Boulder 850 200 W Mono Power Amplifier Owners Manual 11/25/05 Boulder Amplifiers, Inc. 3235 Prairie Ave. Boulder, CO 80301 www.boulderamp.
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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
APPENDIX Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2 Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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 ma
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
NOTES 5-3 APPENDIX