Anthem Audio Amp 1 - Manual (Page 6)

The Amp 1 comes with seven (7) tubes, as follows:
12 AX7 (V2) FIRST S TAG E AMPL IF ICATION TUBE
The first stage of amplification in the amplifier section of
the Amp 1 is achieved through the use of this dual triode,
amplifying both channels, one per triode section. The
12AX7 may be replaced with the ECC83 or 7025A tube.
12 AU7 (V1 & V3) D RIVE R TUBES
These tubes split the phase of the signal and drive the
push/pull pairs of power tubes. The 12AU7 tubes may be
replaced with ECC82, E82CC, ECC802S, 5814A, 6189,
CV4003 or M8136. 12BH7A tubes may also be used with a
slight increase in performance.
EL34 (V4,V5,V6,V7) PO WE R TUBES
These tubes provide the last stage of amplification, set up
in push/pull pairs (2 tubes per channel). The output stage
uses an adjustable fixed biasing scheme which has been
carefully adjusted at the factory to match the characteris-
tics of the output tubes shipped with this unit. The Bias
adjustments should remain reasonably stable over the life
of the output tubes and should not require periodic adjust-
ment until the EL34 tubes are replaced.
Should one of the EL34 tubes fail, it may be replaced indi-
vidually, as separate bias adjustments allow optimizing the
operating conditions for each tube. For best performance,
tubes in the pair V4 and V5 or V6 and V7, should be
replaced with a matched pair. EL34 output tubes are inter-
changeable with and may be replaced by 6CA7, E34L, and
KT77. Other tube substitutions are not recommended.
WARNING: Tube replacement and bias
adjustment involves working with the
covers off and power applied, around
hazardous and potentially lethal voltages,
and should be performed only by quali-
fied personnel with the proper equipment
and training.
4
S E T T I N G U P
Left Channel
Output Transformer
Right Channel
Output Transformer
Left Channel
Output Binding Posts
Right Channel
Output Binding Posts Right Channel
RCA Input (SE)
Right Channel
RCA Input (SE) AC Power Inlet
Fuse Holder
Power
Transformer
ON/OFF
Power Switch
Biasing Controls Biasing Controls