Boulder 3050 User manual

3050 Mono Power Amplier
Owners Manual
11/21/2011
Boulder Ampliers, Inc.
3235 Prairie Ave.
Boulder, CO 80301
www.boulderamp.com

Getting StartedOperationRemote ControlBoulderlinkFault ConditionsAppendix
2

3
Congratulations and thank you for selecting the Boulder 3050 Mono Power
Ampliers for your high-performance music system. We are certain they
will provide you with years of listening pleasure.
The 3050s represent the concerted efforts of numerous Boulder craftsmen,
designers, engineers, and technicians working to bring you the very nest
audio playback components in the world. These Ampliers are the pinnacle
of Boulder’s product line which only a select few owners will be privileged
to experience.
Please take a few minutes to read through this owner’s manual prior to
using your 3050s. This will help you to understand the basic functions and
outstanding capabilities of the ampliers. It will also allow you to maximize
the exceptional performance for which they were designed.
Your Boulder 3050 Mono Power Ampliers, Serial numbers 0003 (L)
and 0004 (R), have undergone an extensive laboratory tests for safety,
functionality and technical performance. In addition, your ampliers have
been individually subjected to rigourous listening trials in our listening
room, utilizing a wide range of musical material. No amplier ever leaves
our factory until we are totally satised it is capable of achieving its full
potential as designed.
Boulder Ampliers, Inc.
Thank You

Getting StartedOperationRemote ControlBoulderlinkFault ConditionsAppendix
4

5
Getting Started 1-1
Placement of the 3050 Mono Power Amplier 1-1
Connecting To The Mains Outlet 1-1
Connecting to a Balanced Source 1-3
Connecting to an Unbalanced Source 1-3
Polarity 1-5
Connecting Your Loudspeakers 1-5
Operation 2-1
Powering Up 2-1
Input DC Offset Voltage Detection 2-3
Clip Detection 2-3
Thermal Protection 2-3
Maintenance 2-3
Remote Control 3-1
Remote Control Operation 3-1
Boulderlink 4-1
Connecting The Boulderlink 4-1
Setting Boulderlink Switches 4-1
Setting Boulderlink ID Numbers 4-3
Power Up By Boulderlink 4-3
Boulderlink Messages 4-5
Fault Conditions 5-1
Fatal Errors 5-1
Appendix 6-1
Specications 6-1
Troubleshooting 6-3
Notes 6-5
Table of Contents

1-1
Placement of the 3050 Mono Power Amplier
Your Boulder 3050 Power Amplier is designed to reduce interference
from external magnetic and radio elds (RF). While placement is not
critical, known magnetic elds should be avoided.
An isolated granite base has been included with the Boulder 3050.
The granite base is intended to serve as a platform on which to place the
power amplier. Choose a solid stable surface for the granite base and
amplier. The granite base should be selectively located prior to placing
the amplier on it. Moving these components will require at least four
people, as they are very heavy. Professional movers are recommended.
The 3050 Mono Power Amplier will generate some heat. Therefore,
it should be located in an area with ample air circulation. Specically,
be certain that the heat sinks are unobstructed by objects that could
potentially block air-ow.
You may want to have access to the rear panel for cable changes. It
is recommended that speaker cables be as short as possible, while input
cables can be as long as necessary.
Connecting To The Mains Outlet
Your 3050 Mono Power Amplier is supplied with a mains power
cable suitable to the location where it was purchased. It is constructed of
large enough wire gauge and a plug appropriate for 240v AC line voltage.
Do not substitute another power cable.
Exact voltage and frequency compatibility is stated in the
specications section.
Once the 3050 Power Amplier is connected to a live mains outlet, an
outline of the power button on the front panel will become illuminated and
blink for a short time. The outline will then glow white steadily, indicating
that the supervising microprocessor is powered up and the amp is ready to
be turned on.
Getting Started
Getting Started

1-2
Getting Started
Getting Started

1-3
Getting Started
Getting Started
Connecting to a Balanced Source
To fully realize the sonic potential of your 3050 Mono Power Amplier,
use balanced connections. Balanced cables minimize interference from
magnetic and RF sources.
Connect your preamplier output to the input provided on the rear
panel of the 3050.
Connecting to an Unbalanced Source
Although the inputs are of the 3-pin type, an unbalanced source is
easily accommodated by using a special cable. This cable has an RCA
type connector on the source end, and a 3-pin connector for going to the
input of the 3050 Power Amplier.
The minus input (pin 3) should be wired to ground only at the RCA
connector. This brings the minus input reference of the 3050 to the
unbalanced source ground, thus reducing loops.
Another option for accommodating unbalanced sources is that of
the Boulder ABL2 Input Adapter. It converts a balanced input into an RCA
input right at the rear panel of the 3050.
Like the above cable, the minus input of the 3050 is connected to
the ground of the RCA connector. However, this minus side will then share
the shield wire with the chassis ground and will not have very good hum
rejection.

1-4
UNBALANCED INPUT CABLE
3-NEG INPUT
2-POS INPUT
1-GROUND
Getting Started
Getting StartedGetting Started

Getting Started
1-5
Polarity
Please note that the 3050 Mono Power Amplier conforms to the
standard of pin 2 as the “high” or “hot” pin for the balanced input.
The Polarity of the 3050 Mono Power Amplier is such that a
positive-going transition at pin 2 will produce a positive-going transition at
the “+” output terminal.
Connecting Your Loudspeakers
Do not use any wrenches on the loudspeaker binding posts. Tighten
these connectors only by hand.
WARNING: This is a high-power amplier. When driven, there is high
voltage potential at the terminals. Connections should be made with the
mains disconnected.
Select spade terminals which accept 6 mm or .250 inch diameter
binding posts. Two sets of output connections are provided to enable easy
passive biamping.
There is no provision for the use of banana plugs. These plugs
have been proven to come loose over time which increases the contact
resistance and distortion. For the same reasons we also do NOT
recommend the use of banana plugs at the speaker end.
Getting Started
Getting Started

1-6
Getting Started
Getting Started

Operation
2-1
Powering Up
With all your connections made, you are ready to listen to your
Boulder 3050 Mono Power Amplier.
To turn the amplier on, press the POWER button on the front panel.
The amplier will perform a warm up cycle and the power-button indicator
will blink white and red. This power up sequence is mandatory and cannot
be avoided.
Because of the large inrush currents associated with the powerful
quadruple Toroidal transformers, eight power relays are used to turn on
the amplier. These are under control of the supervising microprocessor.
During the power up sequence, you will hear four sets of two relay clicks,
separated by intervals of two seconds.
The indicator will then steadily glow white and remain this way to
indicate normal operation.
To turn the amplier off, press the POWER button again. The
indicator will then slowly and continuously change from white, to dark, and
back to white. This indicates that the amplier is in “Stand-By” mode.
Operation

Operation
2-2
Operation

Operation
2-3
Input DC Offset Voltage Detection
The Boulder 3050 Mono Power Amplier is a direct-coupled power
amplier with a servo for zeroing out any DC voltage offset coming from
the preamplier or other sources connected to the amplier’s input.
If this input DC is sufcient to cause three volts or more at the
output, a loudspeaker protection circuit will mute the amplier output
by electronically disconnecting itself from the loudspeaker. The power
indicator will turn red. This condition will continue until the DC is removed.
If the indicator remains red, it is recommended that the user correct
the DC offset of the source device before continuing.
Clip Detection
Clipping of the waveform results when any amplier is driven at too high a
level. A clip detection circuit is included in the 3050 Mono Power Amplier.
The indicator will indicate clipping by momentarily turning from
white to red. Both voltage and current modes of clipping will be detected,
although generally it is only voltage clipping which occurs.
Thermal Protection
A thermal protection circuit prevents high case temperatures which
are unpleasant to touch and potentially harmful to the amplier. The
thermal cutout circuit will mute the amplier when the transistor cases
reach 85°C, and the indicator will turn red.
If this happens, more ventilation should be provided for the amplier.
Maintenance
No routine maintenance is required for the Boulder 3050 Power
Amplier. However, to keep the operating temperatures at a minimum, do
not block the heat sink ns, and remove any dust buildup that may occur.
Operation

Operation
2-4
Operation

Remote Control
3-1
Remote Control Operation
Operation of the Boulder 3050 Mono Power Amplier by remote
control is possible by use of a Boulderlink cable to a Boulder preamplier.
When Boulderlink is connected correctly, the 3050 will turn on and
off with the preamplier. Moreover, the Boulder 3050 is capable of issuing
on/off commands to all other Boulder equipment attached by Boulderlink,
including it’s paired amplier.
Remote Control

Remote Control
3-2
Remote Control

Boulderlink
4-1
Boulderlink is a means of interconnecting most of Boulder products
so that their microprocessors can talk to each other, pass important
information, and issue commands. Among the key features, Boulderlink
allows sequential initiation of power ampliers’ and other products.
Boulder power ampliers can send messages to Boulder preampliers
which are then shown on its display.
Connecting The Boulderlink
Turn off all Boulder products which are to be linked before connecting
Boulderlink cables and setting the Boulderlink ID and Master/Slave
switches.
Boulderlink cables in various lengths are available as an accessory
from you Boulder dealer. Two connectors are provided on the rear panel of
the 3050 and other Boulder products.
All the chassis are connected together in a daisy chain manner. Start
by connecting one chassis to another —then from that chassis to the next
until all are connected. The order does not matter.
A special interface may be obtained to enable Boulderlink to be used
with other control systems. Contact your Boulder dealer for more details.
Setting Boulderlink Switches
Every Boulderlink system must have one, and only one “MASTER”
component. Usually this is the preamplier. In the case of the 3050 Power
Amplier, one channel should be set to “MASTER” as long no preamplier
is connected by Boulderlink. Other Boulderlink products which do not have
a MASTER/SLAVE switch are not eligible to be “MASTER”.
Boulderlink

Boulderlink
4-2
BOULDERLINK "DAISY CHAIN"
TO ALL
OTHER
SLAVE
UNITS
BOULDER
PRE-
AMPLIFIER
BOULDER
POWER
AMPLIFIER
BOULDER
POWER
AMPLIFIER
MASTER SLAVE SLAVE
Boulderlink

Boulderlink
4-3
Setting Boulderlink ID Numbers
Every component is required to have a unique Boulderlink ID number.
Each Boulder 3050 Mono Power Amplier has an amplier ID switch
on the rear panel. Starting by setting the rst switch to “0” or “1” by
pressing on the either button above or below the ID window. Once the
rst amplier is set at either “0” or “1”, assign other ampliers numbers,
moving up in sequence without duplication. Use of the lowest numbers will
hasten the turn on processor, as each amplier is allowed three seconds
to initialize before the next. This spreads out the power line inrush currents
preventing the house circuit breakers from unnecessarily tripping. Up to
16 power ampliers may be connected together in one Boulderlink daisy
chain.
Power Up By Boulderlink
With each component connected together with a Boulderlink cable,
and individually connected to a mains outlet, pressing the power amplier
or preamplier’s “STANDBY” push button will initiate the turn on sequence
of all components.
The rst time a master is powered up, it will search for any “SLAVE”
units connected to it. As the MASTER nds each SLAVE, the SLAVE’s ID
number will be shown on the display.
If any of the connected SLAVEs are ampliers, then each time the
MASTER is turned on it will display “WAITING FOR AMPS.” Each amplier
will be turned on in the order of their Boulderlink ID. To minimize turn on
time, the amplier’s ID should be set to the lowest possible number in the
sequence. For example, use “0”, “1”, and “2”, instead of “13”, “14”, and
“15”. An Amplier set to ID “15” will take 47 seconds to turn on.
Boulderlink