DaytonWright-999-pre-sm维修电路原理图.pdf

OWNERS MANUALTHE DAYTON WRIGHT Model 999 PRE-PREAMPLIFIERMark 1DAYTON WRIGHT GROUP LTD.97 Newkirk Road North, Richmond Hill,Ontario L4C 3G4, CANADARevised: February 22, 1985TABLE OF CONTENTSPage 1 of 26DW 999 Pre-preamplifier Manual12-12-2019mhtml:file:/C:UsersSlgerDownloadsDayton-Wright 999 Pre-preamplifier Manua.RadioFans.CN 收音机爱 好者资料库Section Title (Page in printed manual)GENERAL INFORMATION 1.1 Introduction.(4) 1.2 Description.(4) 1.3 Warranty.(4) 1.4 Identification .(5) 1.5 Inquiries .(5)INSTALLATION 2.1 Introduction. (6) 2.2 Initial Inspection. (6) 2.3 Claims. .(7) 2.4 Preparation for use .(7) 2.5 Repacking for shipment.(7) OPERATION 3.1 Introduction .(9) 3.2 Controls & Connectors. (9) 3.2l Use of BNC Connectors. (9) 3.22 Making up cables.(10) 3.23 Adaptors.(10) 3.24 Control Location.(11) 3.25 Load Resistors. .(11) 3.26 Opening the Case.(12) 3.27 Custom Loading .(13) 3.28 Output Level Adjustment.(13) 3.3 Power Supply Module.(14) 3.4 Hum & RF Problems.(14)PRINCIPLESOFOPERATION4.1 Introduction.(15)4.2 General Theory.(15)4.3 Block Diagram .(16)4.4 Specifics.(17)4.4l Input Cascode Stage.(17)4.42 Current Sink .(18)4.43 Buffer & Second Cascode Stage. (18)4.44 Output Stage. (18)4.45 Regulators.(19)4.46 Power Supply Module. (19)(page 2)PERFORMANCE CHECK 5.1 Introduction .(20) 5.2 Equipment Required .(20)Page 2 of 26DW 999 Pre-preamplifier Manual12-12-2019mhtml:file:/C:UsersSlgerDownloadsDayton-Wright 999 Pre-preamplifier Manua.RadioFans.CN 收音机爱 好者资料库 5.3 Distortion Measurement. (21) 5.4 Frequency Response Measurement (21)REPLACEMENT PARTS 6.1 Introduction. (22) 6.2 Parts List. (23) 6.3 Ordering Information .(25)SCHEMATICS & TROUBLE SHOOTING 7.1 Introduction .(27) 7.2 Schematics .(28) 7.4 Circuit Board Layout. (30) 7.5 Troubleshooting. (31) 7.51 DC Voltages .(32) 7.6 Dis-assemble& Reassembly (32) 7.7 Switch Maintenence.(32)(page 3)SECTION 1GENERAL INFORMATIONIntroduction:1.1 This manual covers the installation, operation, and servicing of the Model Dw 999 Pre-preamplifier.Description:1.2 The DW-999 is a Infranoise (very low noise) Pre-preamplifier which is designed to amplify the low level low-impedance signals from a moving coil type of phono cartridge to the level where they are sufficient to drive the phono input of a conventional preamplifier. This unit permits the user to select among several cartridge load resistances, and if necessary, to install a special resistor to match the required load. The circuit components are mounted on a double sided MIL-Grade-Epoxy Glass Circuit Board which is housed in a robust welded aluminum case. The Circuit Board is selectively coated with a solder resist on both sides in order to prevent solder bridging. The Power Supply is built into a separate case and supplies 30 volts DC to each channel of the pre-preamplifier. Both sections of the supply are electrically isolated from each other. The Left and Right Channels of the Pre-preamplifier are both electrically and physically isolated from each other on the circuit board in order to minimize any interaction. Both channels have individual and separate grounds. As supplied, the unit operates off 95 to 130 volts, 50 to 60 Hz mains. The power supply cord supplied is suitable for use in Canada and the United States of America. Other operating voltages and cords can be supplied upon request.Warranty:1.3 The DW999 is warranted in the Continental United Statesof America and Canada under a LIMITED WARRANTY as follows:This Dayton Wright Product is warranted against defects in both materials and workmanshipfor a period of Two Years from the date of manufacture, or from a period ofPage 3 of 26DW 999 Pre-preamplifier Manual12-12-2019mhtml:file:/C:UsersSlgerDownloadsDayton-Wright 999 Pre-preamplifier Manua.up to two years from the date of customer Purchase, the latter in nocase to exceed three years from the date of manufacture and in no caseto be valid unless the customer has his original Bill of Sale clearlyshowing the Date of Purchase and the Name and address of the dealerfrom whom this unit was purchased. This warranty is voidedwhere this unit has been subject to misuse or abuse.Any usage of acid-core solder on this unit void the warranty as does anyattempt to modify the circuit and/or the components used in its manufacture.Once return is authorized and the unit returned prepaid to the factory, wewill repair or replace any parts which prove to be defective within normal usageand provided the warranty has not expired. The Dayton Wright Group Ltd.,s decisionas to whether a unit has been abused shall be final and binding.No other warranty is expressed or implied and The Dayton Wright Group Ltd.is not liable for consequential damages.Exclusion for damage due to a lightening strike or power surge. Our warranty does not cover anything that is damaged by any incident like this. As transistors or other components may fail if subjected to a voltage spike, even after some months have passed, if we are called on to effect a repair, any such work will be excluded from any subsiquent warranty repair. It must be understood, in advance, that should we attempt a courtesy repair, tat it is NOT under any warranty whatsoever!You may have additional warranty rights in certain States.Outside the United States and Canada your warranty will be with the designated import agent for this product.In the Continental United States and Canada, for Warranty return authorization contact:This information is given only as it was supplied with the 555 Pre-preamplifier and may no longer be current! The Dayton Wright Group Ltd. Customer Services 3-97 Newkirk Road Richmond Hill, Ontario, L4C 3G4, Canada,Old number:(416) 884-8586New number: (905 508-7500Identification:1.4 This manual applaes to the DW999 Pre-Preamplifier only. The Unit may be identified by the 1999 on the top of the case, the model and serial number located on the back of the case, and the serial number on the circuit board itself. The date of manufacture is also on the circuit board. Any attempt to alter any of these numbers will void the warranty.INQUIRIES:This information is given only as it was supplied with the 555 Pre-preamplifier and may no longer be current!1.5 Direct any inquiries to: The Dayton Wright Group Ltd., Customer Service,Page 4 of 26DW 999 Pre-preamplifier Manual12-12-2019mhtml:file:/C:UsersSlgerDownloadsDayton-Wright 999 Pre-preamplifier Manua. 3-97 Newkirk Road , Richmond Hill, Ontario L4C 3G4 Canada. Always identify the unit by the serial number and model number. Shipments to the above address will not be accepted unless prior arrangements have been made and a return authorization obtained. Out of country customers are advised that it is their responsibility to file the necessary export documents so that they will have proof of export and thus avoid payment of duties upon the basic value of the unit upon its re-entry to their country.(page 5)Section 2INSTALLATIONIntroduction:2.1 This section contains the information needed to perform an initial inspection of the DW 999 Pre-preamplifier as well as the installation steps normal to its use in an audio system. Also covered are the procedures to be followed if initial inspection reveals damage to the unit, as well as repacking of the unit for storage or reshipment.Initial inspection:2.2 This pre-preamplifier was inspected both electrically and mechanically before it was shipped to the dealer. While we advise the dealers that all shipments should be inspected for damage immediately upon receipt so that shipping damage can be noted on the manifest and a claim made against the carrier, we have no way of verifying that this has been done. It is wise therefore, to perform a careful physical inspection of the pre-preamplifier prior to its initial use. Inspect the packing material to see if there is any physical damage to the carton. If carton damage is present, make a note of its location and extent. Also note any signs that the carton has been exposed to excessive moisture. The pre-preamplifier case should be free of scratches or burnish marks. The interconnecting cable from the power supply should be free of cuts or blemishes. The connector screws should be in place on the connector or should be packedged separately. Four (4) sets of BNC Connectors are packed (In plastic Bags) with each pre-preamplifier. The chassis mounted BNC Connectors should not be damaged or bent. An inspection of the internal Circuit board may be done by removing the two screws on either end of the power connector at the rear of the case. This will allow the PC Board to be slid out. There should be no sign that any components have been broken, cracked or knocked free of the circuit board. Re-insert the board in the case and secure with the two screws that had been removed. If the Pre-preamplifier is connected and operated outside the case remember that certain board traces if shorted together or if short-circuited to ground, can cause the transistors to be blown. Location of these damaged parts and their replacement is not covered under your warranty. If it is necessary to operate the unit uncased, be sure that it is resting on an insulated surface. As there is no power switch on this unit. up to 35 volts will be present in the power supply section of the board.(page 6)Page 5 of 26DW 999 Pre-preamplifier Manual12-12-2019mhtml:file:/C:UsersSlgerDownloadsDayton-Wright 999 Pre-preamplifier Manua.Claims:2.3 The warranty is printed in paragraph 1.3 on pages 4 and 5. If shipping damage is present and you took delivery of the unit up at a dealers; it was his responsability to inspect the incoming material after shipment, any claim for damages must be setled between yourself and the dealer. If the unit was shipped to you by the dealer, and you find shipping damage, it is your responsibility to make a claim against the carrier involved within a period of 14 days for hidden damage, or 7 days for visible damage. If you failed to inspect the material upon receipt and gave the carrier a clear signature you might have difficulty in procuring a settlement. Nevertheless it is your responsibility to notify the carrier in writing within the statutory period (which is best done by registered-return receipt requested mail) and to insure that he arranges an inspection of the goods as soon as possible. Your dealer should assist you by providing a certified true copy of the Bill of Lading and the Invoice so that you can then make a written claim. Upon receipt of your written claim the carrier generally has 120 days in which to negotiate a settlement. The Dayton Wright Group Ltd. has packed your unit carefully in a manner sufficient to withstand the normal rigors of shipment. We therefore assume no responsibility for shipping damage.Preparation for Use:2.4 The unit should be unpacked and placed on a surface removed from any power transformers or other sources of magnetic AC interference. The power module cable may then be plugged into the rear of the pre-preamplifier and secured with the screws provided. We do not advise leaving these loose as inadvertent disconnection could cause a damaging transient to go through your audio system. See section 3.21 on instructions for attaching BNC Connectors to your audio interconnect cables. We use these rather than the more common phono connectors as we have found that they not only are more reliable, and have lower distortion and noise but that as their ground connects first and disconnects last, there is far less possibility of an inadvertent disconnection damaging the other equipment. Initially it is wise to place the unit in an easily accessible location as you may wish to alter the load resistor settings and the output level controls. Be sure that you know what load your cartridge requires. Remember that the OUTPLIT LEVEL controls are twenty turn (20) potentiometers.(page7)Repacking for Shipment or Storage:2.5 ALWAYS SAVE THE ORIGINAL PACKING MATERIAL! Whenever you wish to store the unit or re-ship it the pre-preamplifier must be packed securely. The Factory will not accept responsibility for units that have been returned to them and damaged in shipment due to faulty packing techniques and/or materials. Make sure that the cable connector is positioned so that it will not mar the finish on the pre-preamplifier or the power supply module.(page 8)Section 3OPERATIONIntroduction:3.1 This section covers the general operation of the DW 999 Pre-Preamplifier including its controls and its Page 6 of 26DW 999 Pre-preamplifier Manual12-12-2019mhtml:file:/C:UsersSlgerDownloadsDayton-Wright 999 Pre-preamplifier Manua.connections.Controls & Connectors:3.2 As noted, the DW 999 employs BNC Connectors for all Audio Signal Path Connections. As both these as well as phono connectors are used in video recording, BNC-to-Phono cables are usually available from dealers handling video accessories. We do not advise the employment of phono adaptors as these simply re-introduce the problems that we tried to avoid by using BNC units in the first place.Use of BNC Connectors:3.31 The BNC Type of connector is in use world-wide as a wide-bandwidth low-noise connector in applications ranging from avionics to test equipment. As such, it may be readily obtained from electronics parts houses. While lower cost units are nickel plated, the better quality units are plated with either silver or gold. Besides the aforementioned advantage of making the ground connection first (upon connection) and breaking it last (upon disconnection) the BNC unit has a bayonet type locking device to hold it in place. In general, the cable-mounting portion of the connector system consists of a machined body upon which the positive bayonet-type-locking sleeve revolves. This body also has the slit sleeve ground connection which in turn surrounds a plastic insert which separates the outer grounded body and the inner live center pin. From the rear, a bushing screws into the main body and through of a tapered metal washer, a flat washer, and a rubber ring, connect the outer braid of the coaxial cable used to the connector body. This bushing is available in several different sizes and a size can usually be found that will fit whatever audio interconnect cable is being employed. Several manufacturers offer prefabricated cables with BNC connectors already attached at one or both ends.(page 9)Making up Cables:3.22 A bushing should be used that is a snug fit over the insulation of the coaxial cable being used.Page 7 of 26DW 999 Pre-preamplifier Manual12-12-2019mhtml:file:/C:UsersSlgerDownloadsDayton-Wright 999 Pre-preamplifier Manua.(page10)Adapters:3.23 Because of the amount of Video equipment that uses BNC connectors, most retailers who sell video recording equipment have a selection of BNC to Phono cables and adapters. While these are generally satisfactory for the connection of the Pre-preamplifier to the preamplifier (providing the length of the cable is not too long) they exhibit the usual noise problems when used in