ALLNIC AUDIO L-85000 OTL/OCL, Руководство пользователя

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CURRENT METERS
As noted previously, there is one current meter for each channel on the top of the L-8500 (See
Figure 5). These meters indicate the status of the current supply to the gain tubes in the L-8500
OTL/OCL. If the gain stages are set up and functioning properly, the needles of the meters
should be in the centre between the two parallel lines in the middle of the meters.
These illuminated meters perform two functions:
•
First, the meters are used to balance the outputs of the third gain stage tubes for the right
and left channels (See previously under Initial Set-up).
•
Second, the meters are indicators of failure or damage to the function of the unit. Any
failure of the tubes or circuits in one or the other of the L-8500 OTL/OCL’s channels is
indicated by the needle on the meter for the respective channel moving out from between
those two parallel lines.
•
If the needle has moved to the left of the parallel lines on either meter, it means that
one, or both, of the third gain stage tubes (12B4) for that channel is failing.
• If the needle on either meter moves to the right of the parallel lines, it means that
either one or both of the first and second gain stage tubes (6AN8 or 12AU7) for that
channel is failing.
• Remember, once any of the 12B4 tubes have been replaced, before powering the L-
8500 back on, be sure to turn the screw for each meter counter-clockwise about half
a turn. This will ensure that the needle is on or below the left-hand parallel line on
the meter’s face when the L-8500 is powered back on. After powering on, readjust
the tube bias for each channel so the needles of both meters are in the centre
between the parallel lines in the middle of the meter (see gain stage balancing in the
Initial Power-on section above). The L-8500 must be powered off to remove and
insert tubes.
In case of any failure indicated by the meter, please contact Allnic Audio or its authorized
representative for assistance.
TUBES
The L-8500 OTL/OCL uses the following tubes (see Figure 5):
•
Two (2) x 6AN8
•
Two (2) x 12AU7
•
Four (4) x 12B4