Millennia M-2B User manual

1
M-2b
READ THIS FIRST!
Any changes or modifications not expressly approved by MILLENNIA MEDIA, INC. could
void your authority to operate this equipment under the CE or FCC rules.
1. Copyright: You acknowledge that no title to the intellectual property in the M-2b is trans-
ferred to you.
2. Inspection: Inspect packing boxes, M-2b, and cables for damage, unusual marks, or short-
ages. It is your responsibility to report damage, shortage, or misshipments in a timely manner.
Millennia Media and/or its dealers will not be responsible for claims arising from damage in
shipping, nor will claims for shortage or misshipments be honored, more than 10 days after
ship date.
3. Read this manual carefully and completely before attempting to use the M-2b. Improper
operation could result in damage to product. It is the user's responsibility to understand the safe
use and operation of this device.
4. The shipping box of the M-2b system will include (1) Owner's Manual, (2) M-2b, (3) a UL
approved power cord, (4) Owner's Registration Card. Fill out the Owner's Registration Card
and return to Millennia Media at your earliest ability.
The material contained in this manual consists of information that is property of Millennia
Media, Inc. and is intended solely for use by the purchasers of the equipment described in this
manual. Millennia Media, Inc. expressly prohibits the duplication of any portion of this manual
or the use thereof for any purpose other than the operation and/or maintenance of the equip-
ment described in this manual without the express written permission of Millennia Media, Inc..
Under copyright laws, this manual may not be duplicated in whole or in part without the writ-
ten consent of Millennia Media, Inc..
M-2b is a trademark of Millennia Media, Inc. All other trademarks are property of their re-
spective holders. Serial numbers are located on the rear left side of each unit. We suggest that
you record the serial numbers in the space provided below. Refer to it whenever you call an
authorized Millennia Media repair facility or the manufacturer. Make sure that you return your
completed warranty card immediately.
Features and specifications subject to change without notice.
© 1999 Millennia Media, Inc., All rights reserved
Serial Nos. ______________________________________________________________
Purchase Date ___________________________________________________________
Where Purchased _________________________________________________________

M-2b
2
SAFETY PRECAUTIONS
For your safety and the safety of others, be sure to read and understand all safety and opera-
tional instructions before attempting to use the M-2b. WARNING: The M-2b internal circuitry
carries lethal voltages. Carefully observe all warnings, precautions, and instructions on the M-
2b and as described in the instructions supplied with the unit.
1. WATER, MOISTURE, AND SPILLAGE
Do not attempt to use the M-2b in, near, or around water or in unusually moist environments,
such as near a sink or swimming pool. Prevent liquids or any other materials or objects from spill-
ing or falling into the M-2b unit.
2. HEAT AND VENTILATION
Be sure to allow adequate ventilation to M-2b and avoid using or installing unit in close proximity
to heat sources, such as heaters, stoves, radiators, power amplifiers, spotlights, or other heat-pro-
ducing appliances or equipment.
3. POWER SOURCES AND POWER CORD PROTECTION
The M-2b Power Supply should be connected to a power source only of the type described in the
operating instructions or as marked on the Power Supply. Route the power cord so that it is not
likely to be walked on or pinched by having objects placed on it. Pay particular attention to plugs,
receptacles, and the point where the AC power cord exits the M-2b.
4. GROUNDING
For your safety, it is extremely important that the grounding pin of the 3-wire power cable (included
with unit) be inserted into a grounding type 3-pin power outlet. If you are unable to insert the plug
into an existing outlet, contact an electrician to install a properly grounded 3-pin power outlet.
5. DAMAGE REQUIRING SERVICE
This unit should be repaired or serviced by qualified personnel whenever:
· The AC power cord has been damaged, or
· Objects have fallen or liquid has spilled into any M-2b unit, or
· The unit does not function properly or exhibits a marked change in performance, or
· The unit has been abused, dropped, or damaged, or
· The unit has been exposed to rain or moisture
6. SERVICING
Lethal voltages are found inside the M-2b chassis. The user should not attempt to repair or service
this unit. All servicing and/or repairs should be referred to Millennia Media.
If, after reading all instructions, precautions, and warnings, you have remaining questions, please
contact Millennia Media directly before attempting to use your M-2b. Retain this owner’s manual
as a record of your purchase to aid positive identification in the event of loss.

3
M-2b
QUICK START!
READ THIS!! The M-2b operates with lethal operating
voltages -- the voltage inside the M-2b can kill you. Never,
under any circumstances, remove the top cover. Refer to a
qualified electronics technician any and all servicing, tube
replacement, and other operations which require the top
cover to be removed.
Congratulations on your purchase of the Millennia Media M-2b vacuum tube microphone
preamplifier. The M-2b is the result of meticulous listening tests on numerous circuit, topology,
and packaging designs. Your M-2b is a finely tuned instrument intended for critical professional
applications — we feel it offers the world's most elegant vacuum tube mic preamplifica-tion.
With the emergence of 24+ bit digital audio, recording engineers are faced with a new require-
ment for undistorted dynamic range. The M-2b meets this challenge exceptionally well.
Before connecting power to the M-2b, assure that the rear panel voltage selection fuse block
switch is set correctly. In the USA, the M-2b is shipped with the voltage selection block set to
100-120 VAC. At this voltage setting, a pair of 1 amp 5 x 20 mm slow blow fuses have been
factory installed. If you change the voltage selection block to 200-240 VAC usage, be sure to
change both fuses to 500 milliamp (0.5 amp) slow blow types.
The M-2b enclosure measures 19" wide x 3.5" high x 13.75" deep and is designed for mounting
into a standard 2U, 19" equipment rack. If the M-2b is mounted into a road case or other rack
which is prone to strong vibration or shock, it is recommended that the rear of the M-2b be
supported or otherwise reinforced to withstand such conditions. The M-2b requires adequate
ventilation. To assure proper air circulation and operation, leave at least one rack screw space
open above the M-2b chassis.
The M-2b is designed on a common ground topology. For high quality operation, and for your
own safety and the safety of others, do not defeat the purpose of the earth grounding pin on the
A/C power cord!
NOTE:
The M-2b is based on pure Class-A all vacuum tube design. Such topology performs best after
reaching a stable, warmed-up condition. All M-2b factory adjustments have been performed
when unit is fully warmed-up; at least one-half hour after turning unit on. It is recommended
that to achieve optimal sonic performance with the M-2b, allow a warm-up period of at least
one-half hour.

M-2b
4
M-2b REAR PANEL
(1) CONVENTIONAL (+48V) INPUTS "In 1 (Left), In 2 (Right)"
Conventional 3-pin female XLR input jacks for all balanced microphones. Pin 1 is chassis
ground, pin 2 is positive phase audio signal, pin 3 is negative phase audio signal. Input imped-
ance is 3,800 ohms.
(2) DPA (B&K) HIGH VOLTAGE (+130V) INPUTS — optional
Conventional 4-pin female XLR input jacks for use only with B&K 4000-series high voltage
audio microphones. Pin 1 is chassis ground, pin 2 is unused, pin 3 is +130VDC, pin 4 is audio
signal. Input impedance is 9,000 ohms.
(3) OUTPUTS "Out 1 (Left), Out 2 (Right)"
Conventional 3-pin male XLR unbalanced outputs. Pin 1 is chassis ground, pin 2 is positive
phase audio signal, and pin 3 is audio ground. Output impedance is 120 ohms.
(4) EARTH/AUDIO GROUND JUMPER
A barrier terminal which ties earth ground to audio ground. If ground "hum" loops are expe-
rienced when using the M-2b, removing this jumper may help. Removing this jumper will not
compromise chassis/earth ground integrity.
(5) AC VOLTAGE MAINS SELECTION "100-120" or "200-240"
A power entry module with a removable fuse holder block. This fuse holder block is selectable
for 100 to 120 Volt or 200 to 240 Volt worldwide mains powering. The fuse block contains
two fuses — one fuse is in series with the hot power line while the other fuse is in series with
the neutral power line. Both fuses must be installed. To change the mains voltage selection,
remove IEC power connector and assure that the M-2b is not connected to mains power. With a
non-conductive tool, gently pry the fuse block away from the power entry module. Remove the
two fuses and replace both with type as shown below. Slide out the internal PC Board assy, turn
it over, and reinsert the PCB assy so that the desired AC mains voltage appears in the viewing
window. Double check that the fuses installed correspond to the AC mains voltage range which
appears in the viewing window. Gently push the fuse block back until flush and snug.
FUSES:
For 100-120 VAC mains, use 5x20mm, 1A, slow blow, 250V, Littelfuse 218 or equivalent.
For 200-240 VAC mains, use 5x20mm, 500mA, slow blow, 250V, Littelfuse 218 or equivalent.
(6) POWER ENTRY "IEC Power Receptacle"
An IEC-type AC line-power receptacle for use with removable cords. Use only the power cord
provided with the M-2b unit or equivalent U/L approved type SV, SVT, SJ, or SJT AC power
supply cord. Do not defeat the third pin earth ground! If ground lifting is desired, remove the
Earth/Audio Ground Jumper strap (3).

5
M-2b
This device complies with Part 15 of the FCC rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.
CHANNEL ONECHANNEL TWO
OUTOUT
GROUND LIFT
48V IN
48V IN 130V IN
130V IN
Millennia Music & Media Systems Placerville, California, USA 95667 Designed & Handcrafted in USA
Lethal voltages inside!
Do not remove top cover
CAUTION: To reduce the risk of fire, replace only with the same type fuse. To reduce the risk of electric shock, do not remove top cover. Refer to qualified technician all maintenance, tube replacement, servicing, and any other work requiring removal of top cover.
ATTENTION/AVIS: Risque de choc electrique ne pas ouvrir.
PUSHPUSH PUSHPUSH
115
M-2b Rear Panel

M-2b
6
M-2b FRONT PANEL
(1) GAIN TRIM "GAIN TRIM 0 - 12 dB"
Conductive plastic rotary potentiometer offering a gain trim range of 12 dB. Working in con-
sort with range switches (2) and (3) below, the Gain Trim allows fine adjustment of microphone
gain. When fully CCW, there is no additional gain added (0 dB). When fully CW, an additional
gain of approximately 12 dB is realized.
(2) MEDIUM RANGE SWITCH ("MEDIUM GAIN RANGE")
The first of two pushbutton switches used to select the gain range of the M-2b preamplifier. See
below (3) for complete description.
(3) HIGH RANGE SWITCH ("HIGH GAIN RANGE")
The second of two pushbutton switches (2) and (3) used to select the gain range of the M-2b
preamplifier. These two pushbutton switches define three preamplifier gain ranges, as follows:
a.) LOW RANGE: When both switches (2) and (3) are not depressed and corresponding LEDs
are not illuminated, microphone preamplifier is set to "Low Gain Range." Low Gain Range is
defined as approximately 14 dB to 26 dB, adjustable by the Gain Trim control (1) above.
b.) MEDIUM RANGE: When switch (2) is depressed and switch (3) is not depressed, micro-
phone preamplifier is set to "Medium Gain Range." Medium Gain Range is defined as approxi-
mately 26 dB to 38 dB, adjustable by the Gain Trim control (1) above.
c.) HIGH RANGE: When switches (2) and (3) are both depressed and corresponding LEDs are
both illuminated, microphone preamplifier is set to "High Gain Range." High Gain Range is
defined as approximately 38 dB to 50 dB, adjustable by the Gain Trim control (1) above.
(4) HIGH VOLTAGE DPA (B&K) MIC INPUT SELECT "+130V"
Routes the optional DPA (Bruel & Kjaer) microphone input to the microphone preamplifier.
High voltage supply is not effected by this switch (e.g., the +130 VDC supply is always present
on pin 3 of the optional four pin mic input XLR irrespective of where this switch is set).
(5) PHANTOM POWER SELECT "+48V"
Routes +48 VDC "phantom" voltage to the 3-pin XLR microphone inputs for use with all con-
ventional phantom powered microphones. If "DC Option" has been installed, and this switch is
not depressed, the conventional front end becomes entirely DC coupled — an ideal match for
ribbon mics, moving coil mics, and so forth.
(6) POLARITY REVERSE "PHASE"
Pushbutton switch which, when depressed and corresponding LED is illuminated, flips the mi-
crophone polarity (output becomes 180 degrees out of phase with respect to the input). When
switch is not depressed, microphone signal remains in phase from input to output.
(7) POWER SWITCH "POWER"
Rocker switch for switching AC line power on and off.

7
M-2b
M-2b Front Panel
POWER
M-2b
Millennia
Transformerless Vacuum Tube
Stereo Microphone Preamplifier
Music & Media Systems
GAIN TRIM
(dB)
GAIN TRIM
(dB)
012
MEDIUM
GAIN
RANGE
MEDIUM
GAIN
RANGE
LOW GAIN RANGE
BOTH OFF
LOW GAIN RANGE
BOTH OFF
HIGH
GAIN
RANGE
HIGH
GAIN
RANGE
+130V +130V+48V +48VPHASE PHASE
+ +
CHANNEL 2CHANNEL 1

M-2b
8
A WORD ABOUT DPA (Brüel & Kjær) MICROPHONES
At present, Danish Pro Audio (formerly Brüel & Kjær Pro Audio Division) manufactures two families
of 4000-series professional recording microphones. One family is +48 VDC phantom powered, the
other is +130 VDC direct powered. A primary difference between families (4003/4 vs. 4006/7) is that
the high voltage microphones are transformer-less whereas the phantom powered varieties are trans-
former coupled. Millennia Media has used both varieties extensively with symphony orchestra, choir,
jazz ensemble, pop recording, and so forth. We have found the transformerless high voltage omni ver-
sion to perform substantially better than its transformer-coupled omni counterpart. The transformerless
version (4003) sounds generally "clearer" and more true to the source; especially during frequency and
amplitude extensions. And this is saying a lot considering that DPA's transformer-coupled microphones
sound extremely pure.
The following is a brief summary of DPA high-voltage microphone products and specications. Most of
this material is taken directly from DPA's documentation and is thought to be accurate, however, Millennia
Media assumes no responsibility for errors or subsequent changes in the following specications. Those
desiring up-to-date information concerning DPA microphones should contact DPA directly.
Model 4003 4004 4012
Pattern OMNI OMNI CARDIOID
Self-Noise 15 dB (a) 24 dB (a) 19 dB (a)
SPL (max) 154 dB SPL 168 dB SPL 168 dB SPL
Freq Response8 Hz - 30 kHz 8 Hz - 45 kHz 35 Hz - 25 kHz
Impedance < 30 ohms < 30 ohms < 30 ohms
Sensitivity 50mV / Pa 10 mV / Pa 9 mV / Pa
A number of options are available for the 4003 microphone. One grid, the 0777, provides superior omni-
directional response throughout the high frequencies. Another grid, the 0297, provides a high frequency
presence boost. The standard grid provides the most accurate response on-axis. A development called
the APE (acoustic pressure equalizer) tailors the 4003 to respond like vintage M-50 or newer TLM-50
microphones. The various APE attachments boost mid to high frequencies arriving on axis without ex-
hibiting proximity effect at lower frequencies. When used with various grids, numerous polar patterns
and response curves can be achieved.
DPA offers a service of factory-matching new pairs of high voltage (+130 VDC) microphones for tight
stereo tracking of sensitivity and frequency response curves. Millennia Media highly recommends this
service and can assist customers in obtaining these microphones. A high voltage microphone preamplier
upgrade is available for your M-2b at any time. Please call the factory for details.

9
M-2b
M-2b TYPICAL MEASURED SPECIFICATIONS
THD + Noise, 22 Hz - 22 kHz < .01% @ +0 dBu
Frequency Response (-3 dB points) 4 Hz to 200 kHz
Maximum Input Level (+14 dB gain) +20 dBu
Maximum Output Level > +35 dBu
Input Impedance 3,800 ohms (conventional mic input)
9,000 ohms (high voltage mic input)
Output Impedance 120 ohms
Recommended Load (important) > 2,000 ohms
Noise (22 Hz - 22 kHz @ 50 dB gain) -116 dBu EIN, 150 ohm source
Common Mode Rejection Ratio > 80 dB, 100mV @ 1 kHz
XLR Polarity Pin 2 positive polarity, Pin 1 = ground
Gain Ranging (approximate) Low Range: 14 dB - 26 dB
Medium Range: 26 dB - 38 dB
High Range: 38 dB - 50 dB
Phase Reverse Switching? Yes
Phantom Switching? Yes
DPA (B&K) Switching? Yes, optional
Gain Range Switching? Yes, 3 ranges
Gain Adjustment Conductive Plastic Rotary Potentiometer
ELECTRO-MECHANICAL SPECIFICATIONS
Power Consumption 50 Watts, nominal
Power Requirements 100VAC to 240VAC, 50/60Hz, selectable
Fuses (2 required) 2 ea 1A with 100-120VAC mains (5x20mm,
slow-blow, 250V)
2 ea 500mA with 200-240V mains (5x20mm,
slow-blow, 250V)
Internal DC Power +350V, +130V, +48V, -24V, +12V
Dimensions 19" W x 13.75" D x 3.5" H
Net Weight 24 pounds
Millennia Media reserves the right to change specifications, delivery, and pricing without notice.

M-2b
10
WARRANTY
Millennia Media will repair this product, free of charge, in the USA, in the event of defect of
materials or workmanship for one (1) year following date of purchase. This warranty is ex-
tended only to the original purchaser. This limited warranty covers failures due only to defects
in materials and workmanship which occur during normal, intended use and does not cover
damage which occurs in shipment or failures which are caused by products not supplied by Mil-
lennia Media. This limited warranty does not cover failures which arise from accident, misuse,
abuse, neglect, mishandling, misapplication, faulty installation, improper adjustment, alteration
or modification of product, incompatibilities, line-power surges, acts of God, or service per-
formed by anyone other than Millennia Media or its authorized agent. Vacuum tube failures are
not covered under warranty.
LIMITS AND EXCLUSIONS
There are no express warranties except as listed above. Millennia Media shall not be liable for
special, subsequent, incidental, consequential, or punitive damages, including, but not limited
to: damage to recordings, microphones, mixing consoles, or any associated equipment, down-
time costs, loss of goodwill, or claims of any party dealing with purchaser for such damages re-
sulting from the use of this product. All warranties, express and implied, including the warran-
ties of merchantability and fitness for a particular purpose are limited to the applicable warranty
period set forth above.
Some states do not allow the exclusion or limitation of incidental or consequential damages, or
length of time an implied warranty remains in effect. As such, the above exclusions may not ap-
ply. This warranty gives you specific legal rights and you may also have other rights which can
vary from state to state.

11
M-2b
MILLENNIA MEDIA, INC.
4200-B Day Spring Court
Placerville, CA 95667-9500
Web: http://www.mil-media.com
Email: [email protected]
T 530-647-0750
F 530-647-9921
The M-2b is hand-crafted in USA
Manual printed in USA
M2B-A-100-899