Owner's Manual
Table Of Contents
- Owner's Guide
- Table of Contents
- Important Safety Instructions
- Introduction
- Unpacking Your HINT 6 & Placement Guidelines
- AC Mains Voltage Selection and Fuse
- Analog Audio Input Connections
- Theater Bypass / Amp Input
- Digital Inputs: OPT 1, OPT 2, COAX, USB
- USB - Computer Setup
- Audio Output Connections
- Other Rear Panel Connections
- Subwoofer Setup
- High and Low Pass Crossover Setup
- Front Panel Controls
- Remote Control Functions
- Turn On Volume & Favorite Volume Settings
- Power Amplifier Stage Protection Circuits
- Problems and Remedies
- Assistance or Warranty Repair
- Specifications
21
Power Amplifier Stage Protection Circuits
The HINT 6 protects itself from external fault conditions such as excessive heat, load impedance
that is too low, or a short-circuited speaker connection or wire. Under such conditions the On-Off
button will glow red. After you correct the fault, the HINT 6 will resume operation and the On-Off
button will glow blue.
Current Overload (short circuit or load impedance below 1 ohm)
Specialized current sensors constantly monitor the current flow through the HINT 6's output
stage transistors. If the current draw exceeds a predetermined safe level due to a load
impedance below 1 ohm or a short circuit at the speaker terminals, the output protection relay
will open immediately to prevent damage to the output transistors or other parts. This will
cause the On-Off button to glow red. Immediately turn off the HINT 6 and disconnect the
speakers from the Integrated’s speaker terminals. Turn the unit back on to see if the On-Off
button now glows blue, indicating the fault has been removed. Carefully check your speaker
wires and speaker connections for a short circuit and correct the problem before attempting to
resume listening.
Overheating Condition
If the unit overheats the On-Off button will glow red and the power amp section will shut down.
If such a condition occurs you must provide better ventilation around the amplifier. The over-
temperature protection can also be activated if you are trying to drive more than one pair of
speakers for an extended time and/or at extremely high listening levels. If the protection
circuit has been activated because of overheating, normal operation will resume after the unit
has cooled down.
DC Servo Protection
The HINT 6 power amp stage is direct (DC) coupled from its input to its speaker terminals.
Since direct current (DC) burns out speakers every power amplifier must have some way to
ensure that DC never reaches the + or - speaker terminals. Most amplifiers simply use
capacitors to block DC from another component or internal trim controls which a technician
(only) can adjust to reduce DC offset. Unfortunately, trim controls can allow DC offset to creep
up over time, and even the most expensive capacitors in the audio signal path attenuate bass
response, placing a “veil” between you and your music.
Parasound power amplifiers overcome this problem by incorporating ingenious and fast-acting
DC servo circuits that monitor the audio signal (but are not actually in the audio signal path) to
keep DC offset at the HINT 6 output close to zero, without using coupling and blocking
capacitors. This advanced circuitry never needs adjustment or maintenance and the results
are startling clarity, freedom from listening fatigue, and formidable bass response.
Faulty source components and particularly vacuum tube preamps with leaky output coupling
capacitors can have a large DC offset in their outputs that exceeds the capabilities of the DC
servos. In this case the protection circuit will activate. If the HINT 6 On-Off button glows red,
try disconnecting your source components after trying the other two steps listed above.
Contact Parasound
If you believe you have confirmed the above three fault conditions are not present and the On-
Off button still glows red it could indicate an internal problem. Please contact Parasound’s
Technical Service Department.