Samson MPL 1204 - Manual

8 Guided Tour - Main Section 1: Auxiliary Return Level (orange) - These knobs determine the input level ofsignal arriving via the MPL 1204’s two stereo Auxiliary returns. The “0”(2 o’clock) position of each knob indicates unity gain (no level attenuation orboost). Moving each knob counterclockwise f...

Guided Tour - Rear Panel 1: Power on-off switch - As you may have guessed, this is what you use to turn theMPL 1204 on and off. To avoid potential damage to your speakers, turn the MPL 1204on before you turn on any connected power amps—and turn it off after the power ampsare turned off. 2: Fuse - Co...

13 Connecting The MPL 1204 - General Suggestions The actual connections you’ll make to and from the MPL 1204 will varyaccording to the environment you use it in and the particular equipment youhave. In the “MPL 1204 Applications” sections at the rear of this manual,you’ll find some suggested setups....

15 Setting up your MPL 1204 is a simple procedure which takes only a few minutes: 1. Remove all packing materials (save them in case of need for future service)and decide where the unit is to be physically placed—it can be mounted in anystandard 19" rack, requiring four rack spaces, or used on a...

16 You’re now ready to establish the correct gain structure—the key to getting thebest performance from the MPL 1204, or from any mixer, for that matter. This isa simple procedure that ensures optimum input and output levels so that nounnecessary noise (caused by too low a signal) or overload distor...

18 Grounding Techniques Hum and buzz are the biggest enemies you face when interconnecting a large number of different pieces ofequipment to a central audio mixer. This is because each piece of equipment may operate at a marginally differentvoltage (this difference is called potential) and, when two...

19 Busing, Submixing and Channel Muting As we’ve seen, the MPL 1204 uses a system of four buses—pathways throughwhich signal can be routed. The four MPL 1204 bus faders control the overalllevel of the signal being output through the four buses. When the “L/R” switchesabove each bus fader are pressed...

20 Using Pan The final Main output of the MPL 1204 is stereo—that is, there are two discreteMain output jacks (and two discrete Control Room output jacks), labeled “left”and “right,” which will normally be routed to two discrete speakers.* Because ofthis, you will usually be working with a stereo fi...

21 Using Equalization One of the most exciting aspects of using a mixer such as the MPL 1204 is theability to shape a sound, using a process called equalization. But there are fewareas of sound engineering more misunderstood than equalization, and, just asgood EQ can really help a sound, bad EQ can ...

22 Using Aux Sends and Returns The MPL 1204’s two Auxiliary sends allow you to combine the signal frommultiple channels and send the resulting mix to external devices such as effectsprocessors. When an Aux send knob is at its 2 o’clock “0” position, the signal isrouted with unity gain (that is, no b...

23 Using Inser ts In addition to using Auxiliary sends and returns to access outboard devices, theMPL 1204 also provides channel inserts for each of its twelve input channels.These should be used when you want to affect just one input signal, as opposedto signal from several inputs—most often, this ...

25 Applications Here are four suggested applications for the MPL 1204; bear in mind that your particular circumstance may dictatechanges in these suggested signal connections and routings. Application 1 - Using The MPL 1204 As A Recording Mixer The MPL 1204 is optimized for use as a recording mixer ...

26 Application 2 - Using The MPL 1204 As A Main Live Mixer Here, the MPL 1204’s Main output is connected to the input of a power amplifier, and, from there, to PA speakers.Microphones and line level signals are connected to various channel inputs, and a two-track tape deck is connected tothe Tape/CD...

27 Application 3 - Using The MPL 1204 As A Keyboard Submixer Here, various keyboards and MIDI tone generators are connected to the channel line inputs of the MPL 1204. Signalprocessors are connected to Aux sends and returns and to channel inserts as required. The Main output can then berouted to a s...

Applications Application 4 - Linking The MPL 1204 With Other Mixers The provision of four rear-panel Bus inserts makes it easy to link multiple MPL 1204s or to link the MPL 1204 with othermixers, without the need to use up channel line inputs. As shown in this illustration, simply connect the main o...

29 Appendix A: Block Diagram SUM SUM SUM SUM LOW HIGH MID 3 BAND EQ LEVEL + H.A TRIM MIC(CH1-10) BALANCED -50dBU --- +4dBU PAN LINE (CH1-10) -30dBU INSERT (CH1-10) +4dBU AUX 2 AUX 1 AFL L BUS 1 AFL R SOLO ON/OFF PFL L PFL R B+ BUS 2 BUS 3 BUS 4 LOW HIGH MID 3 BAND EQ LEVEL + H.A TRIM MIC(CH11-12) BA...

30 Specifications Normal Limit 1. Frequency Response (±3 dB) Mic in to Main out DC ~ 65 kHz 20 Hz - 50 kHz Mic in to Aux Send DC ~ 65 kHz 20 Hz - 50 kHz Aux return to Main out DC ~ 160 kHz 20 Hz - 50 kHz Tape in to Main out DC ~ 65 kHz 20 Hz - 50 kHz 2. Total Harmonic Distortion (20 Hz to 20 kHz, wi...