WhitakerAudio 60 W Stereo Power Amplifier, User And Assembly Manual

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WhitakerAudio
7) If any deviations from the expected values listed in Table 6.1 are observed, recheck wiring
and components for correct installation. Do not advance to the next step until the resistance
measurements for the power supply are within tolerance.
8) Using an ohmmeter, confirm that the resistance values listed in Table 6.2 are observed on
the tube socket connections for the right channel amplifier and then for the left channel
amplifier. All readings are with reference to ground. Readings within ±5 percent are
considered normal.
Table 6.2 Typical Amplifier Circuit Ohmmeter Readings with Power Removed
and Tubes Removed
Tube Pin No. Typical Reading Notes
V1, 6U8A 1 < 50 kΩ Varies due to filter capacitors in circuit
2 10 kΩ to 100 kΩ Varies with setting of volume control
3 ~ 196 kΩ Varies due to filter capacitor in circuit
4 ~ 4.5 kΩ Heater
5 ~ 4.5 kΩ Heater
6 < 250 kΩ Varies due to filter capacitors in circuit
7 835 Ω
8 15.5 kΩ to 18 kΩ Varies with setting of R/L Balance Control (R20)
9 < 250 kΩ Varies due to filter capacitor in circuit
V2, 7027A 1 < 35 kΩ Varies due to filter capacitor in circuit
2 ~ 4.5 kΩ Heater
3 < 35 kΩ Varies due to filter capacitor in circuit
4 < 35 kΩ Varies due to filter capacitor in circuit
5 110 kΩ
6 110 kΩ
7 ~ 4.5 kΩ Heater
8 0 Ω
V3, 7027A 1 < 35 kΩ Varies due to filter capacitor in circuit
2 ~ 4.5 kΩ Heater
3 < 35 kΩ Varies due to filter capacitor in circuit
4 < 35 kΩ Varies due to filter capacitor in circuit
5 110 kΩ
6 110 kΩ
7 ~ 4.5 kΩ Heater
8 0 Ω