Mains Connection; Operation - Zeck PT Série Mode D'emploi

The pin configurations for the three speaker connectors are
printed on the amplifier's back panel. The speaker outputs are
wired so they can be used in different ways depending on the
setting of the mode switch. Before connecting the speakers,
make sure that your speaker cables are wired accordingly.
DUAL mode: use the SPEAKER OUT 1 and 2 outputs to
connect the speaker systems.
The BRIDGED OUT also carries both output signals and can
be used to feed the output signal to an additional device, e.g.
feedback for speaker system processor. Minimum total speaker
impedance per channel is 2 ohms.
Pin configuration for Speakon plugs
Dual (Stereo) Mode / Parallel Mode:
Speaker Out 1
(may also be used as 4-pole stereo output)
2+
2–
+ –
2
1
1–
– +
1+
Bridged Out
(feedback for optional processor)
channel 1 ground
2+
channel 2 signal
channel 2
ground
1–
2–
1+
channel 1 signal
PARALLEL mode: same wiring as DUAL mode, but with identi-
cal signals on all outputs. Minimum total speaker impedance
per channel is 2 ohms.
BRIDGE mode: BRIDGED OUT speaker connection is done by
using standard speakon cables. Make sure that there is no
ground connection for pins 2+ and 2– on your Speakon plug.
The OUT 1 output socket can be used to feed the output signal
to an additional device, e.g. feedback for speaker system pro-
cessor.
Pin configuration for Speakon plugs
Bridge Mode:
Bridged Out
(feedback for optional processor)
2+
2–
–
1–
+
1+
seen from solder side
of plug

2.3.3 Mains connection

For mains connection, use only three-prong mains connectors
with earth contact. Switching the amplifier to different voltage
systems is done from the inside and should be performed only
by a qualified technician.
The mains cable conductors have the following color code:
YELLOW / GREEN = earth (PE)
BROWN = live (L)
BLUE = neutral (N)
owner`s manual PT series © 1995 Zeck Audio
owner's manual PT series

3. Operation

Each channel is controlled from the front panel by one level
control potentiometer and 4 status LEDs. The status LEDs indi-
cate the following operational states of the amplifier:
• READY/PROTECT: this two-coloured LED indicates the state
• SIGNAL: a lit LED indicates an audio signal present at the
Speaker Out 2
2+
• NLR: lights up when the internal limiter needs to automatical-
2–
–
2
1–
+
1+
seen from solder side
of plug
• TCL: indicates signal limiting as a result of heatsink
The following diagram illustrates the actions taken by the ther-
mal management system:
Speaker Out 1
signal –
2+
2–
1–
1+
signal +
of the output protection relay. It lights up green when the
amplifier is working normally and turns red, whenever the
output is disconnected internally as a result of malfunction,
e.g. dc voltage at the output, output stage defect or heatsink
temperature exceeding 90°C. After turning the amplifier on,
this LED will remain red for about 5 seconds until the internal
supply voltages have set to their normal values.
channel's output. Threshold level is +10 dBV.
ly reduce gain beause of a significant deviation between input
and output signal shape. This way, the NLR limiter prevents
occurance of gross non-linearity conditions inside the
amplifier, caused by overdrive, overload or defect, and keeps
the signal shape unaltered under any cicumstances. The
NLR circuit keeps signal shape distortion under 5% and
thus guarantees for a clean sound and effective speaker
protection.
overtemperature (above 80°C). This helps to prevent
triggering of the internal thermal shut-off circuit, which would
step in at 90°C heatsink temperature as a final safeguarding
measure. The TCL circuit becomes only active when the
regular cooling mechanism fails to work properly, e.g. by a
dirty heatsink. A lit TCL control LED should always be taken
as a sign to check for sufficient cooling air supply.
Heatsink temperature
Automatic
speaker re-
60°C Max. fan speed
connection
at 75°C
Fan speed temperature control-
led, TCL inactive
Min. fan speed,
TCL inactive
90°C output
relay disconnects
speakers
80°C TCL active
Amplifier: Zeck PT
13