Peavey Invective 120 Manual De Operación página 8

TOP PANEL
29
30
12AX7A/ECC83 x 6
Preamp tubes. Tubes function as follows:
V1 = Crunch/Lead stages 1/2
V2 = Crunch/Lead stages 3/4
V3 = Loop driver/PI driver
V4 = Phase Inverter
V5 = Crunch/Lead stages 5/6
V6 = Clean channel
6L6GC x 4
Power tubes. Apart from 6L6GC, other types can be used including EL34, 6550, KT66, KT88 and 6CA7. When
replacing please use matched quartets of good quality tubes and ensure the biasing is set correctly as described
below. V7 and V9 are switched out of circuit in half power mode.
Please Note: Due to the high temperatures, do not attempt to replace any tubes unless the amplifier has been
turned off for at least 15 minutes. This should only be carried out by a technically competent person.
(29) BIAS ADJUST
Adjusting this will vary the bias supply. This should only be adjusted by a qualified Peavey technician, otherwise
it could damage your tone, or worse, damage your power tubes.
(30) BIAS TEST POINTS
These voltage test points are provided for technicians to use for quickly determining the plate current of each
power tube. Using a DC millivolt (mV) meter, one can measure voltage from the BIAS COMMON to the red
test point for a given tube. The resulting reading in mV is directly proportional to the plate current of that tube
(i.e.: 35mVDC = 35mA plate current). Optimum idle plate current for stock tubes is 26mA per tube.
WARNING: Removing the rear panel will expose the tubes. These are VERY hot and touching them should be
avoided. This procedure should only be carried out by technically competent people and at their own risk.
8
V5
V9 V8
V10
V2 V1
V7
V6
V4 V3