Grace M201 User Manual 2

m201

microphone preamplifier

optional A/D converter module

manual Rev D

owner’s manual

all contents ©2007 Grace Design/ Lunatec LLC

Welcome

Thank you for purchasing the Grace Design m201 microphone preamplifier. With the
combination of unmatched sonic performance, powerful features, and solid reliability,
the m201 is a powerful recording tool designed to help you make the best recordings
of your career.

We have designed the m201 to be as easy and intuitive to use as possible. However,
we strongly recommend that you read this product manual thoroughly to familiarize
yourself with the unique features and capabilities of the m201.

Also, please do not hesitate to contact us directly if you have any questions, comments,
or concerns with your new m201 microphone preamplifier. Thanks for reading and
happy recording!!

-The Grace Design Team

Contents

Welcome 2

Important Safety Information 3

Front Panel Controls 4

Rear Panel Connections 5

Audio Connections 6

Power Connections 6

Preamplifier Operation 7

Ribbon Mic Mode 8

M-S recording with the m201 9

The Optional A/D Converter Features 9

Operating The A/D Converter Module 10

A/D Converter Sensitivity 11

Maintenance 14

Cleaning 15

Specifications 17

Signal Flow Diagram 18

Warranty Information 19

Manual Revisions 20

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owner’s manual

Important Safety Information

GENERAL

•Indoor use only

•Ordinary Protection: This equipment should not be exposed to dripping or splasing.

•Avoid placing objects filled with liquids, such as vases or glasses, on this equipment.

•Class I Equipment (grounded type)

•Electrical rating: 100-120/220/230-240V~ 50-60Hz 30W

•Mains supply voltage fluctuations are not to exceed ±10% of the nominal supply voltage.

•Pollution Degree 2

•Installation (Overvoltage) Category II for transient overvoltages.

•Maximum Relative Humidity: <80%

•Operation temperature range: 10 °C to 40 °C

•Storage and transportation temperature range –40 °C to 70 °C

•Maximum altitude: 3000m (9843 ft)

•Equipment suitable for continuous operation

•Weight: preamplifier - 7.5kg (16.5lbs)

SAFETY MARKING SYMBOLS

CAUTION: READ ACCOMPANYING DOCUMENTS

This symbol, located on the equipment and in this manual, refers to impor­tant instructions. Read this manual thoroughly before operating this equip­ment.

WARNING: ELECTRICAL SHOCK HAZARD

This symbol, located on the equipment and in this manual, indicates the
potential for electrical shock hazard.

SERVICE INFORMATION

The Grace Design m201 contains no user serviceable components. Contact Grace Design
for repair and upgrade information. In the event that your Grace Design m201 needs to be
returned to the factory, contact us for a return authorization number.

grace design m201

owner’s manual

3

M+S WIDTH

100m

70m
30s

30m

70s

50m
50s

GRACE DESIGN USA

m201microphone preamplifier

HI-Z

1

48V

HI-Z

130V

ribbon

(

+10dB

)

20

30

40

50

60

INPUT MODE

+48V - 20dB

HI-Z

2

48V

HI-Z

130V

ribbon

(

+10dB

)

20

30

40

50

60

INPUT MODE

+48V - 20dB

Front Panel Controls

A

D

E

A

switch

Each gain control has 24 positions and adjusts the volt-

age gain from 18dB to 64dB in 2dB steps. In ribbon

mode the gain range is 28dB to 74dB in 2dB steps.

B

bi-color LED peak indicator

The LED peak indicator, which monitors the output sig-

nal level, turns green at -14dB and switches to red at

+16dB (12dB before clipping). The threshold level for

peak indication is adjustable on each channel (see the

calibration section of this manual).

C

input mode switch

The input mode switch is used to select between the

various types of inputs available with the m201, includ-

ing standard 48V, ribbon mic mode, HI-Z, or the optional

130V DPA™ inputs. Refer to the m201 block diagram at

the end of this manual for signal routing details.

D

The phantom power switch (labeled +48V) connects

the +48V power supply to pins 2 and 3 on the XLR in-

put connector. This switch illuminates red. It should be

noted that the LED in this switch actually monitors the

phantom power voltage at the input. With no micro-

phone connected, the LED will continue to illuminate

for approximately 10 seconds after the phantom power

is turned off as the filter capacitors discharge. As well,

even if the phantom power is switched off, the LED will

illuminate if voltage is being fed from an external source.

(i.e. when using a direct split in a remote recording ap-

plication.) Also, the +48V switch is used to activate the

+130V DPA™ mic power if this option is installed.

E

polarity reversal switch

The polarity reverse switch reverses the absolute phase

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owner’s manual

C

B

GF

24 position gold contact gain

48V phantom power switch

H

of the music signal at the input of the preamplifier.

The switch illuminates green and provides power for

a sealed gold contact relay located on the preamplifier

circuit board. This eliminates signal wiring to the front

panel and switch contact performance problems. The

polarity reverse function is active for all input connec-

tors.

F

-20dB pad switch

The 20dB attenuator switch attenuates the input signal

20dB. The switch illuminates amber when engaged.

Like the phase reverse switch, this switch controls a

sealed gold contact relay on the preamplifier circuit

board. With the -20 switch engaged, the effective gain

range becomes -2dB to 44dB. The 20dB attenuator is

active for 48V Phantom, ribbon and (optional) DPA in-

puts. It does not affect the HI-Z inputs.

G

HI-Z input

This 1/4 inch TRS input is active when the input mode

switch is in the HI-Z position. Suitable for any high

impedance source such as: bass guitar, acoustic guitar,

electric guitar, keyboards, etc... This input is can be used

balanced with a TRS connector or unbalanced with a TS

connector.

H

M-S width control

This knob controls the ratio between the Mid and Side

signals in an M-S recording setup. Please see the ‘pre-

amplifier operation’ section of this manual for complete

information regarding this feature.

I

standby switch

Connects the mains voltage and turns on the m201

When depressed the pushbutton will illuminate green

and the preamplifier will be on. When released the pre-

amplifier will be in standby mode.

I

120Vac

PUSH

PUSH

PUSH

1

3

2

4

PUSH

1

3

2

4

PUSH

PUSH

WORD/LOOP CLOCK

S/PDIF

LINE IN

TOSLINK

AES3 OUT

OUT

IN

RIGHT

LEFT

M+S O UT

130V

MIC IN

1

2

MIC IN

OUTOUT

MIC IN

OUTO UT

GRACE DESIGN USA

m 012

microphone preamplifier

1

2

Pb

LEAD FREE

RoHS

COMPLIENT

Rear Panel Connections

E

D

A

XLR mic input connectors

Input connections are made via female XLR connectors

with pin 2 positive, pin 3 negative and pin 1 ground.

48V phantom power is supplied on pins 2 and 3.

B

XLR output connectors

Parallel XLR outputs are provided for sending line sig-

nals to two seperate recording devices or mixers. Out-

put connections are made via male XLR connectors

with pin 2 positive, pin 3 negative and pin 1 ground.

C

M-S XLR output connectors

XLR outputs are provided for sending M-S signals in-

dependently of the standard line outputs. Output con-

nections are made via male XLR connectors with pin 2

positive, pin 3 negative and pin 1

D

IEC AC power input

Accomodates the included 3 prong AC cable. Connect

to grounded outlet only.

ground.

C

B

A

E

130V DPA microphone inputs (op-

tional)

Accomodates 130V DPA© microphones via 4 pin XLR

connectors.

F

Optional A/D Converter module

Optional A/D converter module for the m201 includes

seperate balanced analog A/D line inputs, 2x AES3 out-

puts (single and dual wire), word clock/ loop sync in

and out, S/PDIF out and TOSLINK optical out.

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owner’s manual

Audio Connections

1

2

3

SHIELD

HOT

GND

(open)

Microphone input connections are made via female XLR connectors with pin 2 posi­tive, pin 3 negative and pin 1 ground. 48V phantom power is supplied on pins 2 and

3. Output connections are made via male XLR connectors with pin 2 positive, pin 3

negative and pin 1 ground. If the output is to be used unbalanced, pin 1 should be
connected to signal ground and pin 2 to signal hot. Due to the nature of the balanced
output stage, pin 3 should be left open for unbalanced operation. See

Note: This will provide a signal of positive absolute polarity when the preamplifier is being
used with a microphone which produces a positive voltage on pin 2 with positive air pres­sure on the front of the diaphragm. While a vast majority of microphones conform to this
standard a few do not. Use the phase reverse switch to compensate if necessary.

<figure 1> - Unbalanced output cable termination

To connect to the front panel HI-Z input, the input mode selector switch must be
positioned in the “HI-Z” location, which changes the preamplier input source from
the mic input connector to the front panel TRS jack. The input impedance of the in­strument input is 2M Ohm (balanced) and 1M Ohm (unbalanced), which is ideal for

inserting high impedance sources such as guitars with passive pickups as well as any
instrument with a high level output. Wiring of the HI-Z jack is Tip positive, Ring nega­tive, and Sleeve ground. Please note that the gain range of the preamplifier when us-

ing the instrument input is –2dB to +48dB in 2dB steps.

<figure 1> below.

Power Connections

A standard three prong AC power cable is included with the m201. For
safety, the power supply cord must be connected to a grounded outlet.

The Disconnect Device for the m201 is the Mains plug or the Appliance
Coupler on the power supply cord. The Disconnect Device must remain
accessible and operable

AC input voltage settings can be adjusted for 100V, 120V, 220V and 240V operation at
50-60Hz. If your line Voltage is 230VAC then use the 240V setting. From the rear of the
m201, open the trap door next to the IEC power inlet with a small screwdriver. Care-

fully pull the voltage select cam straight out and then insert with the desired voltage

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owner’s manual