4.4 THE DUOTONE AND SIGNAL PROCESSORS 5.0 REPLACING TUBES, MAINTENANCE AND CARE
The Duotone is equipped with a parallel effects loop, meaning theThe Duotone ships with EL34 and 12AX7 tubes by RUBY¨. Once
original signal always comes through, and the processed signal isthey've been burned in (initial continuous operation under a load),
mixed in with it.these undergo an in-depth selection process where their electrical
values and mechanical status (microphonics) are checked. Beyond
CONNECTING EFFECT DEVICES:that, they're installed in a finished amp and their sound is auditioned
- Connect the FX SEND jack to the input of your effect device andin a listening benchtest. One of the most important steps is power
the FX RETURN jack to the output.tube matching, a process whereby tubes with the same charac-
- Adjust the FX LEVEL control on the rear panel to match the input ofteristics are selected and combined to make matched sets.
your effect device.
NOTE: When you're trying to dial in a suitable signal level, you'll findWHEN IS IT A GOOD IDEA TO REPLACE TUBES?
that it's harder to come up with good results when you're using aThe tubes in the Duotone are exemplary in terms of quality,
multieffects processor that features an on-board preamp (actually,workmanship and long service life. If you nevertheless come across a
any kind of signal boosting circuit) but does not allow you to patchproblem, please be sure to run down the following checklist before
signals in after its preamp and in front of its effects section. The
you swap out your old tubes for new ones:
reason for this is that when you have connected this type ofWas the fault or failure of the power tube caused by the tube itself or
processor to an FX loop, the signal is being routed through twoa flawed peripheral device or component, perhaps a defective
preamps in series. Effects devices that are not equipped with thisspeaker cable? (If you don't get to the bottom of the problem and
type of "preamp" are better suited for use in conjunction with effectsremedy it, it may crop up again even after you replace the tubes.)
loops because response is more dynamic and sound quality
considerably better. If you happen to own one of these everything-
Did the mains voltage fluctuate or spike while the amp was on? In
but-the-kitchen-sink boxes and understandably want to use it, dial inall-tube amps, over-voltage surges in the mains net can certainly
the most dynamic clean sound you can find on the effects device. blow fuses or even the amps. Over-voltages are often caused by
generators or improperly installed high-current power circuits.
- Dial in the desired balance between dry and wet signals via the
FX LEVEL knob located on the front panel of the amp.Did a fuse blow even though none of the tubes is actually
defective? An old fuse, tube de-ionization or mains voltage power
TIP: If you choose not to connect an effects device to the effectssurges could conceivably have caused it to blow. In this case,
loop, you can instead use the RETURN jack for patching in the signalreplacing tubes of course is a waste of money and time.
of another instrument or tape deck (guitar, keyboard, drum
machine, tape player, etc.) for rehearsals or practice sessions. If youTubes definitely show signs of wear when their service life is coming
choose to use the FX RETURN this way, use the FX LEVEL knob toto an end, such as increased microphonics, noise, muddier tone
determine the balance of levels between your guitar's signal and the
through loss of high-end frequencies, degraded performance, etc.
connected signal source. You should take these indications seriously and replace old tubes
because not only do these side effects take their toll on sound
quality, they also indicate the affected tube is about to fail. |
ACEC
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