Adjustment Procedures; Offset - SPHINX Myth 1 Service Manual

SPHINX Myth 1

7. ADJUSTMENT PROCEDURES

The Myth 1 only has one parameters for each
channel (so two in total) that might need
adjustment:
- Offset: to set the DC-offset voltage of the
output.
These adjustments might be necessary when the
amplifier has been used for a period of time (and
settings have changed due to ageing) or when parts
of the Myth 1 have been replaced.
Service Manual

Offset

The Offset adjustment procedure minimises the DC
offset value of the amplifier output.
•
Switch the amplifier ON and wait until it has
reached the proper working temperature.
•
Set the millivolt-meter to the DC-range.
•
Place the measurement clips of the meter over
the output.
•
The level should not exceed +1 or -1 mV DC.
If it does: adjust potmeter P2L (Left) or P2R
(Right) until the level is within this range.
•
Repeat this procedure after 20 minutes to
finalise the adjustment.
•
Switch the oscillator on and set it to 1 kHz and a
level of 0 dBV (1 V).
•
Check the distortion with a THD analyser: it
should be conform to the specified value
(0.002% IHF-A @ 1 – 20 kHz).
If this is correct the procedure is finished.
•
You may now switch off the amplifier
10