Audial A20 User manual

A20
STEREO AMPLIFIER
USER MANUAL
Revision 0, September 2021

IMPORTANT!
1. This manual is a guide only.
2. Do not expose this device to rain or moisture, excessive heat, or mechanical force.
3. Use this device exclusively with specified voltages.
4. Unplug the device from the wall outlet during a lightning storm.
Copyright © 2021, Audial d.o.o.
www.audialonline.com
This manual comprises introducing information on the use and performance of this device.
For more information, please visit https://www.audialonline.com/a20/, or send your questions to
[email protected].

!
The lightning flash with arrowhead symbol within an equilateral triangle is intended to alert the
user to the presence of uninsulated “dangerous voltage” within the product’s enclosure that may
be of sufficient magnitude to constitute a risk of electric shock to persons.
The exclamation point within an equilateral triangle is intended to alert the user to the presence of
important operating and maintenance (servicing) instructions in the literature accompanying the
product.

STARTING WITH THE A20
A20 stereo amplifier is relatively simple to use and,
provided it is used within its limits, it requires no special
care in everyday operation.
It achieves claimed specifications right from the start,
even though it still needs 5-7 days of burning in to
perform its best in the subjective audio terms.
Afterward, it is generally enough to leave it powered
on for half an hour before the critical listening.
It is not harmful if A20 is left constantly powered on,
however a general recommendation to turn such
devices off whenever out of home applies regardless.
Also, it is important not to block the opening holes at
the bottom, back and top plate, as they provide the air
circulation into and from the unit interior, and thus
ensure the proper cooling.
CONNECTIONS
No special knowledge is required to connect the A20
into the system.
Mains connector is standard IEC C14, and is located at
the back panel. Every unit is produced to match the
mains voltage in the customer’s country.
There are five RCA line input connectors, and its
impedance is 45 kOhm, so the A20 is a friendly load for
the majority of sources.
The A20 employs a buffered pre-out, which can be
useful for bi-amping, or to connect the active
subwoofer.
The output loudspeaker connectors are Audial made
pure copper binding posts, which accept the usual 6.3
mm spades or 4 mm banana plugs.
The A20 does not invert polarity (absolute phase).
Hence with the source which also does not invert
polarity, the speakers should be wired in phase, so the
ground connection to the negative pole, and hot (live)
connection to the positive pole.
USING THE A20
Apart from the mains switch, the A20 has only one
control knob, which is both the volume and balance
control, and the input switch, while the amplifier
setting is shown by the display.
Normally, the volume is set by rotating the knob. The
volume is set in 1 dB steps, and has the "mute", and 63
steps between the 0 dB and maximum position.
The input is set by pressing the knob.
By long pressing the knob (for 2 seconds), the amplifier
enters the balance menu. The display, instead of the
volume position, in its second row then shows the
balance position. The balance can be set in 1 dB steps
(32 dB is maximum). By another long pressing (again
for 2 seconds) the knob, or by its inactivity for 5
seconds, the knob will go back to the regular volume
control operation. If the balance is set out of center, the
notice will remain on the right side of the upper row of
the display.
WARRANTY
Audial claims the proper operation of this product for
two years. Audial is obliged to correct for any
malfunction within this period, at no charge, either by
the competent repair service, or by swapping the sold
unit with the new one.
For the units sold directly by Audial, the invoice is also a
guarantee certificate. Audial however maintains its
database of directly sold units, so the original buyers
will not usually need it. Warranty is also fully
transferrable from the original to the subsequent
owner(s), however in this case we will probably ask for
the invoice.
5
Audial A20

6Audial A20
A20 back plate
From left to right:
Pre-out, line inputs, loudspeakers outputs, mains connector.
AMPLIFIER A20
VOLUME
POWER
!
AMPLIFIER A20
# A01-xx21
MADE IN SERBIA
22 40-2 0VAC
50-60Hz
FUSE T3 A.15
SPEAKERS
INPUTS HOT
GND DO NOT OPEN!
RL
1
2
3
4
5
PRE-OUT
R
L
R
L
A20 front plate
From left to right:
Power switch, display, control knob.

7
Audial A20
SPECIFICATIONS
INPUT VOLTAGE:
Min 0.5 V RMS for full power
Max 5 V RMS (input overload)
INPUT IMPEDANCE:
45 kOhm
OUPUT POWER:
20 W RMS @ 8 or 4 Ohm
MAXIMUM OUPUT CURRENT:
3 A, continuous
FREQUENCY RESPONSE:
20 Hz - 200 kHz, ±0.5 dB, typical
The amplifier is directly coupled, but its gain is blocked for DC, for loudspeakers safety
HARMONIC DISTORTION (@ full power):
0.01% @ 1 kHz @ 8 Ohm
0.02% @ 1 kHz @ 4 Ohm
0.03% across the audio band (worst case) @ 8 Ohm
0.06% across the audio band (worst case) @ 4 Ohm
INTERMODULATION DISTORTION (@ full power):
0.03% @ 8 Ohm
GAIN (max gain between the input and speakers out, and also the ratio between the pre-out and speakers output):
31.3x (29.9 dB)
PRE-OUT GAIN:
1x (0 dB) @ max position
PRE-OUT IMPEDANCE:
130 Ohm
ABSOLUTE PHASE:
Correct, for both the loudspeakers and pre-out
MAINS VOLTAGE:
220-240VAC/50-60Hz, or 110-120VAC/50-60Hz, or 100 VAC/50-60Hz
DIMENSIONS (W x D x H):
426 x 280 x 92 mm, including feet, but excluding the knob and connectors
WEIGHT:
Approx. 6Kg

Copyright © 2021