Gilderfluke&Co Sd-50 Audio & Show Controllers - Manual (Page 33)

if any. After the end of the DMX-512 data, any remaining channels will be padded out through the
512th channel.
H) ! Left Speaker Output (Sd-50/0, Sd-50/8, Sd-50/40)
I) ! Right Speaker Output (Sd-50/0, Sd-50/8, Sd-50/40)
Four position Screw Terminals. These are the two outputs of the Sd-50/xx‘s onboard Class-D ampli-
fier. This amplifier’s efficiency is near 90%. If you feed 100 Watts of twenty-four vdc into the Sd-50/xx’s
amplifier, you will get almost 100 Watts into your speakers. ‘Linear’ amplifiers have only about 20% effi-
ciency. Fully 80% of the power you put into them goes into the heatsink as waste heat. A 100 Watt linear
amplifier would only feed 20 Watts of power into your speakers, and 80 Watts into the heatsink. This makes
the Sd-50/xx’s amplifier roughly equivalent to what would be a 400 to 500 Watt linear amplifier!
If you are going to run your speakers at high SPLs, you will need to select speakers that can handle at
least a 250 Watts or more of continuous power each. Smaller speakers may clip or be damaged if run at
too high an output power level from the Sd-50/xx. Maximum output power is achieved with a pair of four
ohm speakers (or two pairs of eight ohm speakers, connected in parallel).
The amplifier outputs from the Sd-50/xx can be used with speakers of four to eight ohms impedance.
As with any amplifier, you can series/parallel a number of speakers, so long as the impedance remains
within limits.
The Sd-50/xx’s amplifier is well protected from short circuits and overheating, and will go back to work
a moment after a fault is removed. If the speaker impedance is too low and you are running at a high vol-
ume level, the amplifier may start to cut out. If you hear this, check the power supply voltage. If the input
voltage is dropping, you might simply be drawing too much power for the power supply and a larger supply
may fix your problem. If the power supply is OK, and you can’t increase the speaker impedance, then you
might simply be asking too much of the Sd-50/xx’s amplifier, and need to turn down the volume a tad.
If you wish to comply with FCC and CE standards for radio frequency emissions, you should use
shielded speaker wires with the Sd-50/xx. The shield should be attached to the power supply ‘negative’
terminal, which is immediately adjacent to the speaker terminals. This will not affect the sound quality from
the Sd-50/xx, but will make the FCC and CE folks happy. Shielded speaker lines were used during all CE/
FCC certification testing.
External amplifiers can be fed from the Line Level Outputs if more power than this is needed.
J) ! Left Line Output (Sd-50/0, Sd-50/8, Sd-50/40)
K) ! Right Line Output (Sd-50/0, Sd-50/8, Sd-50/40)
Female RCA jacks. These are the two line level outputs from the .Mp3/.wav player. They are
used for attaching an external amplifier to the Sd-50/xx.
L) ! ʻ¼ J6ʼ Inputs/Outputs (Sd-50/0, Sd-50/8, Sd-50/40)
Ten position IDS Connector. Note that this individual pins on this port can be used as inputs or outputs.
If a pin is being used for one, it is not normally used as the other at the same time.
Each ‘" J6’ cable is arranged in the following order:
wire function wire number color
circuit ground 1 brown
Input/Output data bit #7 2 red
Gilderfluke & Co.• 205 South Flower Street • Burbank, California 91502 • 818/840-9484 • 800/776-5972 • fax 818/840-9485
Sd-50/xx Manual / October 29, 2012 2:29 PM / page 33 of 120