McIntosh MC 225 Service Manual

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McIntosh MC 225 Service Manual

Extracted text from McIntosh MC 225 Service Manual (Ocr-read)


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Table 1. MC225 VOLTAGE AND RESISTANCE CHART (Schematic No. SC126-167A) Tube 12AX7 (VI) 12AU7 (V2 or V3) 12BH7 (V4 or V5) 7591 (V6, V7, V8, or V9) Pin No. 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 DC Volts 115 0 1 FIL FIL 115 0 1 FIL 295 115 121 FIL FIL 295 100 121 FIL 285 25 39 FIL FIL 285 25 39 FIL FIL 390 390 0.8 -21 FIL 390 Resistance in Ohms, Unit Off 180K 1M 3.3K 0 0 180K 1M 3.3K 0 27K* 180K 18K 0 0 30K* 2.4M 18K 0 22K* 220K 4.7K 0 0 22K* 220K 4.7K 0 0 62* 130* 40 180K 0 130* This Resistance measured to positive side of B+ rectifier SR2. Warning: Discharge filter condensers before making measurements. A high resistance VTVM is used for all measurements, voltages and resis- tances are to ground except as noted.