PPM Series Outputs
The PPM mixers have two power amplifiers built in. A flexible arrangement of switches and jacks allow you to use those two amplifiers for any combination of main and monitor speakers.
SPEAKER Out (PPM)
These 1/4" TS jacks carry the outputs of the power amplifiers.
There’s power behind these jacks – 125
to 600 watts depending on the model. Don’t connect them to anything other than
passive speakers – not active speakers, not a record- er, not another mixer. PASSIVE SPEAKERS ONLY!
Caution: Don’t use standard guitar
cables to connect your speakers. Guitar cords are designed for line level signals
and low currents, not the high currents and voltages of speaker levels. Use heavy duty speaker
There are two SPEAKER OUT jacks for each ampli- fier. The jacks are wired in parallel.
POWER AMP 1 / MAIN | POWER AMP 2 / MONITOR |
SPEAKER OUT | SPEAKER OUT |
OUTPUT POWER: 250 WATTS / CHANNEL
MINIMUM SPEAKER LOAD: 2 OHMS / CHANNEL
When you connect two speakers to a single ampli- fier, the load presented to the amplifier is the parallel impedance of both speakers. The total (parallel) impedance must be two ohms or greater.
•Two 8 ohm speakers in parallel equals 4 ohms.
•Two 4 ohm speakers in parallel equals 2 ohms. The general formula for impedance in parallel is:
Z |
|
|
| 1 |
|
|
| etc. | |
1 |
| 1 |
| 1 | |||||
|
|
|
| + |
| + |
|
|
|
| Z1 | Z2 | Z3 | ||||||
|
|
| |||||||
In electronics, Z is the symbol for impedance. We don’t have a clue as to what word Z stands for.
Can you plug speakers with different impedances into the two jacks same amplifier? Sure, as long as
MIXER ANATOMY: CHAPTER 2
the total impedance isn’t lower than 2 ohms. Chances are, however, that the efficiency of the speakers will be different enough that they’ll produce noticeably different volumes. This may or may not be what you want.
Note that the stereo and mono PPM mixers have different labels on the speaker connectors. They also have different options for routing MAIN and MONITOR mixes to those two amplifiers.
There’s a convenient pushbutton to select the most common configurations. There are also patching jacks that allow you to rearrange things to your liking, or add an external power amplifier for more flexibility. See the PPM Applications for some suggestions
POWER AMP ROUTING | 408S 2 X 250W STEREO | |||
| STEREO MAINS | |||
| LEFT = MAIN |
|
|
|
| RIGHT = MONITOR |
|
|
|
EFFECTS |
| MAINS | MONITOR | |
(OVERRIDES INTERNAL EFX) |
| |||
EFX FOOT |
| L POWER | R POWER | LINE |
SWITCH | SEND | AMP IN | AMP IN | OUT |
LEFT RETURN | RIGHT RETURN | L MIXER OUT | R MIXER OUT | COMPRESSOR |
|
|
|
| OUT |
|
|
|
| IN |
On the stereo mixers, the choices for Power Amp routing are:
POWER AMP ROUTING - In
AMP 1 – MAIN Mono (left + right)
AMP 2 – Monitor
Or
POWER AMP ROUTING - Out
AMP 1 – MAIN Left Channel
AMP 2 – MAIN Right Channel
POWER AMP ROUTING | 408M2 X 250 WATTS | |||
AMP 1 | AMP 2 | |||
MAIN | MAIN |
|
|
|
MAIN | MONITOR |
|
|
|
EFFECTS |
| MAINS |
| |
(OVERRIDES INTERNAL EFX) | MONITOR | |||
EFX FOOT |
| POWER | POWER | LINE |
SWITCH | SEND | AMP 1 IN | AMP 2 IN | OUT |
| RETURN | MIXER LINE OUT |
|
|
|
|
|
| COMPRESSOR |
|
|
|
| OUT |
|
|
|
| IN |
On the mono mixers, the choices are:
POWER AMP ROUTING - In
AMP 1 – MAIN
AMP 2 – Monitor
Or
POWER AMP ROUTING - Out
AMP 1 – MAIN
AMP 2 – MAIN
On both the mono and stereo models, when the ROUTING switch is in the Out position, both power
|
|
Compact Mixer Reference Guide | 27 |
|
|