Buzzaudio MA-2.2B User manual

MA-2.2B TRUE CLASS A
MICROPHONE AMPLIFIER.
USERS MANUAL.
MA-2.2B USERS MANUAL 2019. CONTENTS COPYRIGHT BUZZ AUDIO LTD
PO BOX 171, BLENHEIM 7240, NEW ZEALAND. TELEPHONE [phone].
http://www.buzzaudio.com email [e-mail]

Welcome…
Thank you for choosing the Buzz Audio MA-2.2B True Class A Microphone Amplifier!
In this manual you will find important information regarding the use of your MA-2.2B and
we suggest that you do read it before using the unit.
If after unpacking the MA-2.2B you find any damage you should contact your dealer or
supplier immediately for advice on what to do.
We also suggest you retain the original packaging at least during the warranty period in
case you need to return the unit for service, however we are confident this will not be
necessary!!
 Warm Up.
The Buzz Audio MA-2.2B utilises discrete Class A amplifiers which take about 30 mins to
warm up. We suggest you keep the MA-2.2B switched on whilst in regular use to ensure
continuous sonic performance.
Contents…
1] The Mains Input - page 2
2] Rear Panel Connections - page 2
3] Controls and Indicators - page 4
4] Options – page 5
5] Tips – page 5
6] Service – page 6
7] Specifications – page 6
9] Warranty Information – page 7

2
1] The Mains Input
As a safety precaution your MA-2.2B may have shipped without a mains fuse fitted.
Before use, you must select the correct mains voltage for your local supply on the rear
panel and fit the correct mains fuse type into the fuse draw for that voltage.
 Setting the Voltage Selector
You will need a flat blade screwdriver.
If your mains voltage is 110V to 120V set the rear panel voltage selector to 120V.
If your mains voltage is 220V to 240V set the rear panel voltage selector to 240V.
POWERING UP THE MA 2.2 WITH THE WRONG VOLTAGE SETTING MAY CAUSE SEVERE
INTERNAL DAMAGE !!
 Selecting the Correct Fuse
In the supplied accessories bag you will find;
2x 0.5 Amp slow blow fuses, use for 220V to 240V.
2x 1.0 Amp slow blow fuses, use for 110V to 120V.
Slide out the fuse draw above the IEC power inlet and insert the appropriate fuse into
the carrier clip. Note there is also a position in the carrier for a spare fuse (the square
tube bit) and we suggest you store the second supplied appropriate fuse here.
 Please Note
Fitting the wrong fuse may result in the fuse blowing on power up or inadequate
protection. Fitting fast blow type fuses may also result in the fuse blowing on power up.
The MA-2.2B may have been shipped with the mains set up to match your country but it
pays to check.
2] Rear Panel Connections
 MIC IN
The MA-2.2B is designed as a balanced input microphone amplifier. The connection of
unbalanced sources is not recommended. The XLR female style input connector is wired
as follows;
Pin 1 = Signal Ground (common)
Pin 2 = Signal Hot (+)
Pin 3 = Signal Cold (-)

3
 LINE OUT
The MA-2.2B has two output connectors. In standard configuration the output is
unbalanced to avoid the extra amplifier stage required and maintain the shortest
possible internal signal path.
The XLR male output connector is wired as follows;
Pin 1 = Chassis Ground
Pin 2 = Signal Hot (+)
Pin 3 = Signal Ground (common)
If you treat the MA-2.2B output as balanced and use normal XLR balanced leads there
should be no problems connecting to other gear.
If the optional output transformer is fitted (see the section on Options) the XLR is wired
as follows;
Pin 1 = Chassis Ground
Pin 2 = Signal Hot (+)
Pin 3 = Signal Cold (-)
 LINE OUT DIRECT
This TRS ¼” jack socket carries the unbalanced output signal even if the optional output
transformers are fitted, and it is wired as follows;
Tip = Signal Hot (+)
Ring = Signal Ground (common)
Sleeve = Chassis Ground
As for the XLR output, if you treat the direct output as balanced and use normal TRS
balanced leads there should be no problems connecting to other gear.
 Please Note
The Chassis Ground connection is intended for connecting cable SHIELDS. When
connecting the MA-2.2B output to other devices, it is not always necessary to connect
the shield at both ends of the cable. This may help prevent earth loops occurring. The
mic input Signal Ground however is always connected at both ends to ensure correct
shielding of the cable and mic body.
The Signal Ground source can be selected HARD or SOFT, see the Controls and Indicators
section.

4
3] Controls and Indicators
 GAIN dB
Adjusts the gain/volume of the MA-2.2B from +14dB in 2dB steps up to +48dB then 3dB
steps up to +66dB.
 MUTE
This push button switch mutes the MA-2.2B audio output when illuminated. Not much
more can be said about it!
 -20dB
This push button switch introduces a 20dB pad or attenuator right at the microphone
input which is useful when recording loud sources that might otherwise cause clipping at
the output. Activated the pad does not affect the loading of the connected microphone
as it is always p[art of the input circuit.
 Ø REV
When illuminated the polarity of the output signal is reversed 180 degrees relative to the
input signal and this is useful in multi-microphone set up to avoid phase cancellation.
 LO-Z
When illuminated the input impedance of the mic input is changed from 3k ohms to 1k2
ohms. Which one to use? This is purely a subjective thing. Some microphones such as
dynamic and older tube types may sound better in the LO Z position.
 +48V
Controls the phantom power required for condenser microphones and active DI boxes.
When illuminated, 48V is applied to pin 2 and 3 of the mic input XLR connector via 6k8
ohm resistors. Note to avoid disasters, you need to hold the switch down for a few
seconds before it will change state.
NOTE - TO AVOID POSSIBLE DAMAGE TO THE INTERNAL CIRCUITS, WE SUGGEST
TURNING THE GAIN DOWN TO MINIMUM WHEN SWITCHING THE PHANTOM POWER ON
OR OFF.
 Automatic Muting
When changing the state of the push button functions above, the output of the MA-2.2B
is momentarily muted to avoid clicks and bangs that can occur.

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.

6
 Avoid connecting/disconnecting microphones with the GAIN on a high setting and/or
with the 48V phantom switched on. Switch the PAD on and MUTE the output. This
will avoid huge transients entering the amplifier front end.
 Clean the MA-2.2B with a damp cloth and a little detergent. Do not use solvents or
isopropyl alcohol, it may damage the finish and possibly remove the front panel
screen printing.
6] Service
Should you experience any technical problem with your MA 2.2, contact your dealer or
Buzz Audio for recommendations on what to do. The modular nature of the MA 2.2
construction means most electronic faults can be easily repaired by swapping circuit
boards.
For on line support visit our web site; http://www.buzzaudio.com
Buzz Audio Ltd
8 Opawa Street, Blenheim 7201 Marlborough, New Zealand.
Phone [phone]
Email; [e-mail]
7] Specifications
Min Gain; +14dB (-6dB with pad engaged)
Max Gain; +66dB
Max out level; +24dBu (0dBu ref = 0.775mV)
Harmonic Distortion (direct output);
100Hz 0.005%, 1kHz 0.005%, 10kHz 0.008%.
Common Mode Noise Rejection;
100Hz 80dB, 1kHz 80dB, 10kHz 70dB.
Equivalent Input Noise;
-133.5dB (A Weighted with 150 ohm source impedance).
Bandwidth;
2Hz to 250kHz @ 20dB gain.
20Hz to 250kHz @ 64dB gain.
(with LL1517 output transformer); 10Hz to 200Khz
Slew Rate (direct output); 140V/uS
Input Impedance;
3k ohms/1k2 ohm switchable.
Power Requirements; 230/115 Volts selectable on rear panel.
Package; 1U rack mount. 481W x 44.5H x 300D (mm).
Weight; 5kg

7
9] Warranty Information
 Disclaimer
Buzz Audio is not liable for any damage to microphones, amplifiers, consoles, speakers or
any other equipment and/or electric shock to humans that is caused by negligence or
improper installation and/or use of the MA-2.2B True Class A Microphone Amplifier.
 Standard Product Warranty
Buzz Audio guarantees the MA-2.2B True Class A Microphone Amplifier to be free of
defective materials and/or workmanship for a period of 1 year (12 months) from the date
of sale, and will replace defective parts and repair malfunctioning products under this
warranty when the defect occurs under normal installation and use – provided the unit is
returned to our factory (or duly authorised service centre) via prepaid transportation
with a copy of the proof of purchase, ie, sales receipt. This warranty provides that
examination of the returned product must indicate, in our judgement, a manufacturing
defect. This warranty does not extend to any product that has been subjected to
misuse, neglect, accident, improper installation, or where the date code has been
removed or defaced. The standard warranty is NOT transferable.
 Product Warranty Extension
The above Warranty may be extended to a period of 2 years (24 months) from date of
sale provided the Warranty Registration form on our website is completed within 28
days (4 weeks) from date of purchase. The Extended Warranty is transferable.
http://www.buzzaudio.com/register.php
MA-2.2B USERS MANUAL 2019. CONTENTS COPYRIGHT BUZZ AUDIO LTD
PO BOX 171, BLENHEIM 7240, NEW ZEALAND. TELEPHONE [phone].
http://www.buzzaudio.com email [e-mail]