Ashly-DLM821-mix-sch 电路图 维修手册.pdf

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1、DLM-821 Stereo Ducking Line/Microphone Mixer Operating Manual ASHLY AUDIO INC. 847 Holt Road Webster, NY 14580-9103 Phone: (585) 872-0010 Toll-Free: (800) 828-6308 Fax: (585) 872-0739 RadioFans.CN 收音机爱 好者资料库 2 Operating Manual - DLM-821 Stereo Ducking Line/Microphone Mixer Table Of Contents 1INTRODU

2、CTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2UNPACKING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3AC POWER REQUIREMENTS . . . . . . . . . . . . .

3、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 4SECURITY COVERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 5CONTROLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4、 . . . . . . . . 4 6CONNECTIONS AND CABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 7TYPICAL APPLICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 7.1 Small Sound Reinforcement System . . . . . . . . .

5、. . . . . . . . . . . . . . . . . . . . . . . . . . . 7 7.2 Church, School Or Meeting Room Sound System . . . . . . . . . . . . . . . . . . . . . . . . . 7 7.3 Restaurant/Sports Bar System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 8TROUBLESHOOTING TIPS . .

6、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 9DIMENSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 10 SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7、 . . . . . . . . . . . . . . . . . . . . . . . 9 11 WARRANTY INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 12 SCHEMATIC DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-15 RadioFans.CN 收音机爱 好者资料库 3

8、Operating Manual - DLM-821 Stereo Ducking Line/Microphone Mixer 1. INTRODUCTION Congratulations on your purchase of an Ashly DLM-821 stereo ducking line level mixer. Features include eight balanced stereo inputs for line level sources, the first four inputs with switchable 30dB gain for low impedanc

9、e microphones. +18V phantom power and stereo/mono switch- ing is provided for inputs 1 through 4. A concentric level and pan control for each input adjusts channel volume and stereo position. A ducking circuit allows a signal on either channel 1 or 2 to duck (attenuate) the signal on channels 3 thro

10、ugh 8. Internally the DLM-821 can be configured for ch.1 pri- ority whereby a signal on ch. 1 has priority over the signal on ch. 2 and fully attenuates channels 2 through 8. Further- more, the ducking level can be configured for -20dB or -90dB, ch. 2 ducking may be disabled, and the left and right

11、signal ducking may be disabled independently. Ultra low noise summing amplifiers combine the channel signals for the main outputs. A pair of 6-segment LED meter arrays monitor the main output levels. Separate level controls are provided for stereo, mono, and headphone outputs. 2. UNPACKING As a part

12、 of our system of quality control, every Ashly product is carefully inspected before leaving the factory to ensure flawless appearance. After unpacking, please inspect for any physical damage. Save the ship- ping carton and all packing materials , as they were care- fully designed to reduce to minim

13、um the possibility of transportation damage should the unit again require pack- ing and shipping. In the event that damage has occurred, immediately notify your dealer so that a written claim to cover the damages can be initiated. The right to any claim against a public carrier can be forfeited if t

14、he carrier is not notified promptly and if the shipping carton and packing materials are not avail- able for inspection by the carrier. Save all packing mate- rials until the claim has been settled. 3. AC POWER REQUIREMENTS The DLM-821 will perform normally from 98 to 125 volts AC. Use only properly

15、 grounded AC recep- tacles. To reduce the risk of ground loop hum, use a cen- tral point for system AC power distribution. The AC line fuse is internal, and should only be changed by a quali- fied service technician. 4. SECURITY COVERS For installations where it is desirable to protect the front pan

16、el controls from tampering or accidental misadjustment, use the Ashly security cover, which is available in both single and double rack space sizes. In- stallation is simple and does not require removal of the equipment from your rack. See your Ashly dealer for details. ? RadioFans.CN 收音机爱 好者资料库 4 O

17、perating Manual - DLM-821 Stereo Ducking Line/Microphone Mixer 5. CONTROLS 5.1 Ducking Enable Pressing this switch enables a signal present on inputs 1 or 2 to duck (attenuate) the signals on inputs 3 through 8. See sections 5.14 through 5.17 for internally selecting different ducking configurations

18、. 5.2 Channel Level and Pan The inner knob is the individual channel volume control which feeds a channel to the main mix. The 5 position corresponds to unity gain. The outer knob is the Pan control and adjusts the position of the channel in the stereo mix. 5.3 Mute Switch This switch on each channe

19、l will turn the chan- nel completely off allowing the channel level to remain at its desired setting when the input is not needed. 5.4 Mic/Line Switch This recessed switch on the first four inputs in- creases the channel input sensitivity by 30 dB to allow the use of low impedance microphones. The a

20、djacent yellow LED on indicates the switch is depressed and 30dB of gain is added for that channels mic input. 5.5 Output Meters A pair of peak detecting 6-segment LED meters are used to indicate output level. Green LEDs are used below 0 VU, yellow above 0 VU, and red LEDs indicate clipping. This me

21、ter pair monitors the main stereo out- put (0 VU = +4dBu). The red clipping LEDs also moni- tor all input channels, making it possible for these indicators to illuminate even with the stereo output level turned off. 5.6 Stereo Output Level and Pan This is the main master gain which sets the oper- at

22、ing level for the entire mixer. The 5 position corre- sponds to unity gain. This control does not effect the mono output level. 5.7 Stereo Output Mute This switch entirely mutes the main stereo out- put. The headphone and mono output are not affected. This is particularly useful when the DLM-821 is

23、used as a sub-mixer. 5.8 Mono and Headphone Level The inner knob is the master gain control for the mono output, which is the combined signal of the left and right outputs. It has no effect on the stereo output. Note: The mono output level can be selected between mic or line level. (see sec. 5.10) T

24、he outer knob is the level control for the front panel headphone jack. ? ? 5 Operating Manual - DLM-821 Stereo Ducking Line/Microphone Mixer 5.9 Power Switch The DLM-821 power switch is on the back panel. When it is pressed in the front panel power LED will be- come lit. 5.10 Mono Output Mic/Line Sw

25、itch This switch selects between a 0dBu (out posi- tion) line level or -40dBu (in position) mic level signal feeding the Mono output connector. 5.11 Stereo/Mono Input Switches These four pushbutton switches allow selection between a stereo or mono signal connection to input chan- nels 1 through 4 re

26、spectively. In the Out position, stereo left and right cables should be connected. In the in posi- tion, a mono cable should be connected to the R(Mono) connector which then internally feeds the signal to both left and right sides. 5.12 Phantom Power Switches There is a phantom power switch for chan

27、nels 1 and 2 and a phantom power switch for channels 3 and 4. Pushing the switch in applies +18VDC to the (+) and (-) input terminals of the two associated channels to power condenser mics. The input channels should be muted using the On/Mute switches when switching phantom power on or off to avoid

28、any pop noises. Internal PCB Jumper Options: 5.13 Ch. 2 Detect Enable * Internal jumper J1 allows enabling or disabling the ducker detector for ch. 2. (factory default is enabled) 5.14 Ducking Level * Internal jumper J16 allows selection between -20dB ducking level and -90 dB ducking level. (factory

29、 default is -20dB) 5.15 Ch. 1 Priority * Internal jumper J6 allows enabling ch. 1 to have priority over ch. 2 and fully attenuate channels 2-8. This feature is useful for applying an emergency page or alarm on channel 1 and applying a normal host page input on ch. 2. (factory default is ch.1 priorit

30、y disabled) 5.16 Left and Right Ducking Enable * Internal jumpers J14 and J15 allow the left and right signal ducking to be enabled or disabled indepen- dently. (factory default is left and right ducking enabled) * For internal jumper adjustments, remove AC cord from rear of unit and refer to a qual

31、ified service technician. (see PCB jumper locations in fig. 5.2) ? ? 6 Operating Manual - DLM-821 Stereo Ducking Line/Microphone Mixer Ashly Audio Inc. ? Fig. 5.2 - DLM-821 Internal Jumper Locations 6. CONNECTIONS AND CABLES 6.1 Inputs The DLM-821 stereo inputs use two 20k ohm balanced (10k ohm unba

32、lanced) Euroblock connectors per channel. Wire the (+) signal to the (+) terminal, the (-) signal to the (-) terminal, and the shield to G. If an unbalanced (two conductor) input signal is used, connect the shield to both (-) and G. To drive a mono source into the stereo mix, simply plug the signal

33、into the right channel input and press the Mono switch in. Additionally, channels 1 through 4 are switchable to mic level (see sec. 5.4) to add 30dB gain for microphone inputs. 6.2 Main and Mono Outputs Outputs are 200 ohm pseudo-balanced Euroblock connectors, which have bal- anced impedance with a

34、single-ended signal source and can be wired balanced or un- balanced. Nominal operating level is +4 dBu and maximum level is +23dBu. The Mono output is switchable to a nominal -40dBu microphone level. If wiring an output as unbalanced, use the (+) and G connections. If low level and high level lines

35、 (e.g., microphones and mixer line outputs), or if either of these lines and speaker cables are run parallel for long distances, crosstalk may be significant. In fact, the crosstalk (signal leakage between cables) can cause an electronic feedback loop, oscillation, and possibly damage to the equipme

36、nt. To mini- mize crosstalk, physically separate low level (microphone) cables from speaker cables by the greatest feasible distance. At any point where cables meet, run low level cables perpendicular to high level or speaker cables. If low and high level or speaker cables must be run parallel and i

37、n close proximity to one another, they should be bundled separately. Shielded cable should always be used for mic and line cables. Euroblock Input Connections +- G +- G +- G +- G Unbalanced Input Balanced Input + - G + - G + - G + G Unbalanced Output Balanced Output Euroblock Output Connections 7 Op

38、erating Manual - DLM-821 Stereo Ducking Line/Microphone Mixer 7. TYPICAL APPLICATIONS 7.1 Small Sound Reinforcement System In the setup shown here, the DLM-821 is used to mix typical sound sources that might be found in a small club, school theater or similar environment. INPUT channels 1 & 2 are us

39、ed for microphones for live vocal or instru- mental pickup. INPUT channels 3-8 are used for the output of electronic music devices such as keyboards, MIDI sound modules, drum machines, etc. The power amplifier (or any additional graphic equalizers or electronic cross- overs which may be used) is fed

40、 from the MAIN OUTPUT connectors. 7.2 Church, School Or Meeting Room Sound System: Here the DLM-821 is used to mix sources typically found in a church, classroom, or meeting room. The channel 2-4 inputs are used for microphones for live vocal or instrumental pickup. Channel 1 is fed by an alarm sign

41、al which will have priority and fully attenuate all other inputs if it is receiving an input signal. Channels 1 through 4 will have their Stereo/Mono switch pushed in. The remaining INPUT channels are used for audio outputs from video/DVD players, cassette deck, CD player, computer sound card, etc.

42、One input channel is reserved as a spare. The power amplifier (or any additional equalizer or electronic crossover which may be used) is fed from the MAIN OUTPUT connectors. The Mono output is connected into the wall mic jack to feed the mix into the buildings main PA system. Here the Mono Output se

43、lector switch should be pushed in for a mic-level signal. Microphone ? ? ? ? ? ! ? ?#$?%? !?&? ? #?&?$? ?&? &$? #?%?(? &? ? ? )?$? ?%?#& ? ?$?(?$? Microphone ? ?*? ? ?+?,? ?- ? ? ? ? ?!?#$? ?$? ? #?%?$? ?.? 8 Operating Manual - DLM-821 Stereo Ducking Line/Microphone Mixer 7.3 Restaurant/Sports Bar S

44、ystem: In this application, a variety of line level audio signals (tape, CD, satellite background music and TV) are fed into line inputs five through eight. Talent mics are fed into inputs three and four. A host paging mic is fed into input 2 which will duck (attenuate) three through eight. An emerg

45、ency paging mic is fed into input one and channel one priority is internally selected. An emergency page signal will then fully attenuate all other inputs. Inputs one through four should all have their Stereo/Mono switches pushed in. The Mono output is fed into an existing mic mixer/PA amplifier. Th

46、e Mono output Mic/Line switch should be pushed in to give a mic-level output to this existing mic mixer. Talent Mics ?&? ? ? ?!?#$? ?$?/? ? #?%?$? .? ?$?.!?%? 0? ? 1? #? ?#? ? ? ? ? 8. TROUBLESHOOTING TIPS 8.1 No Sound Check the AC power. Is the power switch on and illuminated? Check the level meter

47、s. If they are operating, the problem between the mixer and the later components in the system. If not, check to see you really have an input signal and that it is on the desired channel. Check that you have the master gain controls at the desired operating level. 8.2 Distorted Sound Something is be

48、ing overdriven in the signal path. If the clip indicators are active, reduce the channel level con- trols. If the clip indicators are still active, reduce the input signal level. If the level meters are constantly in the red, reduce the Master gain and increase the gain of components following the mixer. There are many