advertisement
m 201
Microphone Preamplifier / ADC
Owner’s Manual Rev F
All contents ©2012 Grace Design
Welcome
Thank you for purchasing the Grace Design m201 microphone preamplifier. With the combination of unmatched sonic performance, useful 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
The Optional A/D Converter Features
Operating The A/D Converter Module
Adjusting A/D Converter Sensitivity 10
2
grace design
m
201 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
m
201 owner’s manual
3
Front Panel Controls
1
2
3
30
+
20
48V
40
60
50
20dB
1
48V ribbon
( +10dB )
HI-Z
130V
INPUT MODE
30
20
40
60
50
2
HI-Z +
48V
-
20dB
48V ribbon
(
+10dB
)
HI-Z
130V
INPUT MODE
70m
30s
100m
30m
70s
M+S WIDTH
HI-Z
4
5
6 7
1.
24 position gold contact gain switch
Each gain control has 24 positions and adjusts the voltage gain from 18dB to 64dB in 2dB steps. In ribbon mode the gain range is 28dB to 74dB in 2dB steps.
2.
bi-color LED peak indicator
The LED peak indicator, which monitors the output signal 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).
3.
input mode switch
The input mode switch is used to select between the various types of inputs available with the m201, including 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.
4.
48V phantom power switch
The phantom power switch (labeled +48V) connects the +48V power supply to pins 2 and 3 on the XLR input 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 microphone 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 application.)
Also, the +48V switch is used to activate the +130V
DPA™ mic power if this option is installed.
m 201 microphone preamplifier
GRACE DESIGN USA
8
9
5.
polarity reversal switch
The polarity reverse switch reverses the absolute phase 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 connectors.
6.
-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 inputs. It does not affect the
HI-Z inputs.
7.
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.
8.
M-S width control
This knob controls the ratio between the Mid and
Side signals in an M-S recording setup. Please see the ‘preamplifier operation’ section of this manual for complete information regarding this feature.
9.
standby / power switch
Connects the mains voltage and turns on the m201When depressed the pushbutton will illuminate green and the preamplifier will be on. When released the preamplifier will be in standby mode.
4
grace design
m
201 owner’s manual
Rear Panel Connections
m 2 01 microphone preamplifier
GRACE DESIGN USA
4
LEAD FREE
Pb
RoHS
COMPLIENT
OUT
6
S/PDIF
IN TOSLINK AES 2 AES 1
M+S OUT
PUSH PUSH
LINE IN
PUSH
2
6
PUSH
2
4
3 2
1
PUSH
1
MIC IN
130V
4
3 2
1
PUSH
1
RIGHT
3
LEFT OUT OUT MIC IN OUT
2
OUT MIC IN
1
1.
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.
2.
XLR output connectors
Parallel XLR outputs are provided for sending line signals to two seperate recording devices or mixers. Output connections are made via male XLR connectors with pin 2 positive, pin 3 negative and pin 1 ground.
3.
XLR outputs
are provided for sending M-S signals independently of the standard line outputs.
Output connections are made via male XLR connectors with pin 2 positive, pin 3 negative and pin 1 ground.
4.
IEC AC power input
Accomodates the included 3 prong AC cable.
Connect to grounded outlet only.
5.
130V DPA microphone inputs (optional)
Accomodates 130V DPA© microphones via 4 pin
XLR connectors.
6.
Optional A/D Converter module
Optional A/D converter module for the m201 includes seperate balanced analog A/D line inputs,
2x AES3 outputs (single and dual wire), word clock/ loop sync in and out, S/PDIF out and TOS-
LINK optical out.
grace design
m
201 owner’s manual
5
Audio Connections
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
<figure 1>
below. 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.
2
1
HOT
GND
SHIELD
3 (open)
<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 preamplifier 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 using the instrument input is –2dB to +48dB in 2dB steps.
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
CHECK LINE VOLTAGE SETTINGS
Your m201 has been set from the factory to operate at the voltage required for your part of the world. However, it’s important to double-check this in order to ensure no damage will come to the unit if power is applied while the setting is incorrect.
AC input voltage settings can be adjusted for 100V, 120V, 220V, 230V and 240V operation at 50-
6
grace design
m
201 owner’s manual
60Hz. From the rear of the m201, open the trap door next to the IEC power inlet with a small screwdriver. Carefully pull the voltage select cam straight out and then insert with the desired voltage showing. Do not try to rotate the cam while it is in the power input module. Replace the fuses with the proper value selected from
<figure 2>
below. Be sure to use a time delay fuse with a 250V rating.
CAM SETTING
100V~
120V~
230V~
230V~
240V~
<figure 2 - fuse value table>
LINE VOLTAGE
100V~
120V~
220V~
230V~
240V~
FUSE VALUE
250V~ T 500mA L
250V~ T 500mA L
250V~ T 315mA L
250V~ T 315mA L
250V~T 315mA L
Preamplifier Operation
TURNING THE POWER ON
The power switch is located on the m201 front panel. Pushing the power switch in turns the mains power on (switch illuminates green). Pushing the power switch again turns the mains power off.
USING THE INPUT MODE SELECTOR SWITCH
The input mode switch to the right of the gain control provides a convenient way for the user to select between the various types of inputs the m201 can accommodate. The following is an overview of the four settings:
48V
This setting should be selected for all general recording applications with most microphone types. In this position, the main XLR mic inputs are feeding the preamplifier and the dual XLR outputs are active. Proceed with the ‘setting the gain’ discussion below.
HI-Z
This setting is used to select the front panel mounted 1/4” instrument DI inputs. These inputs can accommodate a wide variety of high impedance input sources, including bass guitar, keyboards, electric guitars etc... In this mode, the rear panel XLR inputs are not active, while the dual balanced
XLR outputs carry the amplified signal from the DI inputs. There is no 48V phantom available on this input. The phase reverse switch is active, and the gain range of this input is -2dB to +44dB (20dB less than the 48V input), so therefor the -20dB pad is not available. This connector is balanced with the
Tip positive, Ring negative and Sleeve ground.
ribbon
This setting puts the m201 into ‘ribbon mic mode’, which is described in detail below. Use this input for ribbon microphones or any application where an additional 10dB of gain may be required. In this position, the main XLR mic inputs are feeding the preamplifier and the dual XLR outputs are active.
130V
This setting activates the optional 130V input module for DPA microphones. If the 130V input grace design
m
201 owner’s manual
7
option is present, this selection will deactivate the standard XLR inputs and enable the dedicated 4 pin 130V XLR inputs. In this mode, the 48V pushbutton switch will turn on the 130V power supply.
Phase reverse and -20dB pad are available in this mode. The dual balanced XLR outputs carry the output signal.
SETTING THE GAIN
First, turn the gain control fully counter-clockwise and check that the 48V phantom power is off.
Connect a microphone and then turn on the phantom power if required. When sending a signal to a recorder, converter or interface that has fixed input levels, simply increase the gain until the optimum recording level is reached. If the peak indicator flashes red excessively with the gain control in the fully counterclockwise position, engage the -20dB attenuator.
When sending a signal to a recorder with an input attenuator (i.e. the record level control on a DAT or CDR recorder) use the following procedure: With the sound source present, turn the gain control clockwise until the peak LED begins flashing red, then reduce the gain until the red stops flashing. Since red indicates a peak level which is 12dB before preamplifier clipping (6dB in unbalanced mode), it is OK for it to come on periodically during recording. If peak indicator flashes red excessively with the gain control in the fully counterclockwise position, engage the -20dB attenuator. Now adjust the recorder input control for the optimum recording level.
RIBBON MIC MODE
Selecting the ribbon mic position on the input mode switch optimizes the channel for ribbon microphones by boosting the gain by 10dB while disabling 48V phantom power and optimizing the mic input impedance. Before activating ribbon mic mode, make sure the channel’s gain is fully down
(counter-clockwise) and 48V phantom power is off. Now simply select ‘ribbon’ input mode and turn the gain control upwards until the proper recording level is achieved.
If you press the 48V phantom switch while the ribbon switch is engaged, the mic power will not turn on. However, if the 48V phamtom switch remains depressed and the input mode switch becomes inadvertently changed to ‘48V’, 48V phantom will consequently be activated, which can potentially harm a ribbon your microphone if it is still connected to the input. If the 48V phantom power switch is turned of and then the ribbon mode is selected, the preamplifier will wait until the phantom power voltage has completely discharged and then the ribbon mode will activate automatically.
An additional benefit of the ribbon mic mode is that the input DC blocking capacitors are relay bypassed to further simplify the m201’s signal path. Incidentally, the ribbon mode works very well with many lower output dynamic microphones as well as ribbon types.
M-S RECORDING
In M-S mode the m201 accepts the Mid signal in channel 1 and the Side signal in channel 2. The LEFT channel output connector provides the “sum” of the inputs and the RIGHT channel output connector provides the “difference” of the inputs. In M-S mode, the M-S width control adjust the ratio of Mid signal to Side signal in the dedicated M-S outputs. The LEFT and RIGHT M-S outputs are always active which allows the user to record the discreet Mid and Side signals from the preamplifier Channel
8
grace design
m
201 owner’s manual
1 and 2 outputs while also recording (or monitoring) the stereo composite from the M-S LEFT and
RIGHT outputs.
Note
: For more information on M-S recording we would highly recommend the AES paper written by Wes Dooley and Don Streicher called “M-S Stereo: A Powerful Technique for Working in Stereo”. This paper (No. 1792) is available from the Audio Engineering Society web page (www.aes.org).
The Optional A/D Converter Features
1 2 3
FS SELECT CLOCK SOURCE ADC MODE
10
9
44 48 88 96 176 192 INT WORD LOOP PRO 2WIRE CONS
OFF s LOCK
OVER
1
2
-60 -50 -40 -32 -28 -24 -20 -18 -16 -14 -12 -10 -8 -6 -5 -4 -3 -2 -1 0
14 16 18 20
HEADROOM
(dB)
<
-0.4
CAL
-0.3 -0.2 -0.1
0 0.1 0.2 0.3 0.4
LEVEL
>
OVER
CH1-2 MS LINE A B
4
ADC SOURCE
8 7
INPUT SENS
6
PEAK RESET / MODE
(hold)
5
1. FS SELECT this switch is used to toggle through the available ADC sampling rates
2. CLOCK SOURCE this switch is used to select the ADC clock source
3. ADC MODE this switch is used to select single or dual wire AES, and switch between either professional or consumer fomat
4. OVER lights illuminate when the ADC has been overloaded, and remain lit until the PEAK RESET swich is pushed
5. PEAK RESET / MODE This switch is used to clear peaks on the 20 segment led meter and to select how the meters display peak information.
6. INPUT SENSITIVITY CALIBRATION SCALE
7. INPUT SENS selects between the two programmable ADC input sensitivity settings.
8. ADC SOURCE selects the input source which feeds the ADC module
9. ADC headroom indicator
10. 20 segment LED level meter
Operating The A/D Converter Module
If you have purchased the optional A/D converter module for your m201, the following section will help you become familiar with its features and its operation. The m201 A/D card is available installed on new m201’s from the factory, or as an upgrade to your existing m201. If you need more information about upgrading your m201 with the A/D module, please feel free to call us at 303.443.7454.
INPUT SOURCE SELECT
The m201 A/D can receive signals from 3 different inputs: channels 1&2 from the mic preamplifier section, the M-S matrix outputs, or the external balanced line inputs (located on the back panel of the A/D module). The A/D source select switch (lower left) is used to toggle between the three input source options, which are illuminated green directly above in the bezel. grace design
m
201 owner’s manual
9
Simply push the button to select the input source you require.
FS SELECT
The m201 A/D converter can operate at sampling rates of 44.1, 48,88.2, 96, 176.4, and
192kHz. Whether operating on the internal crystal or an external clock source, you must select the appropriate sampling rate at which you wish to record. The top left switch above the A/D bezel labeled FS SELECT is used to toggle between all the available sampling rates. Simply push the button to select the sampling rate you require. The selected rate will be illuminated green below. Selecting
“OFF” puts the A/D converter circuitry in low power standby mode with all oscillators off.
CLOCK SOURCE
The m201 A/D can be run from the internal crystal, an external word clock source, or from Avid™ loopsync. The top middle switch, labeled CLOCK SOURCE, is used to select between these options. The selected clock source will be illuminated green below the switch.
A/D MODE
The m201 A/D is capable of transmitting AES/EBU digital audio in single or dual wire modes, and in either professional or consumer format. The upper left switch selects between these various formats. The selected format will be illuminated green below the switch.
PEAK RESET / MODE
High resolution 20 segment metering is included with the m201 A/D option.
When A/D input signals hit or exceed absolute zero (0dBfs), the over indicator lights (‘over’ placed above and below ‘0’ on the meter) will illuminate red and remain lit until the peak reset switch is pushed.
Peak signal levels are indicated by the highest level LED remaining lit. The peak indicators can programmed to remain lit indefinitely until the reset switch is pressed (infinite); stay lit for 4 seconds
(delay); or not stay lit at all (off). These three modes are selected by simply pressing and holding the
PEAK RESET / MODE switch for approximately 3 seconds, which toggles through the three available modes.
Adjusting A/D Converter Sensitivity
The m201 A/D converter features two independent A/D sensitivity configurations. The front panel interface allows the user to easily switch between these two calibrated settings. Each of the two input sensitivity ranges (A) and (B) can be configured for one of four standard A/D sensitivities. The following sections detail the operation and calibration of this feature.
SELECTING THE A/D SENSITIVITY
From the m201 front panel interface, pressing and releasing the
INPUT SENS push button toggles the selected A/D input sensitivity. The currently selected range (A) or (B) is illuminated.
CALIBRATING THE A/D SENSITIVITY
The m201 ships with the following two default sensitivity calibrations: (A)
+22dBu = 0dBFS
(18dB Headroom) (B)
+18dBu = 0dBFS
(14dB Headroom).
Internal trim controls allow you to reconfigure either (or both) of the sensitivity levels.
10
grace design
m
201 owner’s manual
Four standard sensitivities are supported in the m201 A/D converter:
+18dBu = 0dBFS
(14dB Headroom)
+20dBu = 0dBFS
(16dB Headroom)
+22dBu = 0dBFS
(18dB Headroom)
+24dBu = 0dBFS
(20dB Headroom).
The front panel interface features a calibration mode that allows precise adjustment of the A/D sensitivity. To recalibrate one or both of the input sensitivity configurations, simply do the following:
1. Disconnect AC power from the m201.
2. Remove the 8 top cover screws using a #2 Phillips screwdriver. Lift the top cover off the unit and set it aside.
3. Reconnect AC power to the m201 and turn it on.
4. Connect a signal generator to the A/D LINE inputs. Set the signal generator output to +4dBu @
1kHz (1.29V rms).
5. Turn on the m201 A/D converter and select LINE as the A/D input source.
6. To enter CAL mode, press and hold the INPUT SENS button for approximately 3 seconds. The normal operation displays will extinguish and the CAL indicator will begin flashing indicating CAL mode is active. The current input sensitivity range (A) or (B) will be illuminated along with that range’s current sensitivity calibration (shown as “dB Headroom” in the bottom left of the meter display).
7. Press and release the INPUT SENS button to select the range (A) or (B) that you wish to calibrate.
8. Press and release the A/D SOURCE button to scroll through the 4 available sensitivities until the desired setting is illuminated.
In calibration mode, the digital audio meter is configured such that the “0” position is the target sensitivity level. The meter then indicates the current signal level versus this target sensitivity. The meter will display a window centered around the target sensitivity with a +/- 0.4dB width (in 0.1dB increments). When the sensitivity adjustment on the A/D converter is calibrated for the selected setting, only the “0” LED will be illuminated. If the signal level is high, the 0 indicator will be illuminated along with the error (in 0.1dB increments) to the right of 0. If the signal level is low, the 0 indicator will be illuminated along with the error (in -0.1dB increments) to the left of 0.
On the m201 A/D module, trim pots are used to adjust the (A) and (B) ranges for each channel. Each of these are labeled on the A/D module circuit board <figure 3>.
1. Locate the appropriate trimmer for the channel you wish to adjust. If the current signal level is high, you need to decrease the A/D sensitivity. Using a non conductive tool, turn the appropriate trim pot counter-clockwise to reduce the level until only the “0” is illuminated on the m201 meter.
If the current signal level is low, you need to increase the A/D sensitivity by turning the appropriate trim pot clockwise to increase the level until only the “0” is illuminated on the LED level meter.
2. Once all desired calibration adjustments have been made, press and hold the INPUT SENS button for approximately 3 seconds. This will exit CAL mode and return the A/D to normal operation. The new settings are now stored until future changes are made.
3. Power down the unit, disconnect the AC power and reinstall the top cover.
grace design
m
201 owner’s manual
11
1 5 C
0 1 U 3 4 C
0 5 C
C 2 4
C 2 6
CH2 (B):
VR4
6 1 U 5 1 U
CH2 (A):
VR3
8 4 C
5 3 R
G R A
A T 1 3 6
C E
R E V
D E S I G N
4 5 C
1 4 R
4 3 R
4 Q
D 8
R 2 8
C 3 0
1 n i P
2 1 C
5 1 R
4 1 R
R 4
3
4
R
4 2
C 4 5
C 4 7
CH1 (B):
VR1
<figure 3 - A/D sensitivity trim pot locations>
CH1 (A):
VR2
Maintenance
The model m201 was designed to be maintenance free for many years. It is highly unlikely that your unit will require service. However, there are two adjustments that may need to be made from time to time. These procedures can be made by a qualified service technician or at the Grace Design factory.
PEAK LED ADJUSTMENT PROCEDURE
The peak LED threshold levels may be adjusted to a user defined operating level. This circuit is set at the factory with the green threshold at -14dBu and the red threshold at +16dBu. The relationship between the two thresholds is fixed. The procedure for adjusting the green / red threshold follows:
EQUIPMENT NEEDED
• Sine wave audio signal generator or oscillator output from a mixing console.
• Audio level meter or an RMS Volt meter with dBu or dBm scales
• Plastic alignment tool or small screwdriver
• Appropriate interconnect cables
• #2 phillips head screwdriver
PROCEDURE
1. With the power off, remove the eight phillips head screws from the top cover and remove it from the m201.
12
grace design
m
201 owner’s manual
2. Set all of the gain controls to the 30dB position.
3. Connect the audio generator to the input of channel 1.
4. Set the generator output level to approximately -20dBu @1KHz.
5. If the generator has an unbalanced output, refer to figure 2 below for termination information
6. Connect the level meter to the output of channel 1.
7. If the level meter has an unbalanced input, refer to <figure 1> for unbalanced output termination information.
8. Apply power to the generator, preamplifier, then the level meter.
9. Adjust the generator output level so that the preamplifier output level is at the desired red threshold. If the proper level can’t be reached, adjust the preamplifier gain control.
10. Locate VR2A (VR2B for channel 2) (see <figure 3>) on the channel 1 audio circuit board and adjust until the peak LED is between green and red. The color should appear amber when the setting is correct. Repeat this procedure for channel 2.
11. If it is desired to calibrate the peak indicator to a specific converter/recorder input level, simply connect the output of the preamplifer to the converter/recorder. Adjust the signal generator so that the desired peak level is indicated on the recorder and then adjust VR1 until the peak LED is between green and red.
INPUT OFFSET ADJUSTMENT
The input amplifiers in the m201 are ultra-precision laser trimmed devices which have a very low input offset. However, even the smallest differential offset at the input can result in an audible “click” when the gain control is turned. It should be noted that this type of click will be audible when no signal is present. With no signal present there is no signal amplitude to be changed unless input offset is present. This procedure nulls the input offset and minimizes the clicking sound with no signal present. In contrast, there will almost always be an audible click if turning the gain control while a signal is present. This is because the gain control, being a stepped control, will make an instantaneous change in amplitude when turned, which creates a transient signal.
EQUIPMENT NEEDED
• DC Volt meter with at least 1mV sensitivity
• Plastic alignment tool or a small screwdriver
• #2 phillips head screwdriver
PROCEDURE
1. Remove the 8 phillips head screws from the top lid but leave the lid in place.
2. Set all of the preamplifier gain controls to maximum.
3. Turn on the m201 preamplifier and allow to warm up for at least 45 minutes.
4. Remove the top lid and locate the DC offset test points TP1A and TP2A (see figure 4 below). Place the Volt meter probes into these holes.
5. Locate DC offset potentiometer VR1A (VR1B for channel 2) and rotate it for a reading of 0.000VDC
+/- 0.003V.
6. The input offset does drift with temperature and having the lid off will allow the circuitry to cool. It is advisable to replace the lid and let the preamplifier warm up again (about 20 minutes) and then re-check your adjustments.
grace design
m
201 owner’s manual
13
D1A D4A D1B D4B
OFFSET TRIM POTS:
CH1> VR1A
CH2> VR1B
K1A
K3A
D3A
K5A
P2
VR1A
R49A
Q4A
P4
K1B
K3B
D3B
K5B
P5
VR1B
R49B
Q4B
P8
OFFSET TEST POINTS:
CH1> TP1A-TP2A
CH2> TP1B-TP2B
PEAK LED CAL POTS:
CH1> VR2A
CH2> VR2B
U3A U3B
C6A
C5A
TP3
-15
C12
TP4
+15
C17
C20A
C19A
J7A
R40A
U8A
R59A
C39A
C6B
C5B
C51 C53
C20B
C19B
R40B
J7B
U8B
C36B
R59B
J1A J1B
U12 U13
R4A
R3A
R9
C1AR
P1
C8
C10A
C4A
U2
J3A
RED WIRE
U4
D9A
R30A
U1A
C13A
R20A
R19
C14
J4A
C25A
C24A
D7A
D8A
R29A
R28A
C27A
R27A
R26A
R25A
C23A
C22A
R38A
R37A
D10A
U7A
U6A
U5A
U10A
C45A
R63A
C44A
R62A
D17A
D16A
R53A
C35A
D13A
C43A
C42A
R61A
R51A
D14A
CHANNEL 1
C50
C10B
C1B
C4B
R4B
R3B
R70
U1B
J3B
CHANNEL 2
R21B
R20B
R71
C52
C13B
P7
D9B
R30B
R31B
C25B
C24B
D7B
D8B
R29B
R28B
R26B
R25B
C23B
C22B
R38B
R37B
D10B
U7B
U6B
U5B
RED WIRE
U10B
C45B
R63B
C44B
R62B
D17B
D16B
R53B
C35B
D13B
C43B
C42B
R61B
R60B
R52B
R51B
D14B
J4B
FRONT PANEL
<figure 4 - offset test point and peak LED adjust trim pots>
14
grace design
m
201 owner’s manual
CLEANING
Your m201 preamplifier chassis is constructed out of high quality stainless steel. Under normal circumstances, virtually no maintenance is required to keep the unit looking shiny and new. However, if your unit becomes smudged or dirty, here are some cleaning tips: We recommend using either
Pledge furniture polish or Zep brand stainless steel cleaner (available at the hardware store). Apply cleaner to a clean, dry, lint free cloth and gently wipe all stainless surfaces, taking care not to allow the cleaning product to build up around the panel switches or knobs. grace design
m
201 owner’s manual
15
Specifications
preamplifier specifications (without A/D converter)
Frequency Response
@ 40dB gain ± 0.2dB (50Ω source)
@ 40dB gain ± 3dB (50Ω source)
THD+N
@ 20dB gain +25dBu out, 1kHz
@ 40dB gain +25dBu out, 1kHz
@ 60dB gain +25dBu out, 1kHz
Intermodulation Distortion
@ 40dB gain +25dBu out
SMPTE/DIN 1:1 (50Hz, 7kHz)
SMPTE/DIN 4:1 (50Hz, 7kHz)
Noise - Referred to Input
@ 60dB gain 50Ω source
@ 60dB gain 150Ω source
@ 60dB gain 600Ω source
Phase Deviation
100Hz-20kHz @40dB gain
Crosstalk
Any Channel @ 40dB gain 1kHz
Any Channel @ 40dB gain 10kHz
CMRR
@ 60dB gain, 3.5Vcm, 1kHz
@ 60dB gain, 3.5Vcm, 10kHz
Maximum Output Level
1kHz, 100KΩ load
Impedance
Input
Input, ribbon mode
Output
Peak Led Meter
Green threshold
Red threshold
Weight and Dimensions dimensions weight
Power Consumption
100/120/230/240V~ 50-60Hz
16
grace design
m
201 owner’s manual
18Hz-65kHz
4.5Hz-350kHz
<.0008%
<.0009%
<.0070%
8100Ω
20kΩ
190Ω
-14dBu
+16dBu
2U, 19” rack mount x 10” deep
16.5lbs (7.5kg)
20 Watts Max
<.0020%
<.0030%
-130dB
-127dB
-123dB
<3°
-125dB
-115dB
>70dB
>70dB
+28dBu
A/D module specifications (line input)
Dynamic range
20Hz-20kHz
“A” weighting
THD+N
1kHz, -1dBFS, 20Hz-22kHz
Frequency response
44.1kHz Fs
48kHz Fs
88.2kHz Fs
96kHz Fs
176.4kHz Fs
192kHz Fs
Full scale input level
CMRR
60Hz
1kHz
10kHz
IMD SMPTE 4:1 60Hz, 7kHz, -3dBFS
Interchannel crosstalk
+/-0.2dB
5Hz-21kHz
5Hz-23kHz
5Hz-41kHz
5Hz-45kHz
5Hz-54kHz
5Hz-59kHz
Group delay
44.1-48kHz
Sample rates, internal crystal (kHz)
External Clock Lock Range
Wide lock mode s-Lock™ mode
Intrinsic Jitter, 200Hz-20kHz BW
Wide lock mode s-Lock™ mode
Jitter Rejection Corner Frequency
Wide lock mode, -3dB, 12dB/octave s-Lock™ mode, -3dB, 12dB/octave
A/D sensitivity
Range A
Range B
*
can be calibrated for any setting between +18dBu = 0dBFS and +24dBu = 0dBFS
>115dB
>117dB
< 0.00026% (-112dB)
-3dB
22kHz
24kHz
44kHz
48kHz
72.5kHz
79kHz
+16dB or +24dB (+/-2dB trim)
>65dB
>80dB
>60dB
<100dB (0.0008%)
<120dB
13/Fs
44.1, 48, 88.2, 96, 176.4, 192
40.1kHz-207kHz (+/-8% at each sample rate)
+/-250ppm (+350, -400ppm typical)
< 60ps RMS
< 40ps RMS
800Hz
10Hz
+22dBu = 0dBFS (18dB headroom*)
+18dBu = 0dBFS (14dB headroom*) grace design
m
201 owner’s manual
17
Signal Flow Diagram
18
grace design
m
201 owner’s manual
Warranty Information
Grace Design warrants all of our products to be free of defective parts and workmanship for a period of five years.
This warranty period begins at the original date of purchase and is transferable to any person who may subsequently purchase the product during this time.
This warranty excludes the following conditions: normal wear and tear, misuse, customer negligence, accidental damage, unauthorized repair or modification, cosmetic damage and damage incurred during shipment.
During the time of this warranty, Grace Design will repair or replace, at its option, any defective parts or repair defective workmanship without charge, provided the customer has appropriate proof of purchase and that the product has its original factory serial number.
Customers within the US are responsible for all inbound freight charges to Grace Design's facility, while Grace Design will pay for return freight charges via ground service. Customers outside the US must contact their distributor for warranty / product return details.
In order for Grace Design to provide efficient and timely warranty service, it is important that you mail the completed warranty registration card enclosed with all of our products within 10 days of the original date of purchase. You may also register your product directly with Grace Design by telephone
(303-443-7454 Monday-Friday 9:00am to 5:00pm MST), or you can register your product online at www.gracedesign.com.
This warranty is in lieu of all other warranties whether written, expressed, or implied, INCLUDING ANY
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. In no event will Grace
Design be liable for lost profits or any other incidental, consequential or Exemplary damages, even if
Grace Design is aware of the possibility of such damages.
In no event will Grace Design's liability exceed the purchase price of the product. This warranty gives the customer specific legal rights. The customer may also have other rights, which vary from state to state. Some states do not allow limitations on implied warranties or consequential damages, so some of the limitations of the above may not apply to a particular customer.
grace design
m
201 owner’s manual
19
Manual Revisions
D
E
B
C
F
B
B
B
Revision Page Change
A Initial release
3
4
6
Changed voltage range and power specifications
Power switch description changed to standby switch.
Added power mains disconnect information
7
5
13
9-12
7
Added signal flow diagram
Added A/D module infirmation changed fuse values for 220V-250V from 250 to 315mA
Fixed rearpanel A/D panel illustration
Changes Fuse Table values, formatting
Date Initials
04/25/2007 mbg
04/26/2007 mbg
04/26/2007 mbg
04/26/2007 mbg
04/26/2007 edg
11/08/07 edg
4/24/08
4/15/09 edg edg
4/9/2012 edg
20
grace design
m
201 owner’s manual
advertisement
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Related manuals
advertisement