Boulder 850
200 W
Mono Power Amplifier
Owners Manual
11/25/05
Boulder Amplifiers, Inc.
3235 Prairie Ave.
Boulder, CO 80301
www.boulderamp.com
APPENDIX
BOULDER
LINK
REMOTE
CONTROL
OPERATION
GETTING
STARTED
Boulder 850 Power Amplifier Rear Panel
APPENDIX
BOULDER
LINK
REMOTE
CONTROL
OPERATION
GETTING
STARTED
TABLE OF CONTENTS
GETTING STARTED
Placement of the 850 Power Amplifier. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connecting to the Mains Outlet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connecting a Balanced Source. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connecting an Unbalanced Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Polarity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connecting your Loudspeakers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OPERATION
Powering Up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Clip Detection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Shorted Output Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermal Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
REMOTE CONTROL OPERATION
Remote Control Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12 Volt Trigger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
BOULDERLINK
Connecting the Boulderlink . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setting Boulderlink Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setting Boulderlink ID Number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Up via Boulderlink . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Boulderlink Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
APPENDIX
BOULDER
LINK
REMOTE
CONTROL
OPERATION
1-1
1-2
1-3
1-4
1-5
1-5
2-1
2-2
2-3
2-3
2-3
3-1
3-1
4-1
4-2
4-2
4-3
4-4
GETTING
STARTED
APPENDIX
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
APPENDIX
BOULDER
LINK
REMOTE
CONTROL
OPERATION
GETTING
STARTED
G ETTING STARTED
PLACEMENT OF THE 850 POWER AMPLIFIER
Your Boulder 850 Power Amplifier is designed to reduce interference
from external magnetic and radio fields (RF). While placement is not
critical, known magnetic fields should be avoided.
Because the power amplifier is heavy, a solid, stable surface should
be used.
As it will generate some heat, there should be good air circulation
around it. In particular, make certain that the heat sinks are not
blocked.
You may want to have some access to the rear panels for cable
changes.
It is recommended to keep the speaker cables as short as possible and
have the input cables as long as necessary.
1-1
GETTING
STARTED
CONNECTING TO THE MAINS OUTLET
Your 850 Power Amplifier is supplied with a mains cord suitable to
the location where it was purchased. It is constructed of a large enough
wire gauge and a cable plug appropriate for the voltage you intend to
use. Do not substitute another power cable.
The mains voltage and frequency of the amplifier is fixed by country
and can not be changed. Exact voltage and frequency compatibility is
stated in the specifications section.
Once the 850 Power Amplifier is connected to a live mains outlet, the
power switch can be switched on by pressing the ”–” part of the rocker.
Then the indicator will be illuminated. The indicator will be of varying
color, showing that the supervising microprocessor is powered up and
ready.
The power switch, which is part of the mains inlet, is a manual switch
used to totally disconnect to amplifier from the mains in a similar fashion
to disconnecting the power cord. If left in the on or ”––”) position, then
the amplifier can be turned on and off from the front panel STANDBY
pushbutton, by Boulderlink connection or by the 12V trigger.
1-2
GETTING
STARTED
CONNECTING A BALANCED SOURCE
To fully realize the sonic potential of your 850 Power Amplifier,
use balanced connections whenever possible. Balanced cables reduce
interference from magnetic and RF sources to an absolute minimum.
Connect your preamplifier output to the input provided.
1-3
GETTING
STARTED
CONNECTING 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
phono type connector on the source end and a 3 pin connector for going
to the input of the 850 Power Amplifier.
The minus input (pin 3) should be wired to ground only at the RCA
phono connector. This brings the minus input reference of the 850 to the
unbalanced source ground, thus reducing ground loops.
Another option for accommodating unbalanced sources is that of the
Boulder ABL2 Input Adapter. It converts a balanced input into a RCA
phono input right at the rear of the 850.
Like the above cable, the minus input of the 850 is connected to the
ground of the RCA phono. However, this minus side will then share the
shield wire with the chassis ground and will not have very good hum
rejection.
UNBALANCED INPUT CABLE
2-POS INPUT
3-NEG INPUT
1-GROUND
1-4
GETTING
STARTED
POLARITY
Please note that the 850 Power Amplifier conforms to the standard of
pin 2 as the high or hot pin for the balanced input.
The polarity of the 850 Power Amplifier 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 amplifier. When driven, there is a
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. One set 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.
1-5
GETTING
STARTED
O PERATION
POWERING UP
With all your connections made, you are ready to listen to your
Boulder 850 Power Amplifier.
To turn the amplifier on, press the STANDBY button on the front
panel. The amplifier will perform a warm up cycle and the indicator will
alternate between red and amber for 45 seconds. This power up sequence
can be skipped by pressing and holding the STANDBY button until the
indicator turns red; then release and it will start in about 5 seconds.
Because of the large inrush currents associated with the powerful
toroidal transformer, two power relays are used to turn on the amplifier.
These are under the control of the supervising microprocessor. During
the power up time, you will hear 2 sequential relay clicks.
The indicator will then turn amber and stay so during normal
operation.
To turn the amplifier off, press the STANDBY button again. The
indicator will continuously change from red to green.
2-1
OPERATION
CLIP DETECTION
Clipping of the waveform results when any amplifier is driven at
too high a level. A clip detection circuit is included in the 850 Power
Amplifier.
The indicator will indicate clipping by momentarily turning from
amber to red. Both voltage and current modes of clipping will be
detected, although generally it is only voltage clipping which occurs.
2-2
OPERATION
SHORTED OUTPUT DETECTION
If the output of the amplifier becomes shorted, the indicator will turn
red and the amplifier will turn off the output stage for about 3 seconds,
then very briefly try to turn on again. If the short still exists, this cycle
will repeat until the short is removed.
THERMAL PROTECTION
A thermal protection circuit prevents high case temperatures which
are unpleasant to the touch and potentially harmful to the amplifier. The
thermal cutout circuit will mute the amplifier when the transistor cases
reach 85°C, and the indicator will turn red.
If this happens, more ventilation should be provided for the
amplifiers.
MAINTENANCE
No routine maintenance is required for the Boulder 850 Power
Amplifier. However, to keep operating temperatures at a minimum,
do not block the heat sink fins, and remove any dust buildup that may
occur.
2-3
OPERATION
R EMOTE CONTROL OPERATION
Operation of the Boulder 850 Power Amplifier by remote control
is possible when connected by a Boulderlink cable to either the 810
Preamplifier, the 1012 DAC Preamplifier, the 1010 Preamplifier or the
2010 Preamplifier. A special Boulderlink adapter box called BLAB is
required to make the connector change from the 800 series to the 1000/
2000 series style connectors. It is available from your dealer.
When so connected the 850 Power Amplifier will be turned on and
off with the preamplifier in the sequence set by the ID switch. See page
4-2.
12 VOLT TRIGGER
The 850 Power Amplifier also provides a trigger input for remote on/
off operation with other brands of equipment. With a trigger connection,
the 850 will be on when the voltage is +5 to +12 volts, and off when the
voltage is 0 volts. The tip of the mini phone plug should be positive with
respect to the sleeve.
When 12 Volt Trigger is used, the 850 Power Amplifier will be turned
on in the sequence set by the ID switch. See page 4-2.
Boulderlink and the trigger input should not be used at the same
time.
3-1
REMOTE
CONTROL
B OULDERLINK
BOULDERLINK "DAISY CHAIN"
BOULDER
PREAMPLIFIER
BOULDER
POWER
AMPLIFIER
BOULDER
POWER
AMPLIFIER
MASTER
SLAVE
SLAVE
TO ALL
OTHER
SLAVE
UNITS
Boulderlink is a means of interconnecting most Boulder products
so that their microprocessors can talk to each other and pass important
information. Among the key features, Boulderlink allows sequential
initiation of power amplifiers’ and other products’ power up when the
preamplifier is turned on. Boulder power amplifiers can send messages
to Boulder Preamplifiers which are then shown on its display.
CONNECTING THE BOULDERLINK
Turn off all products to be linked before connecting Boulderlink
cables and setting Boulderlink ID and Master/Slave switches.
Boulderlink cables in various lengths are available as an accessory
from your Boulder dealer. Two connectors are provided on the back of
the 850 and other Boulderlink enabled 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 called BLIB may be obtained to enable Boulderlink
to be used with other control systems. Contact your Boulder dealer for
details.
4-1
BOULDER
LINK
SETTING BOULDERLINK SWITCHES
Every Boulderlink system must have one “MASTER” component,
and only one component can be set to MASTER. Usually this is the
preamplifier. Power amplifiers and other products not having a
MASTER/SLAVE switch are not eligible to be “MASTER.”
SETTING BOULDERLINK ID NUMBERS
Every component is required to have a unique Boulderlink ID
number.
Each Boulder 850 Power Amplifier has a thumbwheel switch on
the rear panel. Start by setting the first switch to 0 or 1 and then going
up from there without any duplication. Use of the lowest numbers
will speed up turn on as each amplifier is allowed about three seconds
before the next. This spreads out the power line inrush currents thus
preventing house circuit breakers from unnecessary tripping. Up to 16
power amplifiers may be connected together in one Boulderlink cable
daisy chain.
4-2
BOULDER
LINK
POWER UP VIA BOULDERLINK
With each component connected together with a Boulderlink cable,
and individually connected to the mains, pressing the preamplifier’s
STANDBY pushbutton will initiate the turn on sequence of all
components.
The first time a master is powered up, it will search for any “slave”
units connected to it. As the master finds each slave, the slave’s ID
number will be shown on the display.
If any of the connected slaves are amplifiers, then each time the
master is turned on it will display “WAITING FOR AMPS.” Each
amplifier will be turned on in the order of their Boulderlink ID. To
minimize turn on time, the amplifier’s Boulderlink IDs should be set
to the lowest sequential numbers possible. For example, use 0, 1, and 2
instead of 13 , 14, and 15. An amplifier set to ID 15 will take 47 seconds
to turn on.
4-3
BOULDER
LINK
BOULDERLINK MESSAGES
Each component in the system can send a message to the
preamplifier which is then shown on its display. This is particularly
helpful in confirming the operating status of each power amplifier in
a multiple amplifier system. Typical messages on an 810 Preamplifier,
1010 Preamplifier or 1012 DAC Preamplifier are as follows.
“AMPLIFIER 1 ERROR” means that an internal power supply has
failed and the amplifier has turned itself off to protect the speakers from
damage.
“AMPLIFIER 1 IS HOT” means that is has turned itself off due to a
higher than normal temperature condition on the heatsinks.
“AMPLFIER CLIP” means that the amplifier’s output has
momentarily reached its voltage limitation.
“UNIT 1 IS OFFLINE” means that the slave is no longer responding
via Boulderlink. Its Boulderlink cable may have become disconnected, or
the mains power has been disconnected.
“UNIT 1 IS ONLINE” means that the slave is now responding
via Boulderlink in a normal manner and has been recognized by the
master.
4-4
BOULDER
LINK
BOU L D E R 8 5 0 P O W E R A M P L IFIER SPECIFICATIONS
THD at Continuous Power, 20 to 2KHz
THD at Continuous Power, at 20KHz
Continuous Power, 8 Ω
Continuous Power, 4 Ω
Continuous Power, 2 Ω
Peak Power, 8 Ω
Peak Power, 4 Ω
Peak Power, 2 Ω
Magnitude Response, 20 to 20KHz
Magnitude Response, -3 dB at
Voltage Gain
Signal to Noise Ratio (re: 200W/8Ω)
Input Impedance
Common Mode Rejection (Balanced only)
Inputs
Output Connectors
Size, Inches, W X H X D
Power Requirements
All specifications taken at 120 VAC mains power
5-1
APPENDIX
0.0016%
0.009%
200 W
200 W
200 W
200 W
400 W
400 W
+0.00, -0.04 dB
0.015Hz, 150kHz
26dB
-109dB, unweighted, 20 to 22kHz
Balanced: 50KΩ, Unbalanced: 25KΩ
60Hz: 90dB, 10kHz: 70dB
3-pin Balanced
6 mm / .250 inch thumbscrews
8.5W x 7.38H x 15.25D, Speaker connectors add 1.50
Voltage is suitable for country sold in
50-60 Hz, 800 W at maximum
TROUBLESHOOTING
SYMPTOM
No power indication
Red power indication
Amber power indication, but sound not
heard from one channel
5-2
APPENDIX
CAUSE
REMEDY
Power switch is not on
Turn on power switch
Power amplifier is not plugged in
Connect to an AC outlet
Home circuit breaker is tripped
Reset circuit breaker
Low line voltage
Have line voltage checked
Power supplyʼs breakers tripped
Reset breakers on rear panel
Defective power supply cables
Have cables tested
Defective power supply or preamp
Return to dealer for service
No signal from one channel of source
Check source controls, cables, and
connections
One Channel is muted by balance control
Recenter balance on preamp
No signal out to power amplifier
Check connections to power amp
NOTES
5-3
APPENDIX