ALLNIC AUDIO A-2500 Руководство пользователя - Страница 9
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To bias the power tube properly by centering the meter's needle between the meter's main parallel lines,
use an appropriately bladed screwdriver to adjust the bias control directly in front of the 211/845 by
turning the yellow plastic screw clockwise or counterclockwise. If the needle of a current meter for the
211/845 has moved to the left of the parallel lines on the meter's face, adjust the bias control by turning
the plastic screw clockwise until the needle has returned to centre between the meter's parallel lines. If
the meter needle has moved to the right of the parallel lines on the meter face, turn the bias control
counterclockwise to correct.
If the meter's needle drops to the left limit of the meter's face during operation, this indicates a failure of
the related 211/845 tube. You must turn off the A-2500 and replace the 211/845 and, probably, the
protection fuse (0.5A, 250V, 20mm slow-blow) for the tube. To replace the fuse, using a screwdriver,
simply turn the top of the fuse cap (located just behind the 211/845 tube – see Figure 4) counterclockwise.
It will spring out holding the fuse. Replace the fuse, push the fuse cap down and turn it clockwise; it will
lock itself. If you have any questions about doing this, please contact your Allnic dealer for assistance.
If the 5.0 Amp AC mains fuse, located at the IEC input, has failed, it can be replaced with the spare fuse
provided in the tray in the IEC mount. Again, if you have any questions about doing this, please contact
your Allnic dealer for assistance.
Of course, you will have to adjust the bias back into the area between the two parallel lines of the meter
for a tube when it is replaced. When replacing a 211/845, first turn the bias control counterclockwise
slightly to reduce current, in case the bias is set too high for the new tube (since the old tube may have
required additional bias). Bring the bias up gradually to the middle between the two lines on the meter.
All consequences of changing or attempting to change tubes are borne by the user unless by express
agreement between the owner and an authorized Allnic representative. Allnic Audio and its authorized
representatives are not liable in any way whatsoever for any injury or loss incurred by the user or for
damage to the A-2500s, any of their parts, or tubes or replacement tubes resulting from the user
changing or attempting to change tubes.
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