SMD DD-1 - Troubleshooting the DD-1; Common DD-1 Problems and Solutions

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Troubleshooting:
Problem: The Distortion detected LED is always on
Solution: The headunit can’t handle a 0dB track. Use
the -5 or -10dB tracks or replace headunit.
Problem: The Distortion detected LED is always on
even when using -5 or -10dB tracks.
Solution: Make sure all EQs and Bass, Treble ect. are
set to Flat or 0. If problem still exists, headunit may be
defective and not able to produce a clean signal.
Replace headunit.
Problem: The signal, 40Hz or 1kHz detected LEDs
won’t illuminate
Solution: The headunit may not be able to put out the
required 1.2Vrms to be within the operating range of the
DD-1. See section Measuring the Headunit Through
an Amplifier.
Problem: The Distortion detected LED is still on
Solution: Make sure amplifier gains are all the way
down, if the Distortion detected LED is still on; the
amplifier may be defective. Try another source unit, if it
doesn’t change the problem replace amplifier.
Problem: While setting gains the Distortion detected
LED blinks on then off.
Solution: This is not a problem at all, this is an artifact of
the DD-1 being 100% analog. Analog is faster than
digital, and as such the DD-1 detects distortion in the
signal when the auto ranging circuit is switching ranges.
Think of a nice clean sine-wave, and then it gets