What would you like to do ? -------------------------- Help us find the most requested user's guides Upload your
user manual Search for a user manual Register Login and access your manuals Reset your password

	Browse all user guides
	The HALCRO LOGIC DM78 @@ DM88 product forum
	Upload your user manual
	Sign-up Log in
	Help us find the most requested user's guides
	Include the add-on to download manuals from your site, forum or blog
	Frequently Asked Questions
	Contact Diplodocs team
ALL GUIDES BY CATEGORY Domestic Appliance TV & Audio Car & Motorcycle Phone Computer Camera & Video Music Sport Gardening & Housekeeping Video Game & Software Jewelry & Watch Baby & Toys Hygiene & Health Other

1 Contents Introduction ................................................2 Important Safety Information...................3 Symbols ......................................................... 3 Electrical safety............................................. 4 Protection from fluids .................................. 4 Service warnings .......................................... 5 Protection from overheating ...................... 5 Lifting or moving ........................................... 6 Wiring to the loudspeaker terminals to Class 2 wiring (US wiring regulations) ....... 6 Output Current Limiting ..........................16 Output transistor protection...................... 17 Unusual output conditions.........................18 Power supply output current limiting .......18 Internal power supply protection..............18 Mains transient overload protection ........18 Input overload protection ..........................18 Amplifier inter-stage protection ................18 dm78 Specifications................................19 dm88 Specifications ...............................21 Care and Maintenance.......................... 24 Cleaning....................................................... 24 Additional Important Safety Instructions for US .......................................................... 7 Interference Warning - US FCC Regulations ................................................8 For Consumers within the European Union: ..........................................................9 Installation................................................. 10 Unpacking ....................................................10 Storing packaging .......................................10 Positioning ....................................................10 Troubleshooting...................................... 25 Service and Warranty Information ....... 26 Overview ..................................................... 26 Product warranty ....................................... 26 Exclusions to the warranty ....................... 26 Transferability.............................................. 27 Warranty verification .................................. 27 Warranty registration ................................. 27 If service is required ................................... 27 Transportation of products....................... 28 Freight damage claims.............................. 28 If you have moved ..................................... 28 Thank you for choosing Halcro!............... 28 Controls and Connections......................11 Connecting the loudspeakers ...................11 Connecting the external ground ...............11 Connecting the mains supply cable..........11 Break-in period.............................................11 dm78 Inputs .................................................12 dm88 Inputs.................................................13 Operation ................................................. 14 Electronic Protection and Reliability ..... 15 Components................................................15 2 Introduction Congratulations on purchasing the Halcro dm78 or dm88 monoblock amplifiers. Halcro designs and manufactures the only "Super Fidelity" amplifiers in the world. This "Super Fidelity" amplifier reproduces with better than 99.9997% purity of all tones across the entire audio range. The concept behind the electronic design was to create an amplifier that did not color the sound with its own electronic characteristics -- to recreate the original sound as it was at the time of recording. Please enjoy the Halcro audio experience. Halcro has enjoyed creating perfect audio reproduction for the world's music connoisseurs. If you desire to contact Halcro to give us feedback on your purchase or for general enquiries; Please feel free to contact us via: E-mail: admin@halcro.com Telephone: + 61 8 8238 0807 Facsimile: + 61 8 8238 0852 3 Important Safety Information Symbols The following symbols are used on this equipment: The lightning flash with arrowhead symbol, within an equilateral triangle, is intended to alert the user to the presence of uninsulated `hazardous voltage' that may be of sufficient magnitude to constitute a risk of electric shock to a person if exposed or contacted. The exclamation point within an equilateral triangle is intended to alert the user to the presence of important operating and maintenance (servicing) instructions in the following pages. The `CE' symbol indicates compliance of this device with the relevant directives of the European community including the EMC (Electromagnetic Compatibility) and LVD (Low Voltage Directive) standards. Warning of electrical shock hazard. Do not open cover (or back). There are no user serviceable parts inside. Refer servicing to qualified service personnel. This symbol is to indicate that the unit is heavy and that precautions are required when lifting or moving the unit. 120lb 4 Electrical safety WARNING: This product must always be connected to a mains socket outlet with a protective earth connection. Only use a suitable approved mains cord complying with European individual country requirements in the CE Low Voltage Directive Scheme. The unit should be installed in a position where the mains plug is easily accessible. Disconnect the unit from the mains if it is to be left unused for a long period. WARNING: No naked flame sources, such as lighted candles, should be placed on the unit. If naked flame sources tip over they could result in a fire. DANGER: Do not open the cover or back, or remove any panels, or try to modify or repair the dm78/88. Opening the dm78/88 may expose you to dangerous voltages and will void the warranty. WARNING: The Standby/On mode switch does not disconnect the unit from the mains power. To disconnect the unit from the mains, switch off the unit at the mains socket outlet and withdraw the mains plug from the socket outlet. Protection from fluids The Halcro Logic dm78/88 units are designed for indoor use only and are not protected against liquids. They must not be exposed to dripping or splashing and no objects filled with liquids, such as vases, should be placed on them. If liquid is accidentally spilled on the device, immediately disconnect the unit from the mains. Allow sufficient time for complete evaporation before using the dm78/88 again. If the liquid is anything other than water, do not use the device before a qualified service technician has examined it. 5 Cleaning may be performed with a slightly damp cloth that has been wrung until nearly dry. Refer to the section on Cleaning on page 24. WARNING: To reduce the risk of fire or electric shock, do not expose this equipment to rain or moisture. Do not allow liquids to enter the unit or contact electrical terminals. DANGER: Always disconnect the unit from the mains before touching the loudspeaker terminals or replacing the fuse. Protection from overheating The dm78/88 generates a certain amount of heat and requires ventilation. Slots and ventilation holes are provided for ventilation purposes, and to ensure reliable operation of the product. To prevent fire hazards, these openings must never be blocked or covered. Follow the precautions listed below. If these precautions are not followed, overheating or failure may result. Overheating also shortens the working life of all components. · do not block the ventilation slots in the sides of the unit with any object, including paper, cloths or curtains avoid placing the unit in a built-in installation place such as a bookcase or a rack unless you can provide proper ventilation do not operate the unit inside a cabinet unless it has adequate ventilation (such as an open back panel) allow at least 12 in (300 mm) clearance around the unit Service warnings All compartments are sealed at the factory. If the seals are broken, the warranty will be void and all service costs will be charged to the owner. DANGER: Contains no user serviceable parts. Do not attempt to open any of the dm78/88 compartments as this may expose you to dangerous voltages and will void the warranty. Requires F 10 A L 250 V fuse for continued protection against the risk of fire. Never bypass or use any other type of fuse. The fuse is located on the bottom of the lower panel of the power amplifier (13). · · · WARNING: Always replace the fuse with the same type and rating as specified: F 10 A L 250 V. WARNING: Do not obstruct ventilation slots in the chassis. 6 Lifting or moving WARNING: Weighs 55 kg (120 lb) per unit. Shipping weight is 85 kg (187 lb). Never lift the amplifier by yourself. Wiring to the loudspeaker terminals to Class 2 wiring (US wiring regulations) This equipment has been classified as having a Class 2 loudspeaker output requiring wiring to connect the output terminals to class 2 according to the National Electrical Code. Consult a qualified installer or electrical contractor for further information. 120lb Always use two people to unpack or move the amplifier. Always bend at the knees when lifting. Do not strain your back. 7 Additional Important Safety Instructions for US The following instructions should be followed by customers in the USA in addition to the safety instructions in the rest of this chapter: o o o o o o o o o Read these instructions. Keep these instructions. Heed all warnings. Follow all instructions. Do not use this apparatus near water. Clean only with dry cloth or according to the cleaning instructions. Do not block any ventilation openings. Install in accordance manufacturer's instructions. with the o o o o Protect the power cord from being walked on or pinched particularly at plugs, convenience receptacles, and the point where they exit from the apparatus. Only use attachments/accessories specified by the manufacturer. Unplug this apparatus during lightning storms or when unused for long periods of time. Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been damaged in any way, such as if the power-supply cord or plug is damaged, liquid has been spilled, or objects have fallen into the apparatus, if the apparatus has been exposed to rain or moisture, does not operate normally, or has been dropped. . Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce heat. Do not defeat the safety purpose of the polarized or grounding-type plug. A polarized plug has two blades, with one wider than the other. A grounding type plug has two blades and a third grounding prong. The wide blade or the third prong is provided for your safety. If the provided plug does not fit into your outlet, consult an electrician for replacement of the obsolete outlet. o 8 Interference Warning - US FCC Regulations This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures: o o Increase the separation between the equipment and receiver. Connect the equipment into an outlet on a circuit different from that to which the amplifier is connected. Consult the dealer or an experienced radio/TV technician for help. Changes or modifications not expressly approved by Halcro could void the user's authority to operate the equipment. o 9 For Consumers within the European Union: The following instructions should be followed by customers in the EU in addition to the safety instructions in the rest of this chapter: o Do not dispose of this equipment in general household waste or unsorted municipal waste. The crossed out wheeled bin indicated on this equipment is an indicator that this unit should not be disposed of in general household waste, but recycled in compliance with local government regulations or environmental requirements. o Please dispose of this equipment via a recycling service or centre, or by returning the unit to the local Minelab/Halcro distributor. This will enable the equipment to be disposed of in an environmentally safe manner. o Disposal of unwanted waste electronic equipment in landfilled waste may contribute to adverse long term environmental effects due to the leaching of contaminating and/or toxic substances contained within some electronic equipment. 10 Installation Ensure you have read the Important Safety Information on page 3, before installing your Halcro amplifier. If you require assistance in the unpacking and installation of your Halcro amplifier, please contact your dealer. Do not connect to mains power until all the connections are made and checked. NOTE: When lifting the unit, always use two people. The unit must be lifted by placing your hands under the middle of the bottom compartment. Do not lift the unit under the top compartment. Storing packaging The packaging is custom designed to prevent damage from occurring during transport. Store the packaging in a dry location. Positioning We suggest that the Halcro amplifiers be positioned as near to your loudspeakers as practical. This will reduce the length of the loudspeaker cable required. The sides of the unit house the heat sinks that are used to dissipate heat. The airflow to these should not be interrupted. Ensure there is at least 12 inches (300 mm) clearance around the unit. Unpacking o Unscrew the four knurled knobs at the base of the container, and then remove the upper part of the container by lifting directly upwards until it clears the top of the amplifier. With an assistant, remove the plastic wrapping and foam pieces, then lift the amplifier from the base of the container. Remove the plastic covering from the unit. Wearing the white cotton gloves provided (to prevent marking the amplifier while moving it into place) move the unit to its final location (see Positioning). o o o 11 Controls and Connections Connecting the loudspeakers The dm78 and dm88 have four loudspeaker terminals each: · · 2 x positive + (red bezel) 2 x negative - (black bezel) Connecting the external ground The dm78 and dm88 are equipped with a separate ground terminal, which may be used to reduce hum and ripple in some circumstances. The ground terminal has a green bezel, and is located either under the power supply (dm88) or on the connector panel on the rear of the unit (dm78). There may be high voltages present at the loudspeaker terminals, which may present an electric shock hazard if touched. Always ensure the unit is switched to OFF or Standby mode when connecting or disconnecting loudspeakers. All of the pure copper connections are finished with the highest-grade gold plating. o Ensure the positive terminal of the amplifier connects to the positive terminal of the loudspeaker to ensure correct phasing of the audio signal. The loudspeaker terminals will accept spade or hook terminals. Only fully insulated terminals should be used. o Ensure the loudspeaker terminals are securely tightened, but do not over tighten or you may damage the terminals. When connecting loudspeaker cables always ensure the conductive surfaces are not touching each other. DO NOT SHORT-CIRCUIT THE TERMINALS. Connecting the mains supply cable Connect the mains plug into the socket at the rear, on the base of the bottom compartment, which houses the power supply. Ensure the cable exits to the rear of the unit. Continue to read the following pages before connecting to the mains outlet. Bridging You may bridge the Halcro dm78 and dm88 amplifiers, for details please E-mail us at: service@halcro.com o Break-in period The dm78 and dm88 electronic break-in period is completed at the factory. A further break-in period is not required. 12 dm78 Inputs The dm78 has three switch selectable inputs, each having an associated input socket. Both the input sockets and switch are mounted on the top rear panel, and the switch must be operator set to indicate which input is required. The table below lists the properties of these three inputs. The balanced voltage input or current-mode input are most desirable for minimizing earth loop generated mains hum and ripple, or high frequency interference. Earth loop generated mains hum and ripple, or high frequency interference should not be a problem unless the source equipment is poorly designed. Sources with current-mode outputs are rare and are most likely to have an RCA output socket. The advantages of this source are that: Earth loop generated mains hum and ripple are minimized, and cable, plug and socket generated interference is minimized (from poor connections which may be affected by sound vibration for example). The unbalanced input is quite satisfactory so long as earth loop generated mains hum and ripple are not a problem. The input sockets may have active sources simultaneously connected to them. The selector switch selects the input to be amplified. Input styles Balanced voltage input Required output source impedance Low impedance. Standard preamplifier or CD player for example. Low impedance. Standard preamplifier or CD player for example. Very high impedance; "infinite." Input socket XLR Input impedance 100 kohms + 100 kohms Unbalanced voltage input Current-mode input RCA 100 kohms RCA 60 ohms 13 dm88 Inputs The dm88 has four switch selectable inputs, each having an associated input socket. The input sockets and switch are mounted on the top rear panel, and the switch must be operator set to indicate which input is required. The table below lists the properties of these four inputs. The balanced voltage input or current-mode input are most desirable for minimizing earth loop generated mains hum and ripple, or high frequency interference. Earth loop generated mains hum and ripple, or high frequency interference should not be a problem unless the source equipment is poorly designed. Sources with current-mode outputs are rare and are most likely to have an RCA output socket. The advantages of this source are that: Input styles Balanced voltage input Required output source impedance Low impedance. Standard preamplifier or CD player for example. Low impedance. Standard preamplifier or CD player for example. Low impedance. Standard preamplifier or CD player for example. Very high impedance; "infinite." Earth loop generated mains hum and ripple are minimized, and cable, plug and socket generated interference is minimized (from poor connections which may be affected by sound vibration for example). The unbalanced input is quite satisfactory so long as earth loop generated mains hum and ripple are not a problem. The minimal path input will result in the most pure sound; unless as above, earth loop generated mains hum and ripple is a problem. The input sockets may have active sources simultaneously connected to them. The selector switch selects the input to be amplified. Input socket XLR Input impedance 100 kohms + 100 kohms Unbalanced voltage input Minimal path voltage input Current-mode input RCA 100 kohms RCA 660 ohms RCA 60 ohms 14 Operation All or some of the input sockets may have active sources simultaneously connected to them. The selector switch selects the input to be amplified. o Once the external cables are connected to the unit, ensure the master ON/OFF switch is in the OFF position. The master ON/OFF switch is on the base of the lower compartment, near the mains socket on the unit. You will have to kneel on the floor at the back of the unit to access the switch. o o Plug the mains plug into a mains outlet. Switch the master ON/OFF switch to ON. The LEDs on the front and rear of the amplifier will glow red. This indicates the unit is in Standby mode. In this mode a small current is drawn from the mains supply, but the unit will not drive the loudspeakers. o Press the mode switch once to switch between Standby and ON modes. The mode switch is a small pressure switch accessed when standing at the front of the unit. It is located under the bottom lip of the top compartment. When the amplifier has been switched to ON, the LEDs on the front and rear will glow green. The amplifier is now ready to drive your loudspeakers. It is recommended that the unit be switched to Standby when not in use. It is safer to turn the mains power off when not using the dm78 or dm88 monoblock amplifiers for extended periods. However the amplifier may be left on in the Standby mode for periods between active use. If you wish to turn the mains power off, the amplifier has a minimal warm up period. 15 Electronic Protection and Reliability Electronic protection circuitry and amplifier reliability, alas, is an area sadly neglected by many high-end audio amplifier designers. Halcro has paid a great deal of attention to this area. · all Halcro integrated circuits are at least "industrial grade" rather than the usual "commercial grade" Industrial grade components are rated at least from ­40ºC to +85ºC whereas commercial grade components are only rated from 0 to 70ºC. In addition, the electronic specifications of industrial grade components are superior to commercial grade. Considering that most amplifiers run at significantly elevated temperatures, it can be seen from the table below that the Halcro high temperature rated capacitors are highly advantageous compared to the standard 85ºC rated devices. Components Our components are selected not only for performance but reliability as well, for example: · all Halcro electrolytic capacitors are rated at a minimum of 105ºC instead of the usual 85ºC rating The operational life of electrolytic capacitors is severely shortened at temperatures near the maximum temperature rating. This is shown in the table below. Electrolytic capacitor temperature rating 85ºC (most commonly used) 105ºC (used in Halcro amplifiers) Mean lifetime at 40ºC 50,000 hours 180,000 hours Mean lifetime at 85ºC 2,000 hours 8,000 hours Mean lifetime at 105ºC 0 hours 2,000 hours Typical data from a highly respected manufacturer 16 Output Current Limiting In terms of maximum available output current, there are basically three amplifier type options: · · an amplifier with a reasonable limit placed on the maximum available output current an amplifier with no limit placed on the maximum available output current, which will either blow a fuse or self destruct if excessive current is drawn, for example through a dead short an amplifier with a very high limit placed on the maximum available output current, but designed not to blow a fuse if this very high current is drawn types above), highly overload sounds may be overload sound may loudspeaker overloads suffers voltage overload. obvious "cracking" heard. Note that this also occur if a or if any amplifier · There is an expectation in the audiophile electronic industry that a high end amplifier should be capable of delivering exactly double the output current for a halving of the loudspeaker impedance (down to 1 ohm) at the maximum output voltage that the amplifier can produce. This requires an amplifier of the second and third type above. The table below lists an example of an amplifier rated at 150 watts output into 8 ohms. If the maximum current drawn from an amplifier with maximum available current limiting is reached under very loud music conditions (the first and third amplifier Loudspeaker load impedance Output power Peak output voltage r.m.s. output current Peak output current 8 ohms 4 ohms 2 ohms 1 ohm 150 W 300 W 600 W 1200 W 49 V 49 V 49 V 49 V 4.33 A 8.66 A 17.32 A 34.64 A 6.12 A 12.25 A 24.5 A 49.0 A 17 If the loudspeaker cable is inadvertently shorted out, these sorts of currents are quite capable of causing some cables to catch fire. We know of one such instance with an amplifier rated according to the table! As we do not wish to set your house on fire we have limited the peak output current to 15 A. One also has to question the belief that an amplifier should be capable of such unreasonably high output currents. Consider the following facts: · · most loudspeakers have impedances of 4 ohms (not 1 or 2 ohms) all valve amplifiers are output current limited, and yet the industry does not consider this a problem, which is inconsistent with the belief that maximum available current limiting is a problem all well designed loudspeakers have impedances that do not deviate excessively from their nominal impedances and hence no excessively high currents are required anyway if indeed a 4 or 8 ohm loudspeaker does have an impedance of 1 ohm at a particular frequency, one must wonder where the heat generated is dissipated if this load is predominantly resistive or why the coupling is so poor if this load is predominantly reactive Hence we believe that these excessively high output currents are: · · not required for well designed loudspeakers highly dangerous Many people have listened to maximum available current limited amplifiers played through different loudspeakers without encountering any current limiting problems that is, obvious "cracking" sounds at very loud listening levels, except for loudspeaker or voltage overloads which are independent of current limiting. Output transistor protection Halcro uniquely incorporates circuitry that accurately calculates the mean power dissipated in the power output transistors (power FETs). Another calculating circuit then may reduce the maximum available output current according to the heat-sink temperature and calculated average dissipated power in the transistors. The higher the heat-sink temperature, and the higher the mean power dissipated in the output transistors, the greater this reduction. This will only occur at very high heat sink temperatures and very high mean output powers. · · 18 Unusual output conditions The vast majority of amplifier faults show up as high positive or negative DC output voltages. An independent circuit in the Halcro amplifiers senses any unreasonable DC. output voltage and switches the amplifier off if this occurs. Likewise, if any excessive output current flows for an extended length of time, this also implies a fault and an independent circuit measures this and will shut down the amplifier. · all power supplies, including those for "housekeeping" Standby, active power factor correction and switch mode power etc check for under/over voltage and over current conditions the small signal power supplies have transient diode over-voltage protection. · Mains transient overload protection The mains input is protected against all but the most severe mains input transients. Three independent circuits achieve this: two surge absorbers and high energy inductive filtering. Power supply output current limiting To further reduce the possibility of fault conditions causing substantial damage, the power supply is limited in its maximum available average output current. Note that this level is higher than the amplifier's normal current limiting conditions. The power supply limit will only cut in under fault conditions. Input overload protection The inputs have over-voltage protection circuits, which will handle most typical input overloads. Internal power supply protection There are numerous power supply protection circuits, for example: · · two independent over temperature cut outs two independent master clock fault sensing circuits Amplifier inter-stage protection In addition within the amplifier stages, there are more than a dozen protection circuits. 19