Ashly DPX-100 Block Diagram, Distorted Sound, Excessive Hum or Noise, No Audio Output, No Output

Operating Manual - DPX-100 Graphic Equalizer - Compressor/Limiter

10. BLOCK DIAGRAM Distorted Sound

				SIG
2				CLIP
1 3
	EQ			6dB/15dB
	INPUT		GAIN		2
				3
	-
					1
		HPF
			15 BAND EQ
	+
	HPF In/Out			EQ In/Out
				EQ OUTPUT
	CHAIN
2
1 3	LIMITER
	INPUT			CLIP
	-		INPUT/OUTPUT METERS
	+	GAIN			3	2
			VCA			1
				OUTPUT
	GAIN REDUCTION DISPLAY			LEVEL
	RATIO				LIMITER
					LIMITER
				CHANNEL
			DETECTOR
	ATTACK			IN/OUT
			CIRCUIT	TH
	RELEASE			DETECTOR
				INSERT
				THRESHOLD

This will only be caused by too much signal which will show on the Clip LED. If the LED is not flashing, there is an overload some- where else in the signal path. Adjust the rela- tive gain of each component in your chain to keep everything at a comfortable level.

Excessive Hum or Noise

Hum will usually be caused by a ground loop between components. Try using the sug- gested balanced input and output hook-ups if the other pieces of equipment used in conjunction with your equalizer have balanced inputs and outputs.

Noise (excessive hiss) can be caused by insufficient drive signal. Make sure you are send- ing a nominal 0 dBu line level signal to the equalizer. Most noise problems occur because gain is applied to audio signals too late in the chain. For best performance, apply gain to in- dividual source signals as early as possible, like at the mixer input preamp section. As gain in- creases, it also boosts the noise content of that signal. Any cumulative noise built up in a mixed signal will only be increased by using an equal- izer as a gain device, so make every attempt to operate the equalizer with as little gain as pos- sible.

11. Equalizer Troubleshooting Tips

No Audio Output

Check AC power - is the pilot light on? Check in/out connections - are they reversed? Are you sure you have an input signal?

EQ Controls Do Nothing

Is the master EQ switch in?

The lowest and highest frequency sliders may be beyond the range of the program material or speakers and may produce little or no audible effect.

Peak Light Flashes or Stays On All the Time

If the peak light flashes, the signal level to the equalizer is too high. Turn down the gain. If it is on all the time, disconnect the input and output cables. If it is still on, the unit must be returned for service.

Note: Unshielded cables, improperly wired con- nectors, and cables with broken strands of wire are very common problems. Use quality cables with quality, cor- rectly wired connectors.

11.1Compressor/Limiter Troubleshooting Tips

No Output

Check AC power. Is the power switch on? Check input and output connections - are they reversed? Are you sure you have an input signal?

Controls Have No Effect

Is the limiter in/out switch in? Perhaps the ratio control is set too low to produce an audible effect or the input level is below threshold. Is the threshold LED light- ing up? If not, lower the threshold setting or increase the gain. Do not expect to hear any effect when the input level is below threshold, since the unit is simply a linear amplifier at those levels.

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