ALLNIC AUDIO A-2000 MK3 Benutzerhandbuch - Seite 8
Blättern Sie online oder laden Sie pdf Benutzerhandbuch für Verstärken ALLNIC AUDIO A-2000 MK3 herunter. ALLNIC AUDIO A-2000 MK3 14 Seiten. Kt170 push-pull stereo power amplifier
Seite druckenOPERATION
When the power is on, the current meters on the top plate of the chassis will illuminate. From this point on,
operation is straight-forward. When you are finished listening, turn off your A-2000 MK3's power first; then, turn
off your preamplifier and sources.
the speakers as the amplifier's relays turn off. Though this sound is harmless to speakers, some users may prefer
not to hear it. To avoid the sound, simply switch the A-2000 MK3 to pentode (beam tetrode) mode prior to
turning it off (see the "On-the-Fly Triode/Pentode Switching section below).
In the case of any failure, please contact your Allnic dealer for assistance.
"ON-THE-FLY" PENTODE/TRIODE SWITCHING
You can use the Pentode/Triode "Mode Selector" button at any time during operation to switch back and forth
from Pentode to Triode operation. Press the mode selector button on the left side of the front panel down to
have the A-2000 MK3 operate in Triode mode; press the button again so it is in the raised position to have the A-
2000 MK3 operate in Pentode mode (See Figure 5).
THE CURRENT METERS
The illuminated meters on the chassis' top plate indicate the current supply to each of the four KT170 gain tubes in
the A-2000 MK3 (See Figure 6). There is one current meter for each channel's pair of KT170 power tubes. These are
switched between tubes in each pair by using the small switch between and to the outside of each KT170 pair. There
are also a potentiometer (yellow bias control screw) and a fuse for each KT170.
After soft-start and sufficient warm up of the A-2000 MK3, the needle of each current meter should be centered
between the two parallel lines on the meter face. Any error of current supply to or failure of a KT170 tube is
indicated by the needle on the KT170 tube's respective meter moving out this position and even a small distance out
from between these two parallel lines. Re-centering the needle between the lines on the meter face to achieve
proper bias may be required from time to time. See below.
TUBES AND TUBE BIAS
The A-2000 MK3 Stereo Power amplifier uses the following tubes:
• Four (4) x KT170
• Four (4) x 6S4
• Two (2) x 5654
Because of the individual bias for each KT170, it is not necessary to use a matched quad of these power tubes in the
A-2000 MK3.
As mentioned above, there is a switch on the top plate of the chassis between and to the outside of each of the left
and right channel pairs of KT170s (See Figure 6). Flipping the switch toward the rear of the chassis sets the meter to
read the rear KT170 for that channel. Flipping the switch toward the front of the chassis sets the meter for the front
KT170 for that channel. As noted above, the needle of the meter should always be centered between the two
parallel lines in the center of the meter. The position of the needle should be the same for all four KT170s. You may
adjust the needle's position by turning the relevant yellow potentiometer screw clockwise or counter-clockwise
using an appropriately bladed screwdriver. The position of the needle between the lines will alter the sound.
If the A-2000 MK3 is in triode mode at turn-off, it will produce a sound through
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