5
OUTPUT LEVEL
The 19 LED bar graph displays the output level of the MA-2.2B in dBu and has a fast
attack response similar to a peak program meter.
POWER
On the far right of the front panel (where it should be) is the mains power switch. We
recommend that your MA-2.2B remains powered whilst in regular use to maintain it’s
excellent sonic performance. But if you need to turn it off, this switch will do it. The
audio outputs are automatically MUTED during power up and power down.
REAR PANEL SIGNAL GROUND
On the back panel you will find this switch and it selects HARD or SOFT internal signal
grounding. In the HARD position, the MA-2.2B Signal Ground (common) is connected
directly to the mains earth and MA 2.2 chassis. In the SOFT position, the Signal Ground is
lifted from the mains earth via a 10 ohm resistor.
Normally the Signal Ground switch should be set to HARD. If you experience problems
with hum or earth loops when connecting the MA 2.2 to other devices, try the SOFT
position.
Please Note
The mains earth to MA 2.2 chassis connection is unaffected by this switch. Also, the
Chassis Ground connection on the output XLR and TRS jack connectors is unaffected by
this switch. Also see the Connections section of this manual.
4] Options
Output Transformer
Internal mounting studs on MA-2.2B bottom panel behind the main channel circuit board
are provided for fitting output transformers and the standard option is the Lundahl
LL1517. Buzz Audio can supply the Lundahl transformers pre-fitted to the MA-2.2B or as a
kit for retro fitting however soldering is required to fit them. Other transformers can also
be supplied, for further information contact your dealer or Buzz Audio.
5] Tips
Ensure the MA 2.2 has adequate ventilation. The Class A circuitry does generate a
fair amount of heat and the box will get warm. Avoid racking next to high heat
generating devices.
Avoid racking the MA 2.2 next to possible induced noise sources such as power
amplifiers, power conditioners, vacuum tube equipment or anything with a big power
transformer and equipment that uses large switching power supplies like computers.
Remember the standard output is unbalanced, if you seem to be getting no signal it
may be that the MA 2.2 output is being shorted by a reversed phase (pin 3 HOT)
unbalanced input.