Power Indicator; Protection Systems; Drive Protection; Transformer Thermal Protection - DIGISYNTHETIC DP Series User Manual

4. Do not short the ground lead of an output cable to the input signal ground. This will
form a ground loop and may cause oscillations.
5. Do not operate the amplifier from AC mains in excess of 10% variation above or below
the selected line voltage, and only at the specified line frequency.
6. Never connect the output to a power supply output, battery or power main. Such
connections may result in electrical shock.
7. Tampering with circuitry by unqualified personnel or making unauthorized circuit
changes may be hazardous and invalidates warranty.
Remember DIGISYNTHETIC Audio INC., is not liable for any damage that results from
overdriving other system components.

5.2 Power Indicator

When illuminated, the green power indicator (the volume control) shows that the
amplifier has been turned on. It is driven only by the low-voltage power supply and
does not indicate the status of the high-voltage supply.
5

.3 Protection Systems

DP Series amplifiers have extensive protection systems, including TPC, protection,
drive protection, transformer thermal protection, and fuses or circuit breakers that
protect the power supplies.
5

.3.1 Drive Protection

The Drive Protection System temporarily removes output drive to protect the
amplifier and its loads. Drive Protection System can be activated in two situations.
First, if dangerous subsonic frequencies or direct current (DC) is detected in the
amplifier's output, the unit will activate its DC/low-frequency protection circuitry, which
puts the amplifier in Drive Protection mode. This mode protects the loads and
prevents oscillations. The unit resumes normal operation as soon as the amplifier no
longer detects dangerous output. Although it is extremely unlikely that the DC/low-
frequency protecti-on system will ever be activated, improper source materials like
subsonic square waves or input over-loads, that excessively clip the input signal, can
activate this system.
The amplifier's protection system will activate the amplifier's Drive Protection mode
in rare situations where heavy common-mode current is detected in the output. The
unit should never output heavy common-mode current unless its circuitry is
damaged. Activating Drive Protection mode helps prevent further damage.
5.3.2

Transformer Thermal Protection

All DP Series amplifiers have Transformers Thermal Protection. This protection is
activated in unusual situations where the unit's transformer temperature rises to
unsafe levels. Under these abnormal conditions, the unit will removes output drive
to protect amplifier.. The fan will continue to run in all units. The amplifier will return
to normal after it cools to a safe temperature. I
amplifier will ever activate its Transformer Thermal Protection as long as it is
operated within rated conditions.
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t is very unlikely that your DP Series