Samson MPL 1204 manual

MIXER SAMSON ® MPL 1204[...]

Intr oduction 3 MPL 1204 Features 3 Guided T our 5 Overview 5 Channels 6 Main Section 8 Rear Panel 11 Connecting The MPL 1204 - General Suggestions 13 Setting Up and Using the MPL 1204 15 Setting the Correct Gain Structure 16 Gr ounding T echniques 18 Busing, Submixing, and Channel Muting 19 Using Pan 20 Using Equalization 21 Using Aux Sends and Re[...]

Intr oduction / MPL 1204 Featur es Congratulations on purchasing the Samson MPL 1204 four-bus microphone/line mixer! The MPL 1204 is optimized for use in both live performance and recording applications, and it can be used wherever there are a number of microphone or line-level sources that need to mixed down to two or four outputs. Although the MP[...]

MPL 1204 Featur es • Electronically balanced XLR Main stereo outputs as well as an independent electronically balanced stereo Control Room output (with dedicated level control) for connection to a power amplifier and studio monitors. • A phantom power switch enables you to use the MPL 1204 with high-quality condenser microphones. When turned on[...]

Guided T our - Over view The following illustration shows an overview of the front panel of the MPL 1204: 5 LEVEL LEVEL LEVEL LEVEL LEVEL LEVEL LEVEL LEVEL LEVEL LEVEL LEVEL LEVEL MUTE 3/4 LEFT RIGHT -20 -15 -9 -6 -3 0+ 2 + 4 + 6 +8 PFL AFL POWER MAIN LEVEL CONTROL ROOM CH 1 CH 2 AUX RETURNS STEREO SAMSON MPL 1204 MIC MIXER AFL PFL L R L R BUS 2 BU[...]

Guided T our - Channels 1: Trim (black) - This knob determines the input level of the connected signal. Continuously adjustable from +4 dB to -50 dB (for mic inputs) or +24 to -30 dB (for line inputs), the input signal is boosted when the trim is turned clockwise and attenuated when turned counterclockwise. For information on how to properly set th[...]

Guided T our - Channels 7: Level (white) - This knob (purposely made a little bigger than the others so you can find it easily in low-light situations) controls the volume of the channel input. In practice, you will use the Level controls to continuously adjust the loudnesses of the various signals being blended together by the MPL 1204. The “ 0 [...]

8 Guided T our - Main Section 1: Auxiliary Return Level (orange) - These knobs determine the input level of signal 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 or boost). Moving each knob counterclockwise from the “ 0 ” position (towa[...]

9 Guided T our - Main Section 3: Stereo Auxiliary Return Balance (brown) - These knobs determine the relative levels of the left and right input signals connected to the MPL 1204 ’ s two stereo Auxiliary returns. When the knob is placed at its center (detented) position, both left and right input signals for that Aux return are at equal strength.[...]

Guided T our - Main Section certain that one or more connected mics require 48 volts phantom power, leave this switch off (its out position). 10: Meter switch - When out, the ten-segment MPL 1204 meter (see #6 on the previous page) shows the continuous output level of Bus 1-2; when pressed in, the meter shows the continuous output level of Bus 3-4.[...]

Guided T our - Rear Panel 1: Power on-off switch - As you may have guessed, this is what you use to turn the MPL 1204 on and off. To avoid potential damage to your speakers, turn the MPL 1204 on before you turn on any connected power amps — and turn it off after the power amps are turned off. 2: Fuse - Contains a 1 amp, 250 volt fuse for 115 volt[...]

12 Guided T our - Rear Panel 7: Aux Returns (1/2, 3/4) - These unbalanced 1/4" TRS inputs allow you to route signal from external devices such as effects processors to either of the two stereo Aux Returns. These jacks accept 1/4" TRS plugs, with the tip carrying the left signal and the ring carrying the right signal (sleeve is common grou[...]

13 Connecting The MPL 1204 - General Suggestions The actual connections you ’ ll make to and from the MPL 1204 will vary according to the environment you use it in and the particular equipment you have. In the “ MPL 1204 Applications ” sections at the rear of this manual, you ’ ll find some suggested setups. Here are a few basic rules conce[...]

14 • NEVER connect a microphone and line level input to the same channel simultaneously — use one or the other. You can have some channels connected to microphones and others to line level signals (for example, you might want to plug mics into channels 1 - 4 and line level signals into the remaining channels) — just don ’ t have both kinds [...]

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 any standard 19" rack, requiring four rack spaces, or used on a tabletop. 2. Before even plugging the unit[...]

16 You ’ re now ready to establish the correct gain structure — the key to getting the best performance from the MPL 1204, or from any mixer, for that matter. This is a simple procedure that ensures optimum input and output levels so that no unnecessary noise (caused by too low a signal) or overload distortion (caused by too high a signal) is c[...]

17 Setting the Cor r ect Gain Str uctur e h. Once you ’ ve set the optimum level in step (g) above, continue playing the instrument and slowly raise the level of your power amplifier until you reach the desired listening level. Repeat step (g) above for each instrument connected to the MPL 1204 channel line inputs. i. The procedure for setting op[...]

18 Gr ounding T echniques Hum and buzz are the biggest enemies you face when interconnecting a large number of different pieces of equipment to a central audio mixer. This is because each piece of equipment may operate at a marginally different voltage (this difference is called potential ) and, when two devices at slightly different potential are [...]

19 Busing, Submixing and Channel Muting As we ’ ve seen, the MPL 1204 uses a system of four buses — pathways through which signal can be routed. The four MPL 1204 bus faders control the overall level of the signal being output through the four buses. When the “ L/R ” switches above each bus fader are pressed in, the signal from that bus is [...]

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

21 Using Equalization One of the most exciting aspects of using a mixer such as the MPL 1204 is the ability to shape a sound, using a process called equalization . But there are few areas of sound engineering more misunderstood than equalization, and, just as good EQ can really help a sound, bad EQ can really hurt it, so read on... Every naturally [...]

22 Using Aux Sends and Retur ns The MPL 1204 ’ s two Auxiliary sends allow you to combine the signal from multiple channels and send the resulting mix to external devices such as effects processors. When an Aux send knob is at its 2 o ’ clock “ 0 ” position, the signal is routed with unity gain (that is, no boost or attenuation). As it is t[...]

23 Using Inser ts In addition to using Auxiliary sends and returns to access outboard devices, the MPL 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 opposed to signal from several inputs — most often, this will be for dynamic processing purposes (su[...]

24 PFL/AFL Soloing The MPL 1204 provides two options for soloing input signals in headphones connected to the front panel headphone jack — Pre Fade Listen ( PFL ) and After-Fade Listen ( AFL ). The Solo switch in the main section (#8 on page 7) allows you to choose between these two modes of operation. Although they may at first glance appear sim[...]

25 Applications Here are four suggested applications for the MPL 1204; bear in mind that your particular circumstance may dictate changes in these suggested signal connections and routings. Application 1 - Using The MPL 1204 As A Recor ding Mixer The MPL 1204 is optimized for use as a recording mixer with multitrack digital or analog recorders. As [...]

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 to the Tape/CD inputs. A submix from Aux send 1 (which is [...]

27 Application 3 - Using The MPL 1204 As A Keyboar d Submixer Here, various keyboards and MIDI tone generators are connected to the channel line inputs of the MPL 1204. Signal processors are connected to Aux sends and returns and to channel inserts as required. The Main output can then be routed to a stereo input channel of a live performance or re[...]

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 other mixers, without the need to use up channel line inputs. As shown in this illustration, simply connect the main output of another mixer to one or two MPL 1204 Bus[...]

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) BALANCED -50dBU --- +4dBU PAN LINE (CH11-12 -30dBU I[...]

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, with 30 kHz LPF) Mic in to Main out (Trim max) 0.06[...]

Produced by On The Right Wavelength for Samson Technologies Corp. Copyright 1997, Samson Technologies Corp. Printed March 1997 Samson Technologies Corp. 575 Underhill Blvd. P.O. Box 9031 Syosset, NY 11791-9031 Phone: 1-800-3-SAMSON (1-800-372-6766) Fax: 516-364-3888[...]