error diagnosis and will even shut down defective
tubes if necessary in order to avoid a total failure of the amp. In addition,
you can easily get a read-out of the individual tube's bias points, using any
standard guitar pick (see section 7.2).
7.1 Automatic Status Indications
All LEDs light up and stay on
All LEDs remain on for as long as the amp is in standby mode. When you
flip the "Standby" switch to "Play", they will extinguish after a few seconds.
If all of the LEDs remain illuminated, the most likely cause is a blown anode
fuse that needs to be replaced by a technician. The anode fuse can trip if
a tube is already defective when the amp is switched on, and TSC™ does
not have enough time to measure the idle current and to then shut the
faulty tube down.
None of the LEDs lights up
The power tubes are operating normally.
8
One LED lights up continuously
If only one LED lights up, then the tube assigned to this LED is not delivering
enough current and has been shut down. If the LED does not extinguish
after a few minutes, this tube must be replaced.
Two LEDs light up continuously
This tells you one of two things: Either the two corresponding tubes are
not delivering enough current and therefore have to be replaced (see the
instructions for one illuminated LED, section 7.1), or the power soak is
active. In the latter case, two tubes are switched off automatically, and the
two illuminated LEDs are indicating this (also see section 6.2).
One LED flashes, another lights up continuously
The tube assigned to this flashing LED is generating too much current and
therefore has been shut down. This tube has to be replaced. In this type
of power amp, it takes a pair of tubes working together to produce the
best sound. So TSC™ also switches the defective tube's counterpart off
(indicated by the continuously lighting up LED), so it doesn't degrade the
other pair's tone. There is no need to replace this tube, because there's
nothing wrong with it.
Now this is where TSC™'s intelligence saves your gig: If a tube failure
like this occurs in a conventional amp, its fuse usually trips and you can't
operate it until you replace the tube and fuse. Thanks to TSC™, you can
continue playing for as long as the LED remains illuminated. Anyway,
please note that shutting down one pair of tubes will halve the amp's
output power from 36 to 18 watts. And don't forget to replace the defective
tube after your show.
7.2 Manual Read-Out
TSC™ is able to check the power amp tubes' bias points to let you
determine if tube pairs are matching. This can easily be done by inserting
a guitar pick into the slot right next to the LEDs while the amp is switched
on (rather than in Standby mode). All LEDs will flash several times. The
number of flashes of every single LED will give you information about the
Hughes & Kettner tube rating of the assigned tube as well as about its bias.
The tube ratings table below (7.3) shows the Hughes & Kettner tube ratings
and how flash counts translate to a rating. For example, if the TSC™ LED
flashes six times, the assigned tube has an S2 rating. The chart also tells you
that the tube's bias point is set to 13 volts.
Please make sure that the difference in flash counts between the single LES
is no greater than four flashes. Only if the difference is no greater than four
flashes, TSC™ will ensure optimum sound. If the difference in flash counts
is greater than four, we recommend installing a matched set of tubes to
improve the tone. This is strictly a matter of tone – technically speaking,
the amp will continue to operate safely.
Heads Up: The two inside tubes and the two outside are matched pairs.
If just a single tube is swapped, ensure the replacement tube's rating
matches that of its counterpart. If all tubes are replaced, ensure they all
share the same ratings. You can buy replacement tubes from your local
dealer. The original Hughes & Kettner rating (S1-S7, 0-12) is shown on a
sticker on the tube.