[. . . ] If you do not intend to use your unit for any considerable length of time, turn the unit off completely by pressing the round Power button above "Power" (see page 5). Do not place furniture or other heavy objects on the cord, and try to avoid dropping heavy objects on it. Not only may the cord be damaged, it can also cause a short circuit with a consequent fire hazard. [. . . ] However, ordinary copper wire can be used if the gauge meets the following requirements: Wire Length Up to 2. 5 meter Up to 4 meter Up to 6 meter Above 6 meter Min. Diameter 1 mm 1. 25 mm 1. 6 mm 2-2. 5 mm IMPORTANT: When connecting two pairs of speakers, determine the impedance of each pair by looking on the back of the speakers, in your owner's manual, or by contacting your dealer or manufacturer. You can listen to two pairs of speakers at the same time ONLY if the impedance of EACH speaker is NOT LESS THAN 8 Ohms. WARNING: Do not play sets of speakers simultaneously except as recommended above. Digital Loop-Through Digital inputs and outputs are provided only as a convenience for connecting various digital components to the "CD", "CDR" and "AUX" digital inputs. The corresponding digital input signal is fed to the "DIGITAL OUT" connector when "CD", "CDR" or "AUX" is selected as input source, to provide a digital signal for CD or MD Recorders. Avoid rolling excess wire with or near signal interconnects. 4 CONNECTIONS Controls and Functions HK 670 Power switches Press the round Power button (above "Power") to turn the amplifier on for the first time. The status LED behind the flat "Power" button will turn orange. Once the unit has been turned on with the round power button, this button should be left on for normal use and only turned off when the amplifier will not be used for extended periods of time (vacation, etc. ). For daily use, press the flat "Power" button to turn the amplifier on or off (Standby). In Standby the LED will glow orange, indicating that the unit is still connected to AC mains and can be turned on from the remote control or with the flat "Power" button. Headphone Jack Plug in headphones if desired. With both "Speaker 1" and "2" selectors in the Off position, output is supplied only to headphones. Speaker 1 / 2 Selectors Press to select speaker pair 1 or 2, or both, or neither (headphone output only). Input Source Selector Select desired input source for listening by pressing the "Input Source" button repeatedly (on the left will select upwards, right downwards) until the indicator for the desired source is illuminated. Record Source Selector Select desired source for recording to device connected to the rear panel Tape and CDR Out sockets by pressing the "Record Source" button repeatedly until the indicator for the desired source is illuminated. Bass Control Turn to increase or decrease the amount of low frequency sound. Treble Control Turn to increase or decrease the amount of high frequency sound. [. . . ] · The balance control knob is set to the center. Sound is not heard from the speaker system on one side. When listening to stereo sound, the left and right sounds are reversed. The remote control and front panel controls don't appear to work. Humming noise when listening to LP Howl or ringing when listening to LP. [. . . ]