zapco PX Owner's Manual
          | |
Input Gain AdjustmentThe pre-amp circuit built into the PX is capable of 26dB of gain.Separate left and right channel INPUT GAIN adjustments aremade via two access holes in the lower left hand corner of thefront panel. Adjustments to the INPUT GAIN may be necessaryto match the source (TAPE DECK, TUNER, OR CD) output levelto the input sensitivity of the system amplifiers. If this adjustmentis set too low, the source may distort before the system is able toachieve full power. If the INPUT GAIN is adjusted too high, theinternal circuitry of the PX and/or system amplifiers may distort.Three OVERLOAD indicators located on the front panel of the PXare supplied to aid in the gain adjustment procedure. Each ofthese are WARNING indicators and should NOT illuminate withany degree of regularity once the system gains have beenproperly adjusted. The red indicator labeled PRE is calibrated toilluminate when the internal circuitry of the PX is within 1dB ofclipping. The yellow indicators labeled LO & HI are calibrated toZAPCO power amplifiers with an input sensitivity of 2.5V RMS andindicate the onset of amplifier clipping.Insert tape or compact disc recorded at high level into the sourceunit. If the source unit has a balance control, ensure that it is setto center. Set the PX filter controls flat (white strip on controlknobs completely vertical). Using a small plastic screw driverincluded with the PX adjust the INPUT GAIN trim pots fullycounterclockwise. These trim pots are 20 turn pots and willratchet at the end of their throw. Turning each pot more than 20turns counterclockwise (or until ratcheting can be heard) willensure that left & right channels are matched before the gainadjustment procedure begins. If the source has a volume control,set it from approximately 1/2 to 3/4 full output. With the PXvolume control rotated completely counterclockwise, begin byturning only one INPUT GAIN pot clockwise (count the number ofturns) until PRE indicator flashes, rotate 1 to 2 turnscounterclockwise or until flashing ceases. Rotate the other INPUTGAIN trim pot the same number of turns as the first. Turn up the6 |
Related manuals for zapco PX
This manual is suitable for:
manualsdatabase
Your AI-powered manual search engine