Harman Kardon A250 Owners Manual - Page 9

auxiliary input jacks. TUNER selects your monaural tuner for operation and PHONO selects either your magnetic or ceramic cartridge. TAPE HD selects your tape deck. Speaker Selector Switch: In a monaural installation where more than one set of speakers are installed (for example: one speaker in the living room and another in the den) selection between the two speakers is made by operating the SPEAKER SELECTOR switch on the front panel. To operate Speaker A (located in your living room ) set the upper SPEAKER SELECTOR switch located on the front panel to "A", and the lower SPEAKER SELECTOR switch to "One". To select Speaker B (located in another room), set the upper SPEAKER SELECTOR switch to "B" and the lower SPEAKER SELECTOR switch to "One". To operate both speakers simultaneously, set the upper SPEAKER SELECTOR switch to either "A" or "B" and set the lower SPEAKER SELECTOR switch to "ALL". Rumble Filter Switch: At times, record changers, turntables and even some FM stations produce an objectionable low frequency signal that is strong enough to be introduced into the sensitive playback system. Known as "Rumble", this undesirable signal can be eliminated by the RUMBLE FILTER switch incorporated in the Model A-250. Whenever rumble is encountered, set the switch to "ON". Scratch Filter Switch: In the event of objectionable high frequency record scratch throw the SCRATCH FILTER switch to "ON". This will roll off the higher frequencies. Equalization Switch: In order to assure good reproduction of the wide range of frequencies in music and to make necessary adjustments for the limitations of the recording technique, record manufacturers have found it necessary to modify the actual frequency response of the music while it is being recorded. Thus, to avoid overcutting and consequent distortion, a measured and deliberate reduction is effected in low frequency response by selecting a "turnover frequency" and by recording attenuated response below that point. To assure optimum signal-to- noise at the high frequency end when the record is played at home, the highs are deliberately exaggerated during the recording process. A measured and deliberate boost is effected above a certain frequency. This combination of deliberate exaggeration at the low and high ends of the frequency response can be expressed in a "recording curve". When the record is played a mirror image of that curve should be available so that the ideal "flat" response may be achieved. Since several different recording curves have been used in the past (differing with respect to the turnover points and the degree of emphasis or de-emphasis) a choice of playback curves is provided in Harman-Kardon instruments. Monaural records usually indicate the correct equalization setting on the jacket. Follow the record manufacturer's recommendation as to the exact setting. However, it should be noted that it is not compulsory to adhere strictly to the recommendation. For example: Capital records are recommended to be played on the "RIAA" equalization curve, but if for some reason (room acoustics, speaker location, type of program source) the sound is not quite satisfactory, it is permissible to change the equalization control setting to "EUR". If the overall sound quality pleases you more, leave it that way. Your hearing should be the final judge as to the exact equalization control setting. For monaural tape playback set the control to the appropriate tape speed. This automatically compensates for the tape equalization.