Dangerous Music Master Manual instruction

The Dangerous Music Master
setup and operation manual
The Dangerous Music Mastering controller represents the culmination of the design and
implementation of custom mastering equipment in many of the worlds top mastering
studios by the designers at DMI. Fifteen years of experience have been distilled down to
a two rack space unit of exceptional ergonomic and sonic performance at a price about a
third of the designer’s previous attempts. In conjunction with the Dangerous Music
Monitor, the addition of one’s favorite analog processing equipment and A/D/A
converters, the Master makes the setup of a quality analog mastering system easier than it
has ever been. This manual explains the features, controls, connections, and suggestions
for the operation of this unit.
Introduction 1
Safety Review 2
Overview 3
Rear panel connections 4
Front panel controls 5
Internal jumpers 6
Specifications 7
1

Safety Review
Certain precautions should be taken when using electrical products. Please observe the
safety hints by reading the manual and obtaining qualified help if necessary to adhere to
the precautions. The power supply must be switched to the proper mains voltage.
Please check the red window on the power supply to verify the correct setting.
1. Always use a properly grounded power supply cord with this product. Please
do not defeat the ground pin on the mains plug. This connection provides earth to
the chassis and signal grounds inside the device for clean and quiet operation. The
“Internal jumpers and adjustments” page can help clear up a buzz problem if one
develops.
2. Avoid high temperature operation in equipment racks by providing air
circulation. The number one killer of electronic gear is HEAT. The life
expectancy of electrolytic capacitors (the usual casualty in a heat situation) goes
from 10 or 15 years to 10 or 15 weeks if the temperature inside the box is allowed
to rise beyond 140 degrees F. Vented rack panels may look like wasted space to
an interior decorator, but they look like beauty to a technician or equipment
designer! If the front panel is hot, it is roasting inside the box.
3. Avoid areas of high magnetic fields. The steel chassis of Master is designed to
shield the circuits from EMI and RFI (magnetic and radio interference). When
installing equipment in racks, it is prudent to put power amplifiers and large
power supplies at least several rack spaces, if not in a different rack, away from
equipment that deals with low level signals. Separation of high level and low level
equipment can pre-empt trouble caused by heat and EMI.
4. Care should be taken to avoid liquid spills around equipment. If a spill occurs,
please shut off the gear. A qualified technician should investigate accidents to
prevent further equipment damage or personnel hazards caused by spills.
5. Every attempt has been made by the designers to provide versatility in the set-
up and calibration of Master. As such, there ARE user serviceable jumpers and
calibrations inside. If one is uncomfortable with opening gear and changing
jumpers or making adjustments, please seek qualified help if necessary.
6. If adjustments or jumper changes are required, please unplug the power before
opening the top. Dropped screws or tools on a live circuit board can manifest
themselves as burn marks and smoked components. While we feel your pain,
(been there) subsequent damage is not covered by the warranty.
Dangerous Music Incorporated reserves the right to change the specifications or modify the designs of its
equipment. Sending in the registration card is our way of keeping in touch with users of our equipment
should this become necessary. Registration information is always kept confidential and never disclosed to
third parties for any reason. DMI wishes that the contents of this manual not be disclosed to third parties
without the consent of the designers. 2

Overview
The Dangerous Master is easy to set up and use. It is designed to be the platform that
turns a few pieces of analog outboard processing gear, a D/A or analog source, and an
A/D hooked up to an editing computer, into the backbone of a mastering rig.
An analog source is fed to the input where the input gain control let’s one precisely set
the level and balance into the insert stack.
Your favorite analog processing gear is hooked up to the inserts. When an insert button is
pressed, that loop is in line. The second loop can work in stereo or “Sum and Minus”
mode. In S&M, one can alter the center pan information of a mix without affecting the
sides and vice versa. For instance, the lead vocal is too bright but the guitars panned to
the sides are dull? Use stereo EQ in S&M to fix both problems! This kind of processing
makes a mastering engineer so equipped “King of the Mountain”. The Width control
allows adjustment of the stereo image width. It works even when Insert 2 is not pressed
when S&M is selected. Remember, while S&M is fun, too much can be a bad thing!
The writer’s favorite suggested processing goes like this:
Insert 1 gets a stereo EQ to set the tone correct for the rest of the stack.
Insert 2 gets a parametric EQ, De-Esser, and Limiter to fix any problem with a mix.
Insert 3 gets a Compressor to control dynamic range for loudness.
The Output Gain control let’s one precisely ‘hit’ the A/D converter at the correct level.
The Input/Output Monitor Selector let’s one compare the dry and processed signal and
there is an Input Monitor Offset control so that comparison can be made even after
adding several dB of loudness to the mastered signal. This also allows an easy way to tell
how much apparent loudness has been added to the signal (by matching the apparent
levels and reading the difference on the IMO gain control).
3

Rear panel connectors
An analog source is fed to the input connectors. There are two sets, selectable by the ‘IN
1-2’ switch on the front panel. This makes it easy to have a D/A normaled to the first
input and the second input wired to a patchbay or tape machine.
The inserts are to include analog processing equipment. It has been found by the authors
after extensive experimentation that 3 insert loops provide the correct number of insert
points verses the minimum number of relays to get the job done. More equipment is
accommodated by ‘ganging’ as explained on the previous page. The insert points can be
run to a patchbay if the added flexibility of patching is needed (to re-route the order of
processing for instance). More connectors and cable may not equal better sound quality.
There are 2 ‘Main outputs’ to feed A/D converters, a tape machine, or patchbay
depending on the user’s preference. The authors use 2 different A/D converters to select
the best one for ‘flavor’ depending on the program material.
The ‘Monitor’ output feeds the Dangerous Music Monitor. The input signal (post Input
level and Input Monitor Offset level controls) or the output signal (post processing) will
be sent to the Monitor depending on the position of the ‘Mon Out’ switch on the front
panel.
The ‘AC IN’ connector goes to the power supply. Please check that the supply is off
before plugging in this cable. Hot plugging will result in burned contacts.
The ‘CHASSIS’ and ‘GROUND’ banana jacks are strapped together at the factory. The
strap may be removed to isolate the chassis and audio grounds. The jacks can be used to
quiet down a troublesome piece of audio equipment (Sontec) with a ground wire if
necessary.
4

Front Panel controls
The Input Level Controls let the engineer set precisely, the operating level and balance
that will go through the equipment selected by the Insert buttons. The range is 10 dB in
0.5 dB steps.
The top row of buttons under ‘Functions’ select the following:
1. ‘IN 1-2’ selects which input is processed.
2. ‘S&M’ selects whether or not Insert 2 is in Stereo or Middle Sides mode.
3. ‘OUT MON’ selects whether the Monitor Output jacks have the Input or Output
signal sent to the monitor section.
The Input Monitor Offset level control adjusts the level of the Input Monitor. This is very
handy to match the input and output levels to listen to the effect of processing without the
level difference clouding one’s judgment. The engineer can also match input and output
level, look down at the scale, and determine the relative gain obtained from the mastering
process. This control has a scale of -2 to +8dB in 0.5 dB steps.
The S&M width control adjusts the stereo image width when the S&M button is pressed.
Please note that activating S&M without ‘Insert 2’ selected still passes audio through the
matrix.
The Output level control let’s one set the final level presented to the A/D converter. The
range is 10dB in 0.5 dB steps.
The level controls are all stepped attenuators for accuracy, repeatability, and highest
sound quality. The attenuators are built with what we feel are the highest quality switches
and resistors available at any cost. It is useful to gently ‘run the switches through’ their
travel every so often to spread the lubricants around inside and wipe the contacts clean.
This helps keep the switches quiet. The use of contact cleaners is not necessary and will
damage the switches by washing the grease out.
5

Internal Jumpers and Adjustments (please see step 5 on page 2)
The motherboard has input cable shield ground selection jumpers to accommodate
different grounding schemes. It is recommended that all electrical equipment in the studio
is properly grounded by making sure that power cables have 3 pins and that the third pin
is connected to ground. The use of ‘ground lifts’ to clear up a buzz problem is frowned
upon by the international consortium of electrical safety agencies. If a ground noise
problem occurs, it may be cleared up by switching the jumper position on the connector
associated with the piece of gear that is having the buzz problem.
The shield lift headers have 2 posts. A jumper placed over both posts connects the chassis
ground to the cable shield. To lift a shield, pull the jumper off of the posts. It is a good
idea to put the ‘unused’ jumpers on one of the posts to keep from losing the jumper.
Master should not need to be calibrated but in case it does, here is the procedure:
1. Obtain a calibrated oscillator and level measuring device. These should be lab
quality (HP, Tektronix, Neutrik, Audio Precision, etc.)
2. Place the Master on a clean, well lit table with a pad under it to prevent scratches.
3. Remove the top to expose the motherboard for calibration.
4. Hook up the power supply and turn on the unit.
5. Set all controls to unity gain with all Function and Insert switches out.
6. Set the oscillator for +4dBu and plug into Input 1. Feed both channels.
7. Activate ‘Insert 1’ and measure the level coming out of the ‘Send 1’ jacks.
8. Adjust P1 and P2 to measure +4dBu.
9. Deactivate ‘Insert 1’ and adjust P3 and P4 to read +4dBu at ‘Main Output 1’.
10. Adjust P5 and P6 to measure +4dBu at the ‘Monitor Output’ jack.
11. Activate the ‘OUT MON’ function and adjust P7 and P8 to read +4dBu at the
Monitor Output jack.
12. Pull the right channel’s input. Activate the ‘S&M’ function. Adjust the ‘xtalk’ pot
for minimum signal at the Right output. The signal should null below -70dBu.
6

Master Specifications
Measurements made with a Neutrik AD-2 at a nominal operating level of +4dBu
Frequency response 10Hz- 100kHz within 0.15dB
THD+noise 0.003% band limited to 22kHz
IMD60 4:1 0.004%
Crosstalk rejection > 95 dB
Headroom > +27dBu
Dynamic range > 116 dB
Power consumption 40 watts 100-130, 200-250 volts user selectable
Warrantee 2 years parts and labor, subject to inspection.
Does not include damage from accident, abusive operation,
shipping, or modifications/attempted repairs by
un-authorized personnel.

7
Dangerous Music highly recommends the Mastering furniture built by Sterling Modular
Systems to facilitate installation. Please check out their website.