User manual TAG MCLAREN AUDIO PA20R

[. . . ] A separate signal path is provided for recording, with its own independent input selector, so you can record one piece of music while listening to another. The microprocessor-controlled relay switching system in the PA20R The theoretically-ideal preamplifier reproduces sound perfectly over an infinite range of frequencies ­ starting from well below the audible range and extending far above the capabilities of human hearing. Although sound outside the human hearing range of approximately 20 to 20, 000 Hz cannot be heard, it can significantly distort the quality of music reproduction through an effect that audio engineers call `intermodulation distortion'. This type of distortion moves imperfections that originate outside the hearing range back into the audible frequencies. To minimise this effect, TAG McLaren Audio preamplifiers have a frequency response which extends 05 welcome welcome both above and below the range of normal human hearing. straight line technology time constant switching control of volume and gain To prevent intermodulation distortion, a preamplifier must respond to very low frequencies but block any Direct Current (DC). This is traditionally achieved using capacitors, which also block some of the lowfrequency signal. In the PA20R, a feedback circuit eliminates DC offset voltage and allows the signal path to be direct coupled without any capacitors. This arrangement, which we at TAG McLaren Audio call `Straight Line Technology', is easy to describe but not easy to realise. The design has taken our expert engineers years to perfect. The PA20R has a sophisticated muting system which protects your hi-fi and prevents annoying, loud switching noises from reaching the output. A preamplifier that responds to low frequencies will `ring' for a long time in response to the sudden voltage changes that happen, for example, when you select a different input. [. . . ] Make sure that nothing interferes with the free movement of the knob when you use the remote control Muting protects your PA20R, your amplifier and your loudspeakers and prevents unpleasant switching noises upsetting your listening experience 1. OUTPUT 3 is only functional if your PA20R has been fitted with the optional transformer-coupled and balanced output. See page 19 for details 3. 14 15 gain control headphones choosing the best gain setting Turn the GAIN selector to select a gain setting. Gain is the amount of preamplification that the PA20R applies to the input signal. It is shown in dB(1). GAIN headphone connection Turn the VOLUME down before you connect your headphones. Insert the headphone plug into the 1/ (6. 3 mm) stereo jack socket 4" on the front panel of your PA20R(1). Start with the GAIN selector in the middle of its range at 9 dB. Play some music with roughly average dynamics and adjust the volume to suit your normal listening. If the VOLUME knob is near the low end of its scale, decrease the GAIN. Choose a GAIN setting which allows the VOLUME knob to sit nearest its middle position. To avoid excessive sound levels from, and prevent damage to, your loudspeakers, you should reduce the volume before you turn up the gain. You may find that the best setting for headphones is different to that for your power amplifier and loudspeaker combination. 0dB 3 6 9 12 15 dB loudspeaker muting When you plug in your headphones, OUTPUT 1, 2 and 3(2) are automatically muted. 1. dB (short for decibel) is a logarithmic scale of the ratio between input and output. A step of 3 dB is equivalent to a factor of two in output power, and the human ear perceives 10 dB as an approximate doubling of the sound level If you want to use headphones which have the smaller 1/8" (3. 2 mm) jack plug, you should obtain an adaptor from your retailer. Remove the adaptor from the socket when you are not using the headphones or the output will remain muted OUTPUT 3 is only functional if your PA20R has been fitted with the optional transformer-coupled and balanced output. See page 19 for details 2. 16 17 grounding outputs The AC mains supply normally operates at either 50 or 60 Hz (depending on which country you are in). Under some circumstances, this can cause an audible hum in your loudspeakers. Should you have any problems with hum in your system, please contact your retailer. The audio outputs are intended to connect the PA20R to one or more power amplifiers (such as our 60P, 100P or 125M). The low-impedance (100 ) output is buffered and will drive long cables or several inputs in parallel if required. audio output sockets OUTPUT 1 and 2 each consists of two phono sockets on the back panel of your PA20R, one for the left channel and one for the right(1). Always use high-quality, screened cables for your connections. OUTPUT 2 1 left left avoiding hum To minimise the possibility of mains hum in your system: do not link the ground terminals of separate audio units together. use screened cable for your signal connections and keep the left and right channel cables close together. right right grounding your system All the units in the TAG McLaren Audio F3 Series are double insulated and do not require safety ground connections. Although a ground terminal is provided on the PA20R, for your convenience your system does not need to be connected to ground (audio engineers call this `floating'). However, if you want to ground your system, please contact your retailer who will be able to assist you. ground 1. OUTPUT 1 and 2 are connected together in parallel 18 19 outputs connecting power amplifiers OUTPUT transformercoupled, balanced audio output (option) As an option, the PA20R can be fitted with transformers to provide a balanced output via XLR connectors. [. . . ] There are no other user-serviceable parts inside the PA20R. service The only service you should do to your PA20R is described on the left. All other servicing should only be carried out by one of our authorised service agents. If service is required, please contact your authorised TAG McLaren Audio retailer. If your PA20R is still under guarantee, please refer to the guarantee card which gives you details on how to claim against the guarantee. [. . . ]