Echolette MK I, User Manual, Page: 31 / 40

8. Using a voltmeter, measure the drop in voltage at the two resistors R53 and R54.
During measurement, turn the potentiometer anti-clockwise until the voltmeter displays
a value of 25 mV. This corresponds to a value of 25 mA. This current is flowing through
each of the two output stage tubes.
A difference of 2 … 3 mV is tolerable. If the difference is greater than 3 mV between the
two measured values, the output stage tubes are not well-tuned with each other and
must be replaced.
9. Leave the amp running for 15 minutes and then repeat the measurement. If no further
adjustments are needed, switch the device off, disconnect it from the mains and leave it
to cool down completely.
10. After the minimum wait time (ten minutes after disconnecting the voltage supply), place
the amp back in the housing and fit the cover on the reverse.
Maintenance
Echolette MK I
31