User manual SMART DEVICES HF100 SCHEMATIC DIAGRAMS

[. . . ] For service or installation assistance, please call our Technical Support Department between the hours of 8 a. m-5 p. m. 1-800-45-SMART LIMITED WARRANTY: SMART products and accessories are warranted against malfunction or failure due to defects in workmanship or materials for a period of one year from the date of shipment. If a problem occurs during the warranty period, the unit will be repaired, or replaced at our option, without charge for materials or labor. If air freight is requested by the dealer, the difference between air and surface charges will be billed to the dealer. [. . . ] EQUIPMENT REQUIRED: Sound Pressure level meter, real time analyzer with a calibrated microphone, dual trace oscilloscope, multimeter, a tuning wand and appropriate test loops. B CHAIN CALIBRATION: PRELIMINARY: It is desirable to have a SMART PINK NOISE GENERATOR CARD and, optionally, an EXTENDER CARD for performing the calibration and testing of the HF100. Note: Make sure the SMART Pink Noise Generator Card has the following minor modification: There must be a jumper wire between pins 4 & 5 of the edge connector as viewed from the component side. This allows the Surround switch to simultaneously feed pink noise to both Left and Right Surround channels. A future version of the Pink Noise Generator card will have separate Left and Right Surround switches. The PINK NOISE card may be plugged directly in without the extender card, but it is easier if the extender card is used with the PINK NOISE card. The PINK NOISE card plugs into the MATRIX CARD position for setting house EQ levels and into the PREAMP CARD position for setting subbass levels. The bottom switch is used to select NORMAL or CHOOCHOO modes. The top six switches are used to turn individual channels on and off. These channel switches are three position, with center position being off, the top position giving an in phase signal and the bottom position giving an out of phase signal. There is a built-in high quality pink noise source which feeds these switches. If more gain is needed, then the gain pot on the 10 INSTALLATION & OPERATION stage EQs can be used which gives an additional 6 dB of gain. However, do not boost the gain on the EQ cards unless it is absolutely necessary. The 1/3 octave stage channel equalizers in the HF100 allow the same tuning results obtained in professional room tuning filter sets used in high-end sound playback applications. Sound contractors learned, a long time ago, that boosting frequency bands adjacent to bands that are cut introduce a phase shift that the ear is very sensitive to. Although the test instruments show a nice curve, the sound has a coloration that is not natural. For this reason, we encourage you to apply the minimum amount of boost and cut whenever needed. All frequencies may be cut and boosted by as much as 7 dB in each of the 1/3 octave bands without creating the above problems. The use of bass and treble controls on the equalizer has also been avoided to further minimize phase shift. Each filter section uses a single turn trimpot for adjustment. The equalizers are factory set for flat response during final QC test. Before attempting to equalize be sure the stage speaker connections are properly polarized, the polarity of the components in each speaker system is correct, and the speaker devices are mechanically aligned according to the manufacturer's recommendations. [. . . ] If the relative humidity is below 50%, use a grounded workbench and make sure that the PC board is grounded to it. To prevent static damage to a chip, do not touch any of the leads unless you are also touching the workbench, or you are connected to it through a standard high-resistance grounded wrist strap. (Such wrist straps are connected to ground through a 1 megaohm or more resistor, greatly reducing danger to personnel due to electric shock. ) Other components that are soldered in place may be replaced following the instructions covered in this section. If filter capacitors are to be replaced, fasten them securely to the board using the original factory installation as a model. [. . . ]