Audiothingies - CED tuner/suboctave

Not available for an uncertain time.

The CED module on one hand is used as an oscillator tuner with two different modes of operation and a LED chain for visualsation, on the other hand it can be a sub octave generator with adjustable octave. That's two modules in two HP only!

The CED'S tuner is very fast and accurate due to his 20kHz quartz, analyzing the input's frequency and showing the offset versus the next semitone with a LED chain. There are two modes of operation which are selected with the swith on top:

• In Strobe mode a LED moves downwards along the LED chain - the slower this happens the smaller the detune. A brighter LED shows the detected note, blinks at an +/-10 cent offset and blinks faster at 20 cents offset.
• In calibration mode a row of LEDs displays how far you are from perfect tune.
  • bright blinking LED = perfect tune
  • no LED = 0.5 cent detune
  • one LED = one cent
  • two LEDs = two cents
  • three LEDs = five cents
  • from four LEDs on five cents are added

The CED's tuner uses a frequency counter allowing to derive sub-octaves. The generated square wave (10Vpp) can oscillate one or two octaves below the input frequency. The octave is set with the button atop the module
Usually you should feed the module with waveforms like saw or square but weird sub-octave sounds are generated when you use complex material instead, e.g. a wavetable VCO or a FM'ed signal
Press the Mode button for two seconds to deactivate the tuner. Maybe the blinking LED get on your nerves when you only need a sub-octaver at the moment.
In case you don't intend to use the suboscillator circuit and to use the output as a audio thru instead to save multiples you can set this with jumpers.

Further settings:

• Base frequency of the module, from 432 to 445 Hertz, in steps of 0.5Hz
• LED brightness in four steps